Sync Source Changes :)

.classpath

@@ -6,12 +6,6 @@
 			<attribute name="gradle_used_by_scope" value="main,test"/>
 		</attributes>
 	</classpathentry>
-	<classpathentry kind="src" output="bin/main" path="src/main/resources">
-		<attributes>
-			<attribute name="gradle_scope" value="main"/>
-			<attribute name="gradle_used_by_scope" value="main,test"/>
-		</attributes>
-	</classpathentry>
 	<classpathentry kind="src" output="bin/test" path="src/test/java">
 		<attributes>
 			<attribute name="gradle_scope" value="test"/>

.github/workflows/coverage.yml

@@ -8,11 +8,11 @@ jobs:
     name: Code Quality Check
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v6
         with:
           fetch-depth: 0  # Shallow clones should be disabled for a better relevancy of analysis
       - name: Set up JDK 11
-        uses: actions/setup-java@v3
+        uses: actions/setup-java@v5
         with:
           distribution: 'temurin'
           java-version: 11

.gitignore

@@ -20,15 +20,7 @@ gradle-app.setting
 /bin/
 /storage/
 #Generated Code
-/src/main/java/speiger/src/collections/booleans/*
-/src/main/java/speiger/src/collections/bytes/*
-/src/main/java/speiger/src/collections/shorts/*
-/src/main/java/speiger/src/collections/chars/*
-/src/main/java/speiger/src/collections/ints/*
-/src/main/java/speiger/src/collections/longs/*
-/src/main/java/speiger/src/collections/floats/*
-/src/main/java/speiger/src/collections/doubles/*
-/src/main/java/speiger/src/collections/objects/*
+
 
 #Generated Tests
 /src/test/java/speiger/src/testers/booleans/*

gradle.properties

@@ -1,4 +1,4 @@
 org.gradle.jvmargs=-Xmx3G
 
-maxMemory = 1024m
-testThreads = 2
+maxMemory = 2048m
+testThreads = 4

src/builder/java/speiger/src/builder/PrimitiveCollectionsBuilder.java

@@ -128,6 +128,7 @@ public class PrimitiveCollectionsBuilder extends TemplateProcessor
 		for(int i = 0,m=modules.size();i<m;i++) {
 			modules.get(i).setManager(manager);
 		}
+		manager.resolve();
 		for(int i = 0,m=modules.size();i<m;i++) {
 			biPackages.forEach(modules.get(i)::init);
 		}

src/builder/java/speiger/src/builder/SettingsManager.java

@@ -1,54 +1,100 @@
 package speiger.src.builder;
 
 import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.OutputStreamWriter;
 import java.nio.file.Files;
 import java.nio.file.Paths;
+import java.util.ArrayList;
+import java.util.LinkedHashSet;
+import java.util.List;
+import java.util.Map;
 import java.util.Set;
+import java.util.TreeMap;
 import java.util.TreeSet;
 
+import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParser;
 import com.google.gson.internal.Streams;
 import com.google.gson.stream.JsonWriter;
 
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.IDependency.LoadingState;
 import speiger.src.builder.modules.BaseModule;
 
 @SuppressWarnings("javadoc")
 public class SettingsManager
 {
 	boolean loaded;
+	Map<String, LoadingState> parsedData = new TreeMap<>();
 	JsonObject data = new JsonObject();
 	Set<String> moduleNames = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
+	Set<IDependency> allDependencies = new LinkedHashSet<>();
 	
-	public boolean isModuleEnabled(BaseModule base, ClassType keyType, ClassType valueType) {
-		if(!loaded) return true;
-		if(!isEnabled(data, base.getModuleName())) return false;
-		JsonObject result = getObject(data, keyType.getClassPath(), false);
-		if(!isEnabled(result, "Enabled")) return false;
-		if(base.isBiModule()) {
-			result = getObject(result, valueType.getClassPath(), false);
-			if(!isEnabled(result, "Enabled")) return false;
+	public void resolve() {
+		if(!loaded) return;
+		Set<IDependency> roots = new LinkedHashSet<>();
+		Set<IDependency> leafs = new LinkedHashSet<>();
+		for(IDependency entry : allDependencies) {
+			if(entry.isRoot()) {
+				roots.add(entry);
+			}
+			if(entry.isLeaf()) {
+				leafs.add(entry);
+			}
+		}
+		/**
+		 * This has to be 2 iteration passes.
+		 * Due to Key Value Pairs, first pass does all initials keys, and the second pass processes the values.
+		 * May require more passes but extremely unlikely
+		 */
+		for(int i = 0;i<2;i++) {
+			for(ClassType keyType : ModulePackage.TYPE) {
+				for(ClassType valueType : ModulePackage.TYPE) {
+					for(IDependency entry : roots) {
+						entry.resolveRequirements(keyType, valueType);
+					}
+				}
 			}
-		result = getObject(result, base.getModuleName(), false);
-		return (result.size() <= 0 || isEnabled(result, "Enabled")) && base.areDependenciesLoaded();		
 		}
 		
-	public boolean isModuleEnabled(BaseModule base, ClassType keyType, ClassType valueType, String entry)
-	{
-		if(!loaded) return true;
-		if(!isEnabled(data, base.getModuleName())) return false;
-		JsonObject result = getObject(data, keyType.getClassPath(), false);
-		if(!isEnabled(result, "Enabled")) return false;
-		if(base.isBiModule()) {
-			result = getObject(result, valueType.getClassPath(), false);
-			if(!isEnabled(result, "Enabled")) return false;
+		List<String> errors = new ArrayList<>();
+		for(ClassType keyType : ModulePackage.TYPE) {
+			for(ClassType valueType : ModulePackage.TYPE) {
+				for(IDependency entry : leafs) {
+					entry.validateDependency(errors::add, keyType, valueType);
+				}
+			}
+		}
+		if(errors.size() > 0) {
+			throw new IllegalStateException("Issues with dependencies found: "+String.join("\n", errors));
 		}
-		result = getObject(result, base.getModuleName(), false);
-		return (result.size() <= 0 || (isEnabled(result, "Enabled") && isEnabled(result, entry))) && base.areDependenciesLoaded();
 	}
 	
 	public void addModule(BaseModule module) {
-		if(loaded) return;
+		if(loaded) {
+			if(module.isBiModule()) {
+				for(ClassType keyType : ModulePackage.TYPE) {
+					for(ClassType valueType : ModulePackage.TYPE) {
+						if(!module.isModuleValid(keyType, valueType)) continue;
+						for(IDependency dependency : module.getDependencies(keyType, valueType)) {
+							dependency.set(parsedData);
+							allDependencies.add(dependency);
+						}
+					}
+				}
+				return;
+			}
+			for(ClassType keyType : ModulePackage.TYPE) {
+				if(!module.isModuleValid(keyType, keyType)) continue;
+				for(IDependency dependency : module.getDependencies(keyType, keyType)) {
+					dependency.set(parsedData);
+					allDependencies.add(dependency);
+				}
+			}
+			return;
+		}
 		String moduleName = module.getModuleName();
 		moduleNames.add(moduleName);
 		data.addProperty(moduleName, true);
@@ -57,9 +103,9 @@ public class SettingsManager
 				for(ClassType valueType : ModulePackage.TYPE) {
 					if(!module.isModuleValid(keyType, valueType)) continue;
 					JsonObject obj = new JsonObject();
-					obj.addProperty("Enabled", true);
-					for(String key : module.getModuleKeys(keyType, valueType)) {
-						obj.addProperty(key, true);
+					for(IDependency dependency : module.getDependencies(keyType, valueType)) {
+						String key = dependency.getName();
+						if(key != null) obj.addProperty(key, true);
 					}
 					addModule(keyType, valueType, true, moduleName, obj);
 				}
@@ -69,18 +115,61 @@ public class SettingsManager
 		for(ClassType keyType : ModulePackage.TYPE) {
 			if(!module.isModuleValid(keyType, keyType)) continue;
 			JsonObject obj = new JsonObject();
-			obj.addProperty("Enabled", true);
-			for(String key : module.getModuleKeys(keyType, keyType)) {
-				obj.addProperty(key, true);
+			for(IDependency dependency : module.getDependencies(keyType, keyType)) {
+				String key = dependency.getName();
+				if(key != null) obj.addProperty(key, true);
 			}
 			addModule(keyType, keyType, false, moduleName, obj);			
 		}
 	}
 	
+	public void printModuleSettings(List<BaseModule> modules) {
+		JsonObject data = new JsonObject();
+		for(BaseModule module : modules) {
+			String moduleName = module.getModuleName();
+			if(module.isBiModule()) {
+				for(ClassType keyType : ModulePackage.TYPE) {
+					for(ClassType valueType : ModulePackage.TYPE) {
+						if(!module.isModuleValid(keyType, valueType)) continue;
+						JsonObject obj = new JsonObject();
+						for(IDependency dependency : module.getDependencies(keyType, valueType)) {
+							String key = dependency.getName();
+							if(key != null) obj.addProperty(key, dependency.isLoaded(keyType, valueType).getJsonResult());
+						}
+						addModule(data, keyType, valueType, true, moduleName, obj);
+					}
+				}
+				continue;
+			}
+			for(ClassType keyType : ModulePackage.TYPE) {
+				if(!module.isModuleValid(keyType, keyType)) continue;
+				JsonObject obj = new JsonObject();
+				for(IDependency dependency : module.getDependencies(keyType, keyType)) {
+					String key = dependency.getName();
+					if(key != null) obj.addProperty(key, dependency.isLoaded(keyType, keyType).getJsonResult());
+				}
+				addModule(data, keyType, keyType, false, moduleName, obj);			
+			}
+		}
+		try {
+			System.out.println();
+			JsonWriter writer = new JsonWriter(new OutputStreamWriter(System.out));
+			writer.setIndent("\t");
+			Streams.write(data, writer);
+			writer.flush();
+			System.out.println();
+		} catch (IOException e) {
+			e.printStackTrace();
+		}
+	}
+	
 	public void load() {
 		try(BufferedReader reader = Files.newBufferedReader(Paths.get("ModulSettings.json"))) {
 			data = JsonParser.parseReader(reader).getAsJsonObject();
 			loaded = true;
+			IDependency.flatten("", false, data, parsedData);
+			JsonElement element = data.get("Default");
+			LoadingState.setOptionalResolver(LoadingState.of(element == null ? true : element.getAsBoolean()));
 		}
 		catch(Exception e) { e.printStackTrace(); }
 	}
@@ -100,6 +189,14 @@ public class SettingsManager
 		catch(Exception e) { e.printStackTrace(); }
 	}
 	
+	private void addModule(JsonObject data, ClassType keyType, ClassType valueType, boolean bi, String moduleName, JsonObject obj) {
+		JsonObject result = getObject(data, keyType.getClassPath(), true);
+		if(bi) {
+			result = getObject(result, valueType.getClassPath(), true);
+		}
+		result.add(moduleName, obj);
+	}
+	
 	private void addModule(ClassType keyType, ClassType valueType, boolean bi, String moduleName, JsonObject obj) {
 		JsonObject result = getObject(data, keyType.getClassPath(), true);
 		if(bi) {
@@ -117,9 +214,4 @@ public class SettingsManager
 		}
 		return obj;
 	}
-	
-	private boolean isEnabled(JsonObject obj, String key) {
-		if(obj.has(key)) return obj.getAsJsonPrimitive(key).getAsBoolean();
-		return true;
-	}
 }

src/builder/java/speiger/src/builder/dependencies/BaseDependency.java

@@ -0,0 +1,137 @@
+package speiger.src.builder.dependencies;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
+import java.util.StringJoiner;
+import java.util.TreeSet;
+import java.util.function.Consumer;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.Requirements.Requirement;
+
+@SuppressWarnings("javadoc")
+public abstract class BaseDependency implements IDependency {
+	protected static boolean FETCH_FAILURES = false;
+	protected static Set<String> FAILURE_KEYS = new TreeSet<>();
+	
+	protected final String name;
+	protected final boolean biType;
+	protected Map<String, LoadingState> dependencies;
+	protected List<IDependency> children = new ArrayList<>();
+	protected List<Requirement> requirements = new ArrayList<>();
+	protected ClassType keyType;
+	protected ClassType valueType;
+	
+	public BaseDependency(String name, boolean biType) {
+		this.name = name;
+		this.biType = biType;
+	}
+	
+	@Override
+	public String toString() {
+		return name;
+	}
+	
+	@Override
+	public void set(Map<String, LoadingState> dependency) {
+		dependencies = dependency;
+	}
+	
+	@Override
+	public IDependency addDependency(Requirement require) {
+		requirements.add(require);
+		require.dependency.addChild(this);
+		return this;
+	}
+	
+	@Override
+	public void addChild(IDependency child) {
+		children.add(child);
+	}
+	
+	@Override
+	public boolean isLeaf() {
+		return children.isEmpty();
+	}
+	
+	@Override
+	public boolean isRoot() {
+		return requirements.isEmpty();
+	}
+	
+	protected LoadingState getGlobalState() {
+		return dependencies.getOrDefault(name, LoadingState.OPTIONAL);
+	}
+	
+	@Override
+	public String getLocalStateKey(ClassType keyType, ClassType valueType) {
+		return (biType ? keyType.getClassPath()+"-"+valueType.getClassPath() : keyType.getClassPath())+"-"+name;
+	}
+	
+	protected LoadingState getLocalState(ClassType keyType, ClassType valueType) {
+		return dependencies.getOrDefault(getLocalStateKey(keyType, valueType), LoadingState.OPTIONAL);
+	}
+		
+	protected LoadingState getReqirementState(ClassType keyType, ClassType valueType) {
+		LoadingState state = requirements.isEmpty() ? LoadingState.REQUIRED : LoadingState.OPTIONAL;
+		for(int i = 0,m=requirements.size();i<m;i++) {
+			state = state.merge(requirements.get(i).test(keyType, valueType));
+		}
+		return state.resolveIfUndefined();
+	}
+	
+	@Override
+	public void resolveRequirements(ClassType keyType, ClassType valueType) {
+		if(!children.isEmpty()) {
+			for(IDependency child : children) {
+				if(child == this) continue;
+				child.resolveRequirements(keyType, valueType);
+			}
+		}
+		if(getLocalState(keyType, valueType) == LoadingState.REQUIRED) {
+			for(Requirement req : requirements) {
+				dependencies.putIfAbsent(req.key(keyType, valueType), LoadingState.REQUIRED);
+			}
+		}
+	}
+	
+	@Override
+	public void validateDependency(Consumer<String> result, ClassType keyType, ClassType valueType) {
+		if(getLocalState(keyType, valueType) == LoadingState.REQUIRED) {
+			FETCH_FAILURES = true;
+			for(Requirement req : requirements) {
+				req.test(keyType, valueType);
+			}
+			FETCH_FAILURES = false;
+			if(FAILURE_KEYS.size() > 0) {
+				int size = FAILURE_KEYS.size();
+				StringJoiner joiner = new StringJoiner("], [", "[", "]");
+				FAILURE_KEYS.forEach(joiner::add);
+				FAILURE_KEYS.clear();
+				String joins = size > 1 ? "["+joiner.toString()+"]" : joiner.toString();
+				
+				result.accept("["+getLocalStateKey(keyType, valueType)+"] Requires "+joins+" but it specifically has been disabled!");
+			}
+			
+		}
+	}
+	
+	@Override
+	public void set(ClassType key, ClassType value) {
+		this.keyType = key;
+		this.valueType = value;
+	}
+	
+	@Override
+	public boolean isEnabled() {
+		if(keyType == null || keyType == null) return false;
+		return isLoaded(keyType, valueType).getJsonResult();
+	}
+	
+	@Override
+	public String getName() {
+		return name;
+	}
+}

src/builder/java/speiger/src/builder/dependencies/FunctionDependency.java

@@ -0,0 +1,29 @@
+package speiger.src.builder.dependencies;
+
+import speiger.src.builder.ClassType;
+
+@SuppressWarnings("javadoc")
+public class FunctionDependency extends BaseDependency {
+	ModuleDependency owner;
+	
+	public FunctionDependency(ModuleDependency owner, String name) {
+		super(name, owner.biType);
+		this.owner = owner;
+	}
+	
+	@Override
+	public LoadingState isLoaded(ClassType key, ClassType value) {
+		if(dependencies == null) return LoadingState.REQUIRED;
+		LoadingState result = getLocalState(key, value);
+		if(FETCH_FAILURES && result == LoadingState.REJECTED) {
+			FAILURE_KEYS.add(getLocalStateKey(key, value));
+		}
+		return result.resolveIfUndefined().merge(getReqirementState(key, value));
+	}
+	
+	@Override
+	public String getLocalStateKey(ClassType keyType, ClassType valueType) {
+		return (biType ? keyType.getClassPath()+"-"+valueType.getClassPath() : keyType.getClassPath())+"-"+owner.getName()+"-"+name;
+	}
+
+}

src/builder/java/speiger/src/builder/dependencies/IDependency.java

@@ -0,0 +1,104 @@
+package speiger.src.builder.dependencies;
+
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.function.Consumer;
+
+import com.google.gson.JsonElement;
+import com.google.gson.JsonObject;
+import com.google.gson.JsonPrimitive;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.Requirements.Requirement;
+
+@SuppressWarnings("javadoc")
+public interface IDependency {
+	
+	
+	public void set(Map<String, LoadingState> dependency);
+	public void set(ClassType key, ClassType value);
+	public LoadingState isLoaded(ClassType key, ClassType value);
+	public String getLocalStateKey(ClassType keyType, ClassType valueType);
+	public boolean isEnabled();
+	public boolean isLeaf();
+	public boolean isRoot();
+	
+	public String getName();
+	public void validateDependency(Consumer<String> result, ClassType keyType, ClassType valueType);
+	public void resolveRequirements(ClassType keyType, ClassType valueType);
+	
+	public void addChild(IDependency child);
+	public <T extends IDependency> T addDependency(Requirement require);
+	public default <T extends IDependency> T addKeyDependency(IDependency dependency) { return addDependency(new Requirement(dependency, Requirements.KEY_TEST, Requirements.KEY_GETTER)); }
+	public default <T extends IDependency> T addValueDependency(IDependency dependency) { return addDependency(new Requirement(dependency, Requirements.VALUE_TEST, Requirements.VALUE_GETTER)); }
+	public default <T extends IDependency> T addEntryDependency(IDependency dependency) { return addDependency(new Requirement(dependency, Requirements.ENTRY_TEST, Requirements.ENTRY_GETTER)); }
+	public default <T extends IDependency> T addTypeDependency(IDependency dependency, ClassType type) { return addDependency(new Requirement(dependency, Requirements.typedTest(type), Requirements.typedKey(type))); }
+	public default <T extends IDependency> T addOptionalTypeDependency(IDependency dependency, ClassType type, boolean key) { return addDependency(new Requirement(dependency, Requirements.optionalTest(type, key), Requirements.optionalKey(type, key))); }
+	public default <T extends IDependency> T addOptionalTypeDependency(ClassType type, boolean key) { return addDependency(new Requirement(this, Requirements.optionalTest(type, key), Requirements.optionalKey(type, key))); }
+
+	
+	public static void flatten(String prefix, boolean applyMiddle, JsonObject object, Map<String, LoadingState> result) {
+		if(applyMiddle) prefix+="-";
+		for(Entry<String, JsonElement> entry : object.entrySet()) {
+			String key = entry.getKey();
+			JsonElement value = entry.getValue();
+			if(value instanceof JsonPrimitive) {
+				String entryKey = prefix+key;
+				if("Enabled".equalsIgnoreCase(key)) {
+					entryKey = prefix.substring(0, prefix.length()-1);
+				}
+				result.put(entryKey, LoadingState.of(((JsonPrimitive)value).getAsBoolean()));
+			}
+			if(value instanceof JsonObject) {
+				flatten(prefix+key, true, (JsonObject)value, result);
+			}
+		}
+	}
+	
+	public static enum LoadingState {
+		OPTIONAL,
+		REQUIRED,
+		REJECTED;
+		
+		private static LoadingState RESOLVED = LoadingState.REQUIRED;
+		
+		public static LoadingState of(boolean value) {
+			return value ? REQUIRED : REJECTED;
+		}
+		
+		public LoadingState merge(LoadingState merge) {
+			return ordinal() > merge.ordinal() ? this : merge;
+		}
+		
+		public LoadingState replaceIfUndefined(LoadingState state) {
+			return this == OPTIONAL ? state : this;
+		}
+		
+		public LoadingState resolveIfUndefined() {
+			return this == OPTIONAL ? RESOLVED : this;
+		}
+		
+		public LoadingState mergeDown(LoadingState merge) {
+			if(merge == REJECTED || ordinal() > merge.ordinal()) {
+				return this;
+			}
+			return merge;
+		}
+		
+		public LoadingState mergeUp(LoadingState merge) {
+			if(merge == REQUIRED || ordinal() > merge.ordinal()) {
+				return this;
+			}
+			return merge;
+		}
+		
+		public static void setOptionalResolver(LoadingState state) {
+			RESOLVED = state;
+		}
+		
+		public boolean getJsonResult() {
+			LoadingState state = this == OPTIONAL ? RESOLVED : this;
+			return state == REQUIRED;
+		}
+	}
+}

src/builder/java/speiger/src/builder/dependencies/ModuleDependency.java

@@ -0,0 +1,31 @@
+package speiger.src.builder.dependencies;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.modules.BaseModule;
+
+@SuppressWarnings("javadoc")
+public class ModuleDependency extends BaseDependency {
+	BaseModule owner;
+	
+	public ModuleDependency(BaseModule owner, boolean biType) {
+		super(owner.getModuleName(), biType);
+		this.owner = owner;
+	}
+	
+	public FunctionDependency createDependency(String name) {
+		FunctionDependency result = new FunctionDependency(this, name);
+		if(biType) result.addEntryDependency(this);
+		else result.addKeyDependency(this);
+		return result;
+	}
+	
+	@Override
+	public LoadingState isLoaded(ClassType key, ClassType value) {
+		if(dependencies == null) return LoadingState.REQUIRED;
+		LoadingState result = getLocalState(key, value);
+		if(FETCH_FAILURES && result == LoadingState.REJECTED) {
+			FAILURE_KEYS.add(getLocalStateKey(key, value));
+		}
+		return result.replaceIfUndefined(getGlobalState()).resolveIfUndefined().merge(getReqirementState(key, value));
+	}
+}

src/builder/java/speiger/src/builder/dependencies/Requirements.java

@@ -0,0 +1,68 @@
+package speiger.src.builder.dependencies;
+
+import java.util.function.Consumer;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.IDependency.LoadingState;
+
+@SuppressWarnings("javadoc")
+public class Requirements {
+	public static final RequirementTest KEY_TEST = (T, K, V) -> T.isLoaded(K, K);
+	public static final RequirementTest VALUE_TEST = (T, K, V) -> T.isLoaded(V, V);
+	public static final RequirementTest ENTRY_TEST = (T, K, V) -> T.isLoaded(K, V);
+	
+	public static RequirementTest typedTest(ClassType type) {
+		return (T, K, V) -> T.isLoaded(type, type);
+	}
+	
+	public static RequirementTest optionalTest(ClassType type, boolean key) {
+		return (T, K, V) -> (key ? K : V) != type ? T.isLoaded(type, type) : LoadingState.REQUIRED;
+	}
+	
+	public static final RequirementKey KEY_GETTER = (T, K, V) -> T.getLocalStateKey(K, K);
+	public static final RequirementKey VALUE_GETTER = (T, K, V) -> T.getLocalStateKey(V, V);
+	public static final RequirementKey ENTRY_GETTER = (T, K, V) -> T.getLocalStateKey(K, V);
+	
+	public static RequirementKey typedKey(ClassType type) {
+		return (T, K, V) -> T.getLocalStateKey(type, type);
+	}
+	
+	public static RequirementKey optionalKey(ClassType type, boolean key) {
+		return (T, K, V) -> (key ? K : V) != type ? T.getLocalStateKey(type, type) : "";
+	}
+
+	
+	
+	public interface RequirementTest {
+		public LoadingState test(IDependency test, ClassType keyType, ClassType valueType);
+	}
+	
+	public static interface RequirementKey {
+		public String key(IDependency test, ClassType keyType, ClassType valueType);
+	}
+	
+	public static interface RequirementResolver {
+		public void resolve(IDependency test, Consumer<String> result, ClassType keyType, ClassType valueType);
+	}
+	
+	public static class Requirement {
+		IDependency dependency;
+		RequirementTest test;
+		RequirementKey key;
+		
+		public Requirement(IDependency dependency, RequirementTest test, RequirementKey key) {
+			this.dependency = dependency;
+			this.test = test;
+			this.key = key;
+		}
+		
+		public LoadingState test(ClassType keyType, ClassType valueType) {
+			return test.test(dependency, keyType, valueType);
+		}
+		
+		public String key(ClassType keyType, ClassType valueType) {
+			return key.key(dependency, keyType, valueType);
+		}
+		
+	}
+}

src/builder/java/speiger/src/builder/modules/AsyncModule.java

@@ -1,9 +1,17 @@
 package speiger.src.builder.modules;
 
+import java.util.Arrays;
+import java.util.List;
+
+import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
+
 @SuppressWarnings("javadoc")
 public class AsyncModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new AsyncModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(JavaModule.MODULE);
 	
 	@Override
 	public String getModuleName() { return "Async"; }
@@ -16,16 +24,16 @@ public class AsyncModule extends BaseModule
 	@Override
 	protected void loadFunctions() {}
 	@Override
-	public boolean areDependenciesLoaded() { return isDependencyLoaded(CollectionModule.INSTANCE); }
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE); }
 	@Override
 	protected void loadBlockades() {
-		if(!isModuleEnabled()) {
+		if(!MODULE.isEnabled()) {
 			addBlockedFiles("AsyncBuilder", "Task");
 		}
 	}
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) {
+		if(MODULE.isEnabled()) {
 			addKeyFlag("ASYNC_MODULE");
 		}
 	}

src/builder/java/speiger/src/builder/modules/BaseModule.java

@@ -1,13 +1,15 @@
 package speiger.src.builder.modules;
 
 import java.util.Collections;
-import java.util.Set;
+import java.util.List;
+import java.util.function.Consumer;
 import java.util.function.Predicate;
 
 import speiger.src.builder.ClassType;
 import speiger.src.builder.ModulePackage;
 import speiger.src.builder.RequiredType;
 import speiger.src.builder.SettingsManager;
+import speiger.src.builder.dependencies.IDependency;
 import speiger.src.builder.mappers.ArgumentMapper;
 import speiger.src.builder.mappers.InjectMapper;
 import speiger.src.builder.mappers.LineMapper;
@@ -30,6 +32,9 @@ public abstract class BaseModule
 		this.entry = entry;
 		keyType = entry.getKeyType();
 		valueType = entry.getValueType();
+		for(IDependency dependency : getDependencies(keyType, valueType)) {
+			dependency.set(keyType, valueType);
+		}
 		loadVariables();
 		loadClasses();
 		loadTestClasses();
@@ -56,32 +61,12 @@ public abstract class BaseModule
 	
 	public abstract String getModuleName();
 	public boolean isBiModule() { return false; }
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) { return Collections.emptySet(); }
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Collections.emptyList(); }
 	public boolean isModuleValid(ClassType keyType, ClassType valueType) { return true; }
 	
 	public ClassType keyType() { return keyType; }
 	public ClassType valueType() { return valueType; }
 	
-	protected boolean isModuleEnabled() {
-		return manager == null || manager.isModuleEnabled(this, keyType, valueType);
-	}
-	
-	protected boolean isModuleEnabled(String name) {
-		return manager == null || manager.isModuleEnabled(this, keyType, valueType, name);
-	}
-	
-	protected boolean isDependencyLoaded(BaseModule module) {
-		return isDependencyLoaded(module, true);
-	}
-	
-	protected boolean isDependencyLoaded(BaseModule module, boolean key) {
-		return manager == null || (module.isBiModule() ? manager.isModuleEnabled(module, keyType, valueType) : (key ? manager.isModuleEnabled(module, keyType, keyType) : manager.isModuleEnabled(module, valueType, valueType))); 
-	}
-	
-	public boolean areDependenciesLoaded() {
-		return true;
-	}
-	
 	protected void addFlag(String name) {
 		entry.addFlag(name);
 	}
@@ -205,4 +190,9 @@ public abstract class BaseModule
 		entry.addMapper(mapper);
 		return mapper;
 	}
+	
+	public static <T> T make(T input, Consumer<T> processor) {
+		processor.accept(input);
+		return input;
+	}
 }

src/builder/java/speiger/src/builder/modules/CollectionModule.java

@@ -1,52 +1,59 @@
 package speiger.src.builder.modules;
 
 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;
 
 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
 
 @SuppressWarnings("javadoc")
 public class CollectionModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new CollectionModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false)
+			.addKeyDependency(FunctionModule.MODULE)
+			.addOptionalTypeDependency(FunctionModule.MODULE, ClassType.OBJECT, true)
+			.addOptionalTypeDependency(FunctionModule.MODULE, ClassType.INT, true)
+			.addOptionalTypeDependency(ClassType.OBJECT, true);
+	public static final FunctionDependency STREAMS = MODULE.createDependency("Streams");
+	public static final FunctionDependency SPLIT_ITERATORS = MODULE.createDependency("Splititerators").addKeyDependency(STREAMS);
+	public static final FunctionDependency IARRAY = MODULE.createDependency("IArray");
+	public static final FunctionDependency STRATEGY = MODULE.createDependency("Strategy");
 	
 	@Override
 	public String getModuleName() { return "Collection"; }
 	@Override
 	protected void loadVariables() {}
 	@Override
-	public boolean areDependenciesLoaded(){ return isDependencyLoaded(JavaModule.INSTANCE); }
-	
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType)
-	{
-		return new TreeSet<>(Arrays.asList("Streams", "Splititerators", "IArray", "Strategy"));
-	}
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, STREAMS, SPLIT_ITERATORS, IARRAY, STRATEGY); }
 	
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) addKeyFlag("COLLECTION_MODULE");
-		if(isModuleEnabled("Streams")) addKeyFlag("STREAM_FEATURE");
-		if(isModuleEnabled("Splititerators")) addKeyFlag("SPLIT_ITERATOR_FEATURE");
-		if(isModuleEnabled("IArray")) addKeyFlag("IARRAY_FEATURE");
+		if(MODULE.isEnabled()) addKeyFlag("COLLECTION_MODULE");
+		if(STREAMS.isEnabled()) addKeyFlag("STREAM_FEATURE");
+		if(SPLIT_ITERATORS.isEnabled()) addKeyFlag("SPLIT_ITERATOR_FEATURE");
+		if(IARRAY.isEnabled()) addKeyFlag("IARRAY_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades() {
-		if(!isModuleEnabled()) {
+		if(!MODULE.isEnabled()) {
 			addBlockedFiles("Iterable", "Iterables", "Iterator", "Iterators", "BidirectionalIterator", "ListIterator");
-			addBlockedFiles("Arrays", "Collection", "AbstractCollection", "Collections", "Stack");
+			addBlockedFiles("Arrays", "Collection", "OrderedCollection", "AbstractCollection", "Collections", "Stack");
 		}
-		if(!isModuleEnabled("Splititerators")) addBlockedFiles("Splititerator", "Splititerators");
-		if(!isModuleEnabled("IArray")) addBlockedFiles("IArray");
-		if(!isModuleEnabled("Strategy")) addBlockedFiles("Strategy");
+		if(!SPLIT_ITERATORS.isEnabled()) addBlockedFiles("Splititerator", "Splititerators");
+		if(!IARRAY.isEnabled()) addBlockedFiles("IArray");
+		if(!STRATEGY.isEnabled()) addBlockedFiles("Strategy");
 		
-		if(keyType.isObject()) {
+		if(keyType.isObject())
+		{
 			addBlockedFiles("Stack");
 			addBlockedFiles("CollectionStreamTester");
 		}
-		if(keyType == ClassType.BOOLEAN) {
+		if(keyType == ClassType.BOOLEAN)
+		{
 			addBlockedFiles("CollectionRemoveIfTester", "CollectionStreamTester");
 			addBlockedFilter(T -> T.endsWith("Tester") && T.startsWith("Iterable"));
 		}
@@ -84,6 +91,7 @@ public class CollectionModule extends BaseModule
 	{
 		//Abstract Classes
 		addAbstractMapper("ABSTRACT_COLLECTION", "Abstract%sCollection");
+		addAbstractMapper("REVERSED_ORDERED_COLLECTION", "Reverse%sOrderedCollection");
 		
 		//Helper Classes
 		addClassMapper("ARRAYS", "Arrays");
@@ -94,6 +102,7 @@ public class CollectionModule extends BaseModule
 		
 		//Interfaces
 		addClassMapper("COLLECTION", "Collection");
+		addClassMapper("ORDERED_COLLECTION", "OrderedCollection");
 		addClassMapper("ITERABLE", "Iterable");
 		addClassMapper("SPLIT_ITERATOR", "Splititerator");
 		addClassMapper("LIST_ITERATOR", "ListIterator");

src/builder/java/speiger/src/builder/modules/FunctionModule.java

@@ -1,12 +1,18 @@
 package speiger.src.builder.modules;
 
+import java.util.Arrays;
+import java.util.List;
+
 import speiger.src.builder.ClassType;
 import speiger.src.builder.RequiredType;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
 
 @SuppressWarnings("javadoc")
 public class FunctionModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new FunctionModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(JavaModule.MODULE);
 	
 	@Override
 	public String getModuleName() { return "Function"; }
@@ -19,10 +25,17 @@ public class FunctionModule extends BaseModule
 	@Override
 	protected void loadTestClasses() {}
 	
+	@Override
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) {
+		return Arrays.asList(MODULE);
+	}
+	
 	@Override
 	protected void loadBlockades()
 	{
 		if(keyType.isObject()) addBlockedFiles("Consumer", "Comparator");
+		if(!MODULE.isEnabled()) addBlockedFiles("Consumer", "BiConsumer", "Comparator", "Supplier", "Optional", "Function", "UnaryOperator");
+		if(!keyType.needsCustomJDKType()) addBlockedFiles("Optional");
 	}
 	
 	@Override
@@ -48,6 +61,7 @@ public class FunctionModule extends BaseModule
 		}
 		else addBiRequirement("Function");
 		addRemapper("BiConsumer", "%sConsumer");
+		addRemapper("Optional", "Optional%s");
 	}
 	
 	@Override
@@ -82,6 +96,8 @@ public class FunctionModule extends BaseModule
 		
 		addFunctionMappers("PREDICATE", "%sPredicate");
 		addClassMapper("SUPPLIER", "Supplier");
+		addSimpleMapper("OPTIONAL", keyType.isObject() ? "Optional" : String.format("Optional%s", keyType.getFileType()));
+		addSimpleMapper("VALUE_OPTIONAL", valueType.isObject() ? "Optional" : String.format("Optional%s", valueType.getFileType()));
 		addAbstractMapper("SINGLE_UNARY_OPERATOR", "%1$s%1$sUnaryOperator");
 		addBiClassMapper("UNARY_OPERATOR", "UnaryOperator", "");
 		if(keyType.isObject())

src/builder/java/speiger/src/builder/modules/JavaModule.java

@@ -1,11 +1,17 @@
 package speiger.src.builder.modules;
 
+import java.util.Arrays;
+import java.util.List;
+
 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
 
 @SuppressWarnings("javadoc")
 public class JavaModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new JavaModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false);
 	
 	@Override
 	public String getModuleName() { return "Base"; }
@@ -17,6 +23,11 @@ public class JavaModule extends BaseModule
 		loadBaseVariables();
 	}
 	
+	@Override
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) {
+		return Arrays.asList(MODULE);
+	}
+	
 	@Override
 	protected void loadFlags()
 	{
@@ -49,6 +60,8 @@ public class JavaModule extends BaseModule
 		addSimpleMapper("APPLY_KEY_VALUE", keyType.isObject() ? "apply" : "applyAs"+keyType.getNonFileType());
 		addSimpleMapper("APPLY_VALUE", valueType.isObject() ? "apply" : "applyAs"+valueType.getNonFileType());
 		addSimpleMapper("APPLY_CAST", "applyAs"+keyType.getCustomJDKType().getNonFileType());
+		addSimpleMapper("GET_OPTIONAL", keyType.isObject() ? "ofNullable" : "of");
+		addSimpleMapper("GET_OPTIONAL_VALUE", valueType.isObject() ? "ofNullable" : "of");
 		
 		//Shared by Maps and Pairs so moved to java.
 		addFunctionMappers("ENTRY_KEY", "get%sKey");
@@ -185,6 +198,7 @@ public class JavaModule extends BaseModule
 		addComment("@Type", "@param <%s> the keyType of elements maintained by this Collection");
 		addValueComment("@ValueArrayType", "@param <%s> the keyType of array that the operation should be applied");
 		addValueComment("@ValueType", "@param <%s> the keyType of elements maintained by this Collection");
+		addSimpleMapper("@Java21", getVersion() >= 21 ? "@Override" : "");
 		addAnnontion("@PrimitiveOverride", "@Override");
 		addSimpleMapper("@PrimitiveDoc", "");
 		addAnnontion("@Primitive", "@Deprecated");

src/builder/java/speiger/src/builder/modules/ListModule.java

@@ -1,55 +1,57 @@
 package speiger.src.builder.modules;
 
 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;
 
 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
 
 @SuppressWarnings("javadoc")
 public class ListModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new ListModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(CollectionModule.MODULE).addKeyDependency(CollectionModule.SPLIT_ITERATORS);
+	public static final FunctionDependency IMPLEMENTATION = MODULE.createDependency("Implementations");
+	public static final FunctionDependency WRAPPERS = MODULE.createDependency("Wrappers");
+	public static final FunctionDependency ARRAY_LIST = MODULE.createDependency("ArrayList").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency LINKED_LIST = MODULE.createDependency("LinkedList").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency IMMUTABLE_LIST = MODULE.createDependency("ImmutableList").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency COPY_ON_WRITE_LIST = MODULE.createDependency("CopyOnWriteList").addKeyDependency(IMPLEMENTATION);
 	
 	@Override
 	public String getModuleName() { return "List"; }
 	@Override
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, IMPLEMENTATION, WRAPPERS, ARRAY_LIST, LINKED_LIST, IMMUTABLE_LIST, COPY_ON_WRITE_LIST); }
+	@Override
 	protected void loadVariables() {}
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) addKeyFlag("LIST_MODULE");
-		if(isModuleEnabled("Wrappers")) addKeyFlag("LISTS_FEATURE");
-		boolean implementations = isModuleEnabled("Implementations");
-		if(implementations && isModuleEnabled("ArrayList")) addKeyFlag("ARRAY_LIST_FEATURE");
-		if(implementations && isModuleEnabled("LinkedList")) addKeyFlag("LINKED_LIST_FEATURE");
-		if(implementations && isModuleEnabled("ImmutableList")) addKeyFlag("IMMUTABLE_LIST_FEATURE");
-		if(implementations && isModuleEnabled("CopyOnWriteList")) addKeyFlag("COPY_ON_WRITE_LIST_FEATURE");
+		if(MODULE.isEnabled()) addKeyFlag("LIST_MODULE");
+		if(WRAPPERS.isEnabled()) addKeyFlag("LISTS_FEATURE");
+		if(ARRAY_LIST.isEnabled()) addKeyFlag("ARRAY_LIST_FEATURE");
+		if(LINKED_LIST.isEnabled()) addKeyFlag("LINKED_LIST_FEATURE");
+		if(IMMUTABLE_LIST.isEnabled()) addKeyFlag("IMMUTABLE_LIST_FEATURE");
+		if(COPY_ON_WRITE_LIST.isEnabled()) addKeyFlag("COPY_ON_WRITE_LIST_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades()
 	{
-		if(!isModuleEnabled("Wrappers")) addBlockedFiles("Lists");
-		boolean implementations = !isModuleEnabled("Implementations");
-		if(implementations || !isModuleEnabled("ArrayList")) addBlockedFiles("ArrayList");
-		if(implementations || !isModuleEnabled("LinkedList")) addBlockedFiles("LinkedList");
-		if(implementations || !isModuleEnabled("ImmutableList")) addBlockedFiles("ImmutableList");
-		if(implementations || !isModuleEnabled("CopyOnWriteList")) addBlockedFiles("CopyOnWriteList");
-		if(!isModuleEnabled()) addBlockedFiles("List", "AbstractList");
+		if(!WRAPPERS.isEnabled()) addBlockedFiles("Lists");
+		if(!ARRAY_LIST.isEnabled()) addBlockedFiles("ArrayList");
+		if(!LINKED_LIST.isEnabled()) addBlockedFiles("LinkedList");
+		if(!IMMUTABLE_LIST.isEnabled()) addBlockedFiles("ImmutableList");
+		if(!COPY_ON_WRITE_LIST.isEnabled()) addBlockedFiles("CopyOnWriteList");
+		if(!MODULE.isEnabled()) addBlockedFiles("List", "AbstractList");
+		
 		
 		if(keyType.isObject()) addBlockedFiles("ListFillBufferTester");
 		if(keyType == ClassType.BOOLEAN) addBlockedFiles("ListFillBufferTester", "ListReplaceAllTester");
 	}
 	
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) {
-		return new TreeSet<>(Arrays.asList("Implementations", "Wrappers", "ArrayList", "LinkedList", "ImmutableList", "CopyOnWriteList"));
-	}
 
-	@Override
-	public boolean areDependenciesLoaded() {
-		return isDependencyLoaded(CollectionModule.INSTANCE);
-	}
 	
 	@Override
 	protected void loadRemappers()

src/builder/java/speiger/src/builder/modules/MapModule.java

@@ -1,15 +1,44 @@
 package speiger.src.builder.modules;
 
+import java.util.ArrayList;
 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;
 
 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
 
 @SuppressWarnings("javadoc")
 public class MapModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new MapModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, true)
+			.addKeyDependency(SetModule.MODULE)
+			.addValueDependency(CollectionModule.MODULE)
+			.addEntryDependency(SetModule.MODULE)
+			.addTypeDependency(SetModule.MODULE, ClassType.OBJECT);
+	public static final FunctionDependency IMPLEMENTATION = MODULE.createDependency("Implementations");
+	public static final FunctionDependency WRAPPERS = MODULE.createDependency("Wrappers").addKeyDependency(SetModule.WRAPPERS).addOptionalTypeDependency(SetModule.WRAPPERS, ClassType.OBJECT, true);
+
+	public static final FunctionDependency ORDERED_MAP = MODULE.createDependency("OrderedMap").addKeyDependency(SetModule.ORDERED_SET).addOptionalTypeDependency(SetModule.ORDERED_SET, ClassType.OBJECT, true);
+	public static final FunctionDependency SORTED_MAP = MODULE.createDependency("SortedMap").addKeyDependency(SetModule.SORTED_SET).addOptionalTypeDependency(SetModule.SORTED_SET, ClassType.OBJECT, true);
+
+	public static final FunctionDependency ARRAY_MAP = MODULE.createDependency("ArrayMap").addEntryDependency(ORDERED_MAP).addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency IMMUTABLE_MAP = MODULE.createDependency("ImmutableMap").addEntryDependency(IMPLEMENTATION);
+
+	public static final FunctionDependency HASH_MAP = MODULE.createDependency("HashMap").addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency LINKED_MAP = MODULE.createDependency("LinkedHashMap").addEntryDependency(HASH_MAP).addEntryDependency(ORDERED_MAP);
+	
+	public static final FunctionDependency CUSTOM_MAP = MODULE.createDependency("CustomHashMap").addEntryDependency(IMPLEMENTATION).addKeyDependency(CollectionModule.STRATEGY);
+	public static final FunctionDependency LINKED_CUSTOM_MAP = MODULE.createDependency("LinkedCustomHashMap").addEntryDependency(CUSTOM_MAP).addEntryDependency(ORDERED_MAP);
+
+	public static final FunctionDependency ENUM_MAP = MODULE.createDependency("EnumMap").addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency LINKED_ENUM_MAP = MODULE.createDependency("LinkedEnumMap").addEntryDependency(ENUM_MAP).addEntryDependency(ORDERED_MAP);
+	
+	public static final FunctionDependency CONCURRENT_MAP = MODULE.createDependency("ConcurrentMap").addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency AVL_TREE_MAP = MODULE.createDependency("AVLTreeMap").addEntryDependency(SORTED_MAP).addEntryDependency(IMPLEMENTATION);
+	public static final FunctionDependency RB_TREE_MAP = MODULE.createDependency("RBTreeMap").addEntryDependency(SORTED_MAP).addEntryDependency(IMPLEMENTATION);
 	
 	@Override
 	public String getModuleName() { return "Map"; }
@@ -20,79 +49,52 @@ public class MapModule extends BaseModule
 	@Override
 	public boolean isModuleValid(ClassType keyType, ClassType valueType) { return keyType != ClassType.BOOLEAN; }
 	@Override
-	public boolean areDependenciesLoaded() { return isDependencyLoaded(SetModule.INSTANCE) && isDependencyLoaded(CollectionModule.INSTANCE, false); }
-	
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) {
-		Set<String> sets = new TreeSet<>();
-		sets.addAll(Arrays.asList("Wrappers", "Implementations"));
-		sets.addAll(Arrays.asList("OrderedMap", "SortedMap"));
-		sets.addAll(Arrays.asList("ArrayMap", "ConcurrentMap", "ImmutableMap"));
-		sets.addAll(Arrays.asList("HashMap", "LinkedHashMap"));
-		sets.addAll(Arrays.asList("CustomHashMap", "LinkedCustomHashMap"));
-		sets.addAll(Arrays.asList("EnumMap", "LinkedEnumMap"));
-		sets.addAll(Arrays.asList("AVLTreeMap", "RBTreeMap"));
-		return sets;
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) {
+		List<IDependency> dependencies = new ArrayList<>(Arrays.asList(MODULE, ORDERED_MAP, SORTED_MAP, IMPLEMENTATION, WRAPPERS, ARRAY_MAP, IMMUTABLE_MAP, HASH_MAP, LINKED_MAP, CUSTOM_MAP, LINKED_CUSTOM_MAP, CONCURRENT_MAP, AVL_TREE_MAP, RB_TREE_MAP));
+		if(keyType == ClassType.OBJECT) dependencies.addAll(Arrays.asList(ENUM_MAP, LINKED_ENUM_MAP));
+		return dependencies;
 	}
 	
 	@Override
 	protected void loadFlags()
 	{
-		if(isModuleEnabled()) addFlag("MAP_MODULE");
-		if(isModuleEnabled("Wrappers")) addFlag("MAPS_FEATURE");
-		boolean implementations = isModuleEnabled("Implementations");
-		boolean hashMap = implementations && isModuleEnabled("HashMap");
-		boolean customHashMap = implementations && isModuleEnabled("CustomHashMap");
-		boolean enumMap = implementations && isModuleEnabled("EnumMap");
+		if(MODULE.isEnabled()) addFlag("MAP_MODULE");
+		if(WRAPPERS.isEnabled()) addFlag("MAPS_FEATURE");
+		if(ORDERED_MAP.isEnabled()) addFlag("ORDERED_MAP_FEATURE");
+		if(ARRAY_MAP.isEnabled()) addFlag("ARRAY_MAP_FEATURE");
+		if(LINKED_MAP.isEnabled()) addFlag("LINKED_MAP_FEATURE");
+		if(LINKED_CUSTOM_MAP.isEnabled()) addFlag("LINKED_CUSTOM_MAP_FEATURE");
+		if(LINKED_ENUM_MAP.isEnabled()) addFlag("LINKED_ENUM_MAP_FEATURE");
 		
-		if(isModuleEnabled("OrderedMap")) {
-			addFlag("ORDERED_MAP_FEATURE");
-			if(isModuleEnabled("ArrayMap")) addFlag("ARRAY_MAP_FEATURE");
-			if(hashMap && isModuleEnabled("LinkedHashMap")) addFlag("LINKED_MAP_FEATURE");
-			if(customHashMap && isModuleEnabled("LinkedCustomHashMap")) addFlag("LINKED_CUSTOM_MAP_FEATURE");
-			if(enumMap && isModuleEnabled("LinkedEnumMap")) addFlag("LINKED_ENUM_MAP_FEATURE");
-		}
-		if(isModuleEnabled("SortedMap")) {
-			addFlag("SORTED_MAP_FEATURE");
-			if(implementations && isModuleEnabled("AVLTreeMap")) addFlag("AVL_TREE_MAP_FEATURE");
-			if(implementations && isModuleEnabled("RBTreeMap")) addFlag("RB_TREE_MAP_FEATURE");
-		}
-		if(implementations && isModuleEnabled("ConcurrentMap")) addFlag("CONCURRENT_MAP_FEATURE");
-		if(implementations && isModuleEnabled("ImmutableMap")) addFlag("IMMUTABLE_MAP_FEATURE");
-		if(hashMap) addFlag("MAP_FEATURE");
-		if(customHashMap) addFlag("CUSTOM_MAP_FEATURE");
-		if(enumMap) addFlag("ENUM_MAP_FEATURE");
+		if(SORTED_MAP.isEnabled()) addFlag("SORTED_MAP_FEATURE");
+		if(AVL_TREE_MAP.isEnabled()) addFlag("AVL_TREE_MAP_FEATURE");
+		if(RB_TREE_MAP.isEnabled()) addFlag("RB_TREE_MAP_FEATURE");
+		
+		if(CONCURRENT_MAP.isEnabled()) addFlag("CONCURRENT_MAP_FEATURE");
+		if(IMMUTABLE_MAP.isEnabled()) addFlag("IMMUTABLE_MAP_FEATURE");
+		if(HASH_MAP.isEnabled()) addFlag("MAP_FEATURE");
+		if(CUSTOM_MAP.isEnabled()) addFlag("CUSTOM_MAP_FEATURE");
+		if(ENUM_MAP.isEnabled()) addFlag("ENUM_MAP_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades()
 	{
-		if(!isModuleEnabled()) addBlockedFiles("Map", "AbstractMap");
-		if(!isModuleEnabled("Wrappers")) addBlockedFiles("Maps");
-		boolean implementations = !isModuleEnabled("Implementations");
-		if(implementations || !isModuleEnabled("ImmutableMap")) addBlockedFiles("ImmutableOpenHashMap");
-		if(implementations || !isModuleEnabled("ConcurrentMap")) addBlockedFiles("ConcurrentMap", "ConcurrentOpenHashMap");
-		
-		boolean ordered = !isModuleEnabled("OrderedMap");
-		if(ordered) addBlockedFiles("OrderedMap");
-		boolean hashMap = implementations || !isModuleEnabled("HashMap");
-		if(hashMap) addBlockedFiles("OpenHashMap");
-		if(hashMap || ordered || !isModuleEnabled("LinkedHashMap")) addBlockedFiles("LinkedOpenHashMap");
-		
-		boolean customHashMap = implementations || !isModuleEnabled("CustomHashMap");
-		if(customHashMap) addBlockedFiles("OpenCustomHashMap");
-		if(customHashMap || ordered || !isModuleEnabled("LinkedCustomHashMap")) addBlockedFiles("LinkedOpenCustomHashMap");
-		
-		boolean enumMap = implementations || !isModuleEnabled("EnumMap");
-		if(enumMap) addBlockedFiles("EnumMap");
-		if(enumMap || ordered || !isModuleEnabled("LinkedEnumMap")) addBlockedFiles("LinkedEnumMap");
-		
-		if(ordered || !isModuleEnabled("ArrayMap")) addBlockedFiles("ArrayMap");
-		
-		boolean sorted = !isModuleEnabled("SortedMap");
-		if(sorted) addBlockedFiles("SortedMap", "NavigableMap");
-		if(implementations || sorted || !isModuleEnabled("AVLTreeMap")) addBlockedFiles("AVLTreeMap");
-		if(implementations || sorted || !isModuleEnabled("RBTreeMap")) addBlockedFiles("RBTreeMap");
+		if(!MODULE.isEnabled()) addBlockedFiles("Map", "AbstractMap");
+		if(!WRAPPERS.isEnabled()) addBlockedFiles("Maps");
+		if(!IMMUTABLE_MAP.isEnabled()) addBlockedFiles("ImmutableOpenHashMap");
+		if(!CONCURRENT_MAP.isEnabled()) addBlockedFiles("ConcurrentMap", "ConcurrentOpenHashMap");
+		if(!ORDERED_MAP.isEnabled()) addBlockedFiles("OrderedMap");
+		if(!HASH_MAP.isEnabled()) addBlockedFiles("OpenHashMap");
+		if(!LINKED_MAP.isEnabled()) addBlockedFiles("LinkedOpenHashMap");
+		if(!CUSTOM_MAP.isEnabled()) addBlockedFiles("OpenCustomHashMap");
+		if(!LINKED_CUSTOM_MAP.isEnabled()) addBlockedFiles("LinkedOpenCustomHashMap");
+		if(!ENUM_MAP.isEnabled()) addBlockedFiles("EnumMap");
+		if(!LINKED_ENUM_MAP.isEnabled()) addBlockedFiles("LinkedEnumMap");
+		if(!ARRAY_MAP.isEnabled()) addBlockedFiles("ArrayMap");
+		if(!SORTED_MAP.isEnabled()) addBlockedFiles("SortedMap", "NavigableMap");
+		if(!AVL_TREE_MAP.isEnabled()) addBlockedFiles("AVLTreeMap");
+		if(!RB_TREE_MAP.isEnabled()) addBlockedFiles("RBTreeMap");
 		
 		if(keyType == ClassType.BOOLEAN)
 		{
@@ -196,6 +198,7 @@ public class MapModule extends BaseModule
 		addBiRequirement("SortedMapNavigationTester");
 		addBiRequirement("OrderedMapNavigationTester");
 		addBiRequirement("OrderedMapMoveTester");
+		addBiRequirement("OrderedMapPutTester");
 		addBiRequirement("MapConstructorTester");
 		
 		addRemapper("TestMapGenerator", "Test%sMapGenerator");
@@ -251,6 +254,7 @@ public class MapModule extends BaseModule
 		
 		//Abstract Classes
 		addAbstractBiMapper("ABSTRACT_MAP", "Abstract%sMap", "2");
+		addAbstractBiMapper("REVERSED_ORDERED_MAP", "Reversed%sOrderedMap", "2");
 		
 		//Helper Classes
 		addBiClassMapper("MAPS", "Maps", "2");

src/builder/java/speiger/src/builder/modules/PairModule.java

@@ -1,15 +1,26 @@
 package speiger.src.builder.modules;
 
 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;
 
 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
 
 @SuppressWarnings("javadoc")
 public class PairModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new PairModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, true).addKeyDependency(JavaModule.MODULE);
+	public static final FunctionDependency IMMUTABLE = MODULE.createDependency("Immutable");
+	public static final FunctionDependency MUTABLE = MODULE.createDependency("Mutable");
+
+	
+//	public static final DependencyModule MODULE = new BiTypeModule(INSTANCE);
+//	public static final DependencyFunction IMMUTABLE = MODULE.createFunction("Immutable");
+//	public static final DependencyFunction MUTABLE = MODULE.createFunction("Mutable");
+	
 	@Override
 	public String getModuleName() { return "Pair"; }
 	@Override
@@ -21,20 +32,20 @@ public class PairModule extends BaseModule
 	@Override
 	protected void loadTestClasses() {}
 	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) { return new TreeSet<>(Arrays.asList("Mutable", "Immutable")); }
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, IMMUTABLE, MUTABLE); }
 	
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) addFlag("PAIR_MODULE");
-		if(isModuleEnabled("Mutable")) addFlag("MUTABLE_PAIR");
-		if(isModuleEnabled("Immutable")) addFlag("IMMUTABLE_PAIR");
+		if(MODULE.isEnabled()) addFlag("PAIR_MODULE");
+		if(MUTABLE.isEnabled()) addFlag("MUTABLE_PAIR");
+		if(IMMUTABLE.isEnabled()) addFlag("IMMUTABLE_PAIR");
 	}
 	
 	@Override
 	protected void loadBlockades() {
-		if(!isModuleEnabled()) addBlockedFiles("Pair");
-		if(!isModuleEnabled("Mutable")) addBlockedFiles("MutablePair");
-		if(!isModuleEnabled("Immutable")) addBlockedFiles("ImmutablePair");
+		if(!MODULE.isEnabled()) addBlockedFiles("Pair");
+		if(!MUTABLE.isEnabled()) addBlockedFiles("MutablePair");
+		if(!IMMUTABLE.isEnabled()) addBlockedFiles("ImmutablePair");
 	}
 	
 	@Override

src/builder/java/speiger/src/builder/modules/PrioQueueModule.java

@@ -1,15 +1,26 @@
 package speiger.src.builder.modules;
 
 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;
 
 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
 
 @SuppressWarnings("javadoc")
 public class PrioQueueModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new PrioQueueModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(CollectionModule.MODULE);
+	public static final FunctionDependency IMPLEMENTATION = MODULE.createDependency("Implementations");
+	public static final FunctionDependency WRAPPERS = MODULE.createDependency("Wrappers");
+	public static final FunctionDependency DEQUEUE = MODULE.createDependency("Dequeue");
+	
+	public static final FunctionDependency FIFO_QUEUE = MODULE.createDependency("FiFoQueue").addKeyDependency(DEQUEUE).addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency HEAP_QUEUE = MODULE.createDependency("HeapQueue").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency ARRAY_PRIO_QUEUE = MODULE.createDependency("ArrayPrioQueue").addKeyDependency(IMPLEMENTATION);
+	
 	
 	@Override
 	public String getModuleName() { return "PriorityQueue"; }
@@ -18,36 +29,26 @@ public class PrioQueueModule extends BaseModule
 	@Override
 	protected void loadFunctions() {}
 	@Override
-	public boolean areDependenciesLoaded() { return isDependencyLoaded(CollectionModule.INSTANCE); }
-	
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) {
-		return new TreeSet<>(Arrays.asList("Wrappers", "Implementations", "Dequeue", "FiFoQueue", "HeapQueue", "ArrayPrioQueue"));
-	}
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, WRAPPERS, IMPLEMENTATION, DEQUEUE, FIFO_QUEUE, HEAP_QUEUE, ARRAY_PRIO_QUEUE); }
 	
 	@Override
 	protected void loadFlags() {
-		if(isModuleEnabled()) addFlag("QUEUE_MODULE");
-		if(isModuleEnabled("Wrappers")) addKeyFlag("QUEUES_FEATURE");
-		boolean implementations = isModuleEnabled("Implementations");
-		if(isModuleEnabled("Dequeue")) {
-			addKeyFlag("DEQUEUE_FEATURE");
-			if(implementations && isModuleEnabled("FiFoQueue")) addKeyFlag("FIFO_QUEUE_FEATURE");
-		}
-		if(implementations && isModuleEnabled("HeapQueue")) addKeyFlag("HEAP_QUEUE_FEATURE");
-		if(implementations && isModuleEnabled("ArrayPrioQueue")) addKeyFlag("ARRAY_QUEUE_FEATURE");
+		if(MODULE.isEnabled()) addFlag("QUEUE_MODULE");
+		if(WRAPPERS.isEnabled()) addKeyFlag("QUEUES_FEATURE");
+		if(DEQUEUE.isEnabled()) addKeyFlag("DEQUEUE_FEATURE");
+		if(FIFO_QUEUE.isEnabled()) addKeyFlag("FIFO_QUEUE_FEATURE");
+		if(HEAP_QUEUE.isEnabled()) addKeyFlag("HEAP_QUEUE_FEATURE");
+		if(ARRAY_PRIO_QUEUE.isEnabled()) addKeyFlag("ARRAY_QUEUE_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades() {
-		if(!isModuleEnabled()) addBlockedFiles("PriorityQueue", "AbstractPriorityQueue");
-		if(!isModuleEnabled("Wrappers")) addBlockedFiles("PriorityQueues");
-		boolean implementations = !isModuleEnabled("Implementations");
-		boolean dequeue = !isModuleEnabled("Dequeue");
-		if(dequeue) addBlockedFiles("PriorityDequeue"); 
-		if(dequeue || implementations || !isModuleEnabled("FiFoQueue")) addBlockedFiles("ArrayFIFOQueue");
-		if(implementations || !isModuleEnabled("HeapQueue")) addBlockedFiles("HeapPriorityQueue");
-		if(implementations || !isModuleEnabled("ArrayPrioQueue")) addBlockedFiles("ArrayPriorityQueue");
+		if(!MODULE.isEnabled()) addBlockedFiles("PriorityQueue", "AbstractPriorityQueue");
+		if(!WRAPPERS.isEnabled()) addBlockedFiles("PriorityQueues");
+		if(!DEQUEUE.isEnabled()) addBlockedFiles("PriorityDequeue");
+		if(!FIFO_QUEUE.isEnabled()) addBlockedFiles("ArrayFIFOQueue");
+		if(!HEAP_QUEUE.isEnabled()) addBlockedFiles("HeapPriorityQueue");
+		if(!ARRAY_PRIO_QUEUE.isEnabled()) addBlockedFiles("ArrayPriorityQueue");
 		
 		if(keyType == ClassType.BOOLEAN) {
 			addBlockedFiles("QueueTests");

src/builder/java/speiger/src/builder/modules/SetModule.java

@@ -1,15 +1,30 @@
 package speiger.src.builder.modules;
 
 import java.util.Arrays;
-import java.util.Set;
-import java.util.TreeSet;
+import java.util.List;
 
 import speiger.src.builder.ClassType;
+import speiger.src.builder.dependencies.FunctionDependency;
+import speiger.src.builder.dependencies.IDependency;
+import speiger.src.builder.dependencies.ModuleDependency;
 
 @SuppressWarnings("javadoc")
 public class SetModule extends BaseModule
 {
 	public static final BaseModule INSTANCE = new SetModule();
+	public static final ModuleDependency MODULE = new ModuleDependency(INSTANCE, false).addKeyDependency(CollectionModule.MODULE).addKeyDependency(CollectionModule.SPLIT_ITERATORS);
+	public static final FunctionDependency IMPLEMENTATION = MODULE.createDependency("Implementations");
+	public static final FunctionDependency WRAPPERS = MODULE.createDependency("Wrappers");
+	public static final FunctionDependency ORDERED_SET = MODULE.createDependency("OrderedSet");
+	public static final FunctionDependency SORTED_SET = MODULE.createDependency("SortedSet");
+	public static final FunctionDependency ARRAY_SET = MODULE.createDependency("ArraySet").addKeyDependency(ORDERED_SET).addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency IMMUTABLE_SET = MODULE.createDependency("ImmutableSet").addKeyDependency(ORDERED_SET).addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency HASH_SET = MODULE.createDependency("HashSet").addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency LINKED_SET = MODULE.createDependency("LinkedHashSet").addKeyDependency(ORDERED_SET).addKeyDependency(HASH_SET);
+	public static final FunctionDependency CUSTOM_SET = MODULE.createDependency("CustomHashSet").addKeyDependency(IMPLEMENTATION).addKeyDependency(CollectionModule.STRATEGY);
+	public static final FunctionDependency LINKED_CUSTOM_SET = MODULE.createDependency("LinkedCustomHashSet").addKeyDependency(ORDERED_SET).addKeyDependency(CUSTOM_SET);
+	public static final FunctionDependency AVL_TREE_SET = MODULE.createDependency("AVLTreeSet").addKeyDependency(SORTED_SET).addKeyDependency(IMPLEMENTATION);
+	public static final FunctionDependency RB_TREE_SET = MODULE.createDependency("RBTreeSet").addKeyDependency(SORTED_SET).addKeyDependency(IMPLEMENTATION);
 	
 	@Override
 	public String getModuleName() { return "Set"; }
@@ -19,68 +34,40 @@ public class SetModule extends BaseModule
 	@Override
 	public boolean isModuleValid(ClassType keyType, ClassType valueType) { return keyType != ClassType.BOOLEAN; }
 	@Override
-	public boolean areDependenciesLoaded() { return isDependencyLoaded(CollectionModule.INSTANCE); }
-	@Override
-	public Set<String> getModuleKeys(ClassType keyType, ClassType valueType) {
-		Set<String> sets = new TreeSet<>();
-		sets.addAll(Arrays.asList("Wrappers", "Implementations"));
-		sets.addAll(Arrays.asList("OrderedSet", "SortedSet"));
-		sets.addAll(Arrays.asList("ArraySet", "ImmutableSet"));
-		sets.addAll(Arrays.asList("HashSet", "LinkedHashSet"));
-		sets.addAll(Arrays.asList("CustomHashSet", "LinkedCustomHashSet"));
-		sets.addAll(Arrays.asList("AVLTreeSet", "RBTreeSet"));
-		return sets;
-	}
+	public List<IDependency> getDependencies(ClassType keyType, ClassType valueType) { return Arrays.asList(MODULE, WRAPPERS, ORDERED_SET, SORTED_SET, IMPLEMENTATION, ARRAY_SET, IMMUTABLE_SET, HASH_SET, LINKED_SET, CUSTOM_SET, LINKED_CUSTOM_SET, AVL_TREE_SET, RB_TREE_SET); }
 	
 	@Override
 	protected void loadFlags()
 	{
-		if(isModuleEnabled()) addFlag("SET_MODULE");
-		if(isModuleEnabled("Wrappers")) addFlag("SETS_FEATURE");
-		boolean implementations = isModuleEnabled("Implementations");
-		boolean hashSet = implementations && isModuleEnabled("HashSet");
-		boolean customHashSet = implementations && isModuleEnabled("CustomHashSet");
-		
-		if(isModuleEnabled("OrderedSet")) {
-			addFlag("ORDERED_SET_FEATURE");
-			if(implementations && isModuleEnabled("ArraySet")) addFlag("ARRAY_SET_FEATURE");
-			if(hashSet && isModuleEnabled("LinkedHashSet")) addFlag("LINKED_SET_FEATURE");
-			if(customHashSet && isModuleEnabled("LinkedCustomHashSet")) addFlag("LINKED_CUSTOM_SET_FEATURE");
-		}
-		if(isModuleEnabled("SortedSet")) {
-			addFlag("SORTED_SET_FEATURE");
-			if(implementations && isModuleEnabled("AVLTreeSet")) addFlag("AVL_TREE_SET_FEATURE");
-			if(implementations && isModuleEnabled("RBTreeSet")) addFlag("RB_TREE_SET_FEATURE");
-		}
-		if(implementations && isModuleEnabled("ImmutableSet")) addFlag("IMMUTABLE_SET_FEATURE");
-		if(hashSet) addFlag("HASH_SET_FEATURE");
-		if(customHashSet) addFlag("CUSTOM_HASH_SET_FEATURE");
+		if(MODULE.isEnabled()) addFlag("SET_MODULE");
+		if(WRAPPERS.isEnabled()) addFlag("SETS_FEATURE");
+		if(ORDERED_SET.isEnabled()) addFlag("ORDERED_SET_FEATURE");
+		if(SORTED_SET.isEnabled()) addFlag("SORTED_SET_FEATURE");
+		if(IMMUTABLE_SET.isEnabled()) addFlag("IMMUTABLE_SET_FEATURE");
+		if(ARRAY_SET.isEnabled()) addFlag("ARRAY_SET_FEATURE");
+		if(HASH_SET.isEnabled()) addFlag("HASH_SET_FEATURE");
+		if(LINKED_SET.isEnabled()) addFlag("LINKED_SET_FEATURE");
+		if(CUSTOM_SET.isEnabled()) addFlag("CUSTOM_HASH_SET_FEATURE");
+		if(LINKED_CUSTOM_SET.isEnabled()) addFlag("LINKED_CUSTOM_SET_FEATURE");
+		if(AVL_TREE_SET.isEnabled()) addFlag("AVL_TREE_SET_FEATURE");
+		if(RB_TREE_SET.isEnabled()) addFlag("RB_TREE_SET_FEATURE");
 	}
 	
 	@Override
 	protected void loadBlockades()
 	{
-		if(!isModuleEnabled()) addBlockedFiles("Set", "AbstractSet");
-		if(!isModuleEnabled("Wrappers")) addBlockedFiles("Sets");
-		boolean implementations = !isModuleEnabled("Implementations");
-		if(implementations || !isModuleEnabled("ImmutableSet")) addBlockedFiles("ImmutableOpenHashSet");
-		
-		boolean ordered = !isModuleEnabled("OrderedSet");
-		if(ordered) addBlockedFiles("OrderedSet");
-		boolean hashSet = implementations || !isModuleEnabled("HashSet");
-		if(hashSet) addBlockedFiles("OpenHashSet");
-		if(hashSet || ordered || !isModuleEnabled("LinkedHashSet")) addBlockedFiles("LinkedOpenHashSet");
-		
-		boolean customHashSet = implementations || !isModuleEnabled("CustomHashSet");
-		if(customHashSet) addBlockedFiles("OpenCustomHashSet");
-		if(customHashSet || ordered || !isModuleEnabled("LinkedCustomHashSet")) addBlockedFiles("LinkedOpenCustomHashSet");
-		
-		if(implementations || ordered || !isModuleEnabled("ArraySet")) addBlockedFiles("ArraySet");
-		
-		boolean sorted = !isModuleEnabled("SortedSet");
-		if(sorted) addBlockedFiles("SortedSet", "NavigableSet");
-		if(implementations || sorted || !isModuleEnabled("AVLTreeSet")) addBlockedFiles("AVLTreeSet");
-		if(implementations || sorted || !isModuleEnabled("RBTreeSet")) addBlockedFiles("RBTreeSet");
+		if(!MODULE.isEnabled()) addBlockedFiles("Set", "AbstractSet");
+		if(!WRAPPERS.isEnabled()) addBlockedFiles("Sets");
+		if(!IMMUTABLE_SET.isEnabled()) addBlockedFiles("ImmutableOpenHashSet");
+		if(!ORDERED_SET.isEnabled()) addBlockedFiles("OrderedSet");
+		if(!HASH_SET.isEnabled()) addBlockedFiles("OpenHashSet");
+		if(!LINKED_SET.isEnabled()) addBlockedFiles("LinkedOpenHashSet");
+		if(!CUSTOM_SET.isEnabled()) addBlockedFiles("OpenCustomHashSet");
+		if(!LINKED_CUSTOM_SET.isEnabled()) addBlockedFiles("LinkedOpenCustomHashSet");
+		if(!ARRAY_SET.isEnabled()) addBlockedFiles("ArraySet");
+		if(!SORTED_SET.isEnabled()) addBlockedFiles("SortedSet", "NavigableSet");
+		if(!AVL_TREE_SET.isEnabled()) addBlockedFiles("AVLTreeSet");
+		if(!RB_TREE_SET.isEnabled()) addBlockedFiles("RBTreeSet");
 		
 		if(keyType == ClassType.BOOLEAN)
 		{
@@ -161,6 +148,7 @@ public class SetModule extends BaseModule
 		
 		//Abstract Classes
 		addAbstractMapper("ABSTRACT_SET", "Abstract%sSet");
+		addAbstractMapper("REVERSED_ORDERED_SET", "Reversed%sOrderedSet");
 		
 		//Helper Classes
 		addClassMapper("SETS", "Sets");

src/builder/resources/speiger/assets/collections/templates/collections/AbstractCollection.template

@@ -1,12 +1,18 @@
 package speiger.src.collections.PACKAGE.collections;
 
 import java.util.Collection;
+#if ORDERED_MAP_FEATURE
+import java.util.function.Supplier;
+#endif
 import java.util.Objects;
 import java.util.AbstractCollection;
 #if TYPE_OBJECT
 import java.util.function.Consumer;
 #endif
 
+#if ORDERED_MAP_FEATURE
+import speiger.src.collections.PACKAGE.lists.LIST_ITERATOR;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 import speiger.src.collections.PACKAGE.utils.ITERATORS;
@@ -262,5 +268,79 @@ public abstract class ABSTRACT_COLLECTION KEY_GENERIC_TYPE extends AbstractColle
 		if (a.length > size()) a[size()] = EMPTY_KEY_VALUE;
 		return a;
 	}
+
+#endif
+#if ORDERED_MAP_FEATURE
+	public static class REVERSED_ORDERED_COLLECTION KEY_GENERIC_TYPE extends ABSTRACT_COLLECTION KEY_GENERIC_TYPE implements ORDERED_COLLECTION KEY_GENERIC_TYPE {
+		ORDERED_COLLECTION KEY_GENERIC_TYPE collection;
+		Supplier<ITERATOR KEY_GENERIC_TYPE> reverseIterator;
+		
+		public REVERSED_ORDERED_COLLECTION(ORDERED_COLLECTION KEY_GENERIC_TYPE collection, Supplier<ITERATOR KEY_GENERIC_TYPE> reverseIterator) {
+			this.collection = collection;
+			this.reverseIterator = reverseIterator;
+		}
+		
+		@Override
+		public boolean add(KEY_TYPE o) { return collection.add(o); }
+		@Override
+		public ORDERED_COLLECTION KEY_GENERIC_TYPE reversed() { return collection; }
+		@Override
+		public void addFirst(KEY_TYPE e) { collection.addLast(e); }
+		@Override
+		public void addLast(KEY_TYPE e) { collection.addFirst(e); }
+		@Override
+#if !TYPE_OBJECT
+		public boolean contains(KEY_TYPE e) { return collection.contains(e); }
+#else
+		public boolean contains(Object e) { return collection.contains(e); }
+#endif
+		@Override
+#if !TYPE_OBJECT
+		public boolean REMOVE_KEY(KEY_TYPE e) { return collection.REMOVE_KEY(e); }
+#else
+		public boolean remove(Object e) { return collection.remove(e); }
+#endif
+		@Override
+		public void clear() { collection.clear(); }
+		@Override
+		public KEY_TYPE GET_FIRST_KEY() { return collection.GET_LAST_KEY(); }
+		@Override
+		public KEY_TYPE REMOVE_FIRST_KEY() { return collection.REMOVE_LAST_KEY(); }
+		@Override
+		public KEY_TYPE GET_LAST_KEY() { return collection.GET_FIRST_KEY(); }
+		@Override
+		public KEY_TYPE REMOVE_LAST_KEY() { return collection.REMOVE_FIRST_KEY(); }
+		@Override
+		public ITERATOR KEY_GENERIC_TYPE iterator() { return reverseIterator.get(); }
+		@Override
+		public int size() { return collection.size(); }
+	}
+	
+	public static class ReverseBiIterator KEY_GENERIC_TYPE implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		LIST_ITERATOR KEY_GENERIC_TYPE it;
+		
+		public ReverseBiIterator(LIST_ITERATOR KEY_GENERIC_TYPE it) {
+			this.it = it;
+		}
+		
+		@Override
+		public KEY_TYPE NEXT() { return it.PREVIOUS(); }
+		@Override
+		public boolean hasNext() { return it.hasPrevious(); }
+		@Override
+		public boolean hasPrevious() { return it.hasNext(); }
+		@Override
+		public KEY_TYPE PREVIOUS() { return it.NEXT(); }
+		@Override
+		public void remove() { it.remove(); }
+		@Override
+		public int nextIndex() { return it.previousIndex(); }
+		@Override
+		public int previousIndex() { return it.nextIndex(); }
+		@Override
+		public void set(KEY_TYPE e) { it.set(e); }
+		@Override
+		public void add(KEY_TYPE e) { it.add(e); }
+	}
 #endif
 }

src/builder/resources/speiger/assets/collections/templates/collections/BidirectionalIterator.template

@@ -1,19 +1,11 @@
 package speiger.src.collections.PACKAGE.collections;
 
-#if !TYPE_OBJECT
-import speiger.src.collections.objects.collections.ObjectBidirectionalIterator;
-/**
- * A Type-Specific {@link ObjectBidirectionalIterator} to reduce (un)boxing
- */
-public interface BI_ITERATOR KEY_GENERIC_TYPE extends ITERATOR KEY_GENERIC_TYPE, ObjectBidirectionalIterator<CLASS_TYPE>
-#else
 /**
  * This is a basically a {@link java.util.ListIterator} without the index functions.
  * Allowing to have a simple Bidirectional Iterator without having to keep track of the Iteration index.
  * @Type(T)
  */
 public interface BI_ITERATOR KEY_GENERIC_TYPE extends ITERATOR KEY_GENERIC_TYPE
-#endif
 {
 	/**
 	 * Returns true if the Iterator has a Previous element
@@ -29,11 +21,11 @@ public interface BI_ITERATOR KEY_GENERIC_TYPE extends ITERATOR KEY_GENERIC_TYPE
 	public KEY_TYPE PREVIOUS();
 	
 #if !TYPE_OBJECT
-	/** {@inheritDoc}
+	/**
 	 * <p>This default implementation delegates to the corresponding type-specific function.
 	 * @deprecated Please use the corresponding type-specific function instead. 
+	 * @return the Previous element of the iterator.+
 	 */
-	@Override
 	@Deprecated
 	public default CLASS_TYPE previous() {
 		return KEY_TO_OBJ(PREVIOUS());

src/builder/resources/speiger/assets/collections/templates/collections/Iterable.template

@@ -5,6 +5,9 @@ import java.util.function.Consumer;
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
+#if JDK_TYPE 
+import java.util.OPTIONAL;
+#endif
 
 #if !TYPE_OBJECT
 
@@ -30,6 +33,9 @@ import speiger.src.collections.PACKAGE.collections.OUTPUT_ITERABLE;
 #endif
 #enditerate
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.PACKAGE.functions.function.TO_OBJECT_FUNCTION;
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
@@ -408,13 +414,13 @@ public interface ITERABLE KEY_GENERIC_TYPE extends Iterable<CLASS_TYPE>
 	 * @param filter that should be applied
 	 * @return the found value or the null equivalent variant.
 	 */
-	default KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	default OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(ITERATOR KEY_GENERIC_TYPE iter = iterator();iter.hasNext();) {
 			KEY_TYPE entry = iter.NEXT();
-			if(filter.test(entry)) return entry;
+			if(filter.test(entry)) return OPTIONAL.GET_OPTIONAL(entry);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -459,7 +465,7 @@ public interface ITERABLE KEY_GENERIC_TYPE extends Iterable<CLASS_TYPE>
 	 * @param operator the operation that should be applied
 	 * @return the reduction result, returns null value if nothing was found
 	 */
-	default KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	default OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -471,7 +477,7 @@ public interface ITERABLE KEY_GENERIC_TYPE extends Iterable<CLASS_TYPE>
 			}
 			state = operator.APPLY_VALUE(state, iter.NEXT());
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}	
 	
 	/**

src/builder/resources/speiger/assets/collections/templates/collections/OrderedCollection.template

@@ -0,0 +1,83 @@
+package speiger.src.collections.PACKAGE.collections;
+
+#if JAVA_VERSION>=21
+import java.util.SequencedCollection;
+
+public interface ORDERED_COLLECTION KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, SequencedCollection<CLASS_TYPE> {
+#else
+public interface ORDERED_COLLECTION KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE {
+#endif
+	@Java21
+	ORDERED_COLLECTION KEY_GENERIC_TYPE reversed();
+	
+	/**
+	 * A method to add an element to the start of a collection
+	 * @param e that should be added at the start.
+	 */
+	public void addFirst(KEY_TYPE e);
+	
+	/**
+	 * A method to add an element to the end of a collection
+	 * @param e that should be added at the end.
+	 */
+	public void addLast(KEY_TYPE e);
+	
+	/**
+	 * A method to get the first element in the collection
+	 * @return first element in the collection
+	 */
+	public KEY_TYPE GET_FIRST_KEY();
+	/**
+	 * A method to get and remove the first element in the collection
+	 * @return first element in the collection
+	 */
+	public KEY_TYPE REMOVE_FIRST_KEY();
+	/**
+	 * A method to get the last element in the collection
+	 * @return last element in the collection
+	 */
+	public KEY_TYPE GET_LAST_KEY();
+	/**
+	 * A method to get and remove the last element in the collection
+	 * @return last element in the collection
+	 */
+	public KEY_TYPE REMOVE_LAST_KEY();
+	
+#if JAVA_VERSION>=21 && !TYPE_OBJECT
+	@Override
+	@Deprecated
+	default void addFirst(CLASS_TYPE e) {
+		addFirst(OBJ_TO_KEY(e));
+	}
+	
+	@Override
+	@Deprecated
+	default void addLast(CLASS_TYPE e) {
+		addLast(OBJ_TO_KEY(e));
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE getFirst() {
+		return KEY_TO_OBJ(GET_FIRST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE getLast() {
+		return KEY_TO_OBJ(GET_LAST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeFirst() {
+		return KEY_TO_OBJ(REMOVE_FIRST_KEY());
+	}
+
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeLast() {
+		return KEY_TO_OBJ(REMOVE_LAST_KEY());
+	}
+#endif
+}

src/builder/resources/speiger/assets/collections/templates/functions/Optional.template

@@ -0,0 +1,89 @@
+package speiger.src.collections.PACKAGE.functions;
+
+import java.util.NoSuchElementException;
+import java.util.function.Supplier;
+
+public final class OPTIONAL KEY_GENERIC_TYPE {
+	private static final OPTIONAL NO_GENERIC_TYPE EMPTY = new OPTIONALBRACES();
+	
+	private final boolean isPresent;
+	private final KEY_TYPE value;
+	
+	private OPTIONAL() {
+		this.isPresent = false;
+		this.value = EMPTY_VALUE;
+	}
+	
+	private OPTIONAL(KEY_TYPE value) {
+		this.isPresent = true;
+		this.value = value;
+	}
+	
+	public static OPTIONAL KEY_GENERIC_TYPE empty() {
+		return EMPTY;
+	}
+	
+	public static OPTIONAL KEY_GENERIC_TYPE of(KEY_TYPE value) {
+		return new OPTIONALBRACES(value);
+	}
+	
+	public KEY_TYPE SUPPLY_GET() {
+		if(!isPresent) throw new NoSuchElementException("No value present");
+		return value;
+	}
+	
+	public boolean isPresent() {
+		return isPresent;
+	}
+	
+	public boolean isEmpty() {
+		return !isPresent;
+	}
+	
+	public void ifPresent(CONSUMER KEY_GENERIC_TYPE consumer) {
+		if(isPresent) consumer.accept(value);
+	}
+	
+    public void ifPresentOrElse(CONSUMER KEY_GENERIC_TYPE action, Runnable emptyAction) {
+        if (isPresent) action.accept(value);
+        else emptyAction.run();
+    }
+	
+	public KEY_TYPE orElse(KEY_TYPE other) {
+		return isPresent ? value : other;
+	}
+	
+	public KEY_TYPE orElseGet(SUPPLIER KEY_GENERIC_TYPE other) {
+		return isPresent ? value : other.SUPPLY_GET();
+	}
+	
+	public KEY_TYPE orElseThrow() {
+        if (!isPresent) throw new NoSuchElementException("No value present");
+		return value;
+	}
+	
+    public <X extends Throwable> KEY_TYPE orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
+    	if(isPresent) return value;
+    	else throw exceptionSupplier.get();
+    }
+    
+    @Override
+    public boolean equals(Object obj) {
+    	if(obj == this) return true;
+    	if(obj instanceof OPTIONAL) {
+    		OPTIONAL KEY_GENERIC_TYPE other = (OPTIONAL KEY_GENERIC_TYPE)obj;
+    		return (isPresent && other.isPresent ? KEY_EQUALS(value, other.value) : isPresent == other.isPresent);
+    	}
+    	return false;
+    }
+    
+    @Override
+    public int hashCode() {
+    	return isPresent ? KEY_TO_HASH(value) : 0;
+    }
+    
+    @Override
+    public String toString() {
+    	return isPresent ? "OPTIONAL["+value+"]" : "OPTIONAL.empty";
+    }
+}

src/builder/resources/speiger/assets/collections/templates/lists/AbstractList.template

@@ -11,11 +11,15 @@ import java.util.RandomAccess;
 import speiger.src.collections.PACKAGE.collections.ABSTRACT_COLLECTION;
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+#endif
 #if INT_LIST_MODULE && !TYPE_INT
 import speiger.src.collections.ints.lists.IntList;
 #endif
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 import speiger.src.collections.utils.SanityChecks;
 
 /**
@@ -532,9 +536,10 @@ public abstract class ABSTRACT_LIST KEY_GENERIC_TYPE extends ABSTRACT_COLLECTION
 		public int size() {
 			return size;
 		}
-		
+#if SPLIT_ITERATOR_FEATURE
 		@Override
 		public SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 16464); }
+#endif
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE listIterator(int index) {

src/builder/resources/speiger/assets/collections/templates/lists/ArrayList.template

@@ -7,6 +7,9 @@ import java.util.Comparator;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if TYPE_OBJECT
 #if IARRAY_FEATURE || TYPE_OBJECT
 import java.util.function.Consumer;
@@ -33,6 +36,9 @@ import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.STACK;
 #endif
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -682,12 +688,12 @@ public class ARRAY_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0;i<size;i++) {
-			if(filter.test(data[i])) return data[i];
+			if(filter.test(data[i])) return OPTIONAL.GET_OPTIONAL(data[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -714,7 +720,7 @@ public class ARRAY_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -726,7 +732,7 @@ public class ARRAY_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 			}
 			state = operator.APPLY_VALUE(state, data[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override

src/builder/resources/speiger/assets/collections/templates/lists/CopyOnWriteList.template

@@ -8,6 +8,9 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 import java.util.concurrent.locks.ReentrantLock;
 import java.util.function.Consumer;
 import java.util.function.Supplier;
@@ -33,6 +36,9 @@ import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.STACK;
 #endif
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -535,7 +541,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	 * @return if the element was found.
 	 */
 	@Override
-	@Deprecated
+	@Primitive
 	public boolean contains(Object o) {
 		return indexOf(o) != -1;
 	}
@@ -546,7 +552,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	 * @return the index of the element if found. (if not found then -1)
 	 */
 	@Override
-	@Deprecated
+	@Primitive
 	public int indexOf(Object o) {
 		KEY_TYPE[] data = this.data;
 #if TYPE_OBJECT
@@ -570,7 +576,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	 * @return the last index of the element if found. (if not found then -1)
 	 */
 	@Override
-	@Deprecated
+	@Primitive
 	public int lastIndexOf(Object o) {
 		KEY_TYPE[] data = this.data;
 #if TYPE_OBJECT
@@ -810,13 +816,13 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		KEY_TYPE[] data = this.data;
 		for(int i = 0,m=data.length;i<m;i++) {
-			if(filter.test(data[i])) return data[i];
+			if(filter.test(data[i])) return OPTIONAL.GET_OPTIONAL(data[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -845,7 +851,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE[] data = this.data;
 		KEY_TYPE state = EMPTY_VALUE;
@@ -858,7 +864,7 @@ public class COPY_ON_WRITE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENER
 			}
 			state = operator.APPLY_VALUE(state, data[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override

src/builder/resources/speiger/assets/collections/templates/lists/ImmutableList.template

@@ -7,6 +7,9 @@ import java.util.Comparator;
 import java.util.Collection;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if TYPE_OBJECT
 import java.util.function.BiFunction;
 import java.util.function.Consumer;
@@ -27,6 +30,9 @@ import speiger.src.collections.PACKAGE.collections.COLLECTION;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.PACKAGE.utils.ARRAYS;
 #endif
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
@@ -335,12 +341,12 @@ public class IMMUTABLE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_T
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0,m=data.length;i<m;i++) {
-			if(filter.test(data[i])) return data[i];
+			if(filter.test(data[i])) return OPTIONAL.GET_OPTIONAL(data[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -367,7 +373,7 @@ public class IMMUTABLE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_T
 
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -379,7 +385,7 @@ public class IMMUTABLE_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_T
 			}
 			state = operator.APPLY_VALUE(state, data[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override

src/builder/resources/speiger/assets/collections/templates/lists/LinkedList.template

@@ -4,7 +4,6 @@ package speiger.src.collections.PACKAGE.lists;
 #if DEQUEUE_FEATURE
 import java.util.Comparator;
 #endif
-
 import java.util.function.BiFunction;
 #else if PRIMITIVES
 import java.nio.JAVA_BUFFER;
@@ -12,12 +11,17 @@ import java.nio.JAVA_BUFFER;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 import java.util.NoSuchElementException;
+#if SPLIT_ITERATOR_FEATURE
 import java.util.Spliterator;
 #if PRIMITIVES
 import java.util.Spliterator.JAVA_SPLIT_ITERATOR;
 #endif
 import java.util.function.Consumer;
+#endif
 import java.util.function.Predicate;
 #if TYPE_OBJECT
 import java.util.function.IntFunction;
@@ -32,6 +36,9 @@ import java.util.function.JAVA_PREDICATE;
 #endif
 import java.util.function.JAVA_UNARY_OPERATOR;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -60,12 +67,14 @@ import speiger.src.collections.objects.utils.ObjectArrays;
 #if TYPE_OBJECT
 import speiger.src.collections.utils.Stack;
 #endif
+#if SPLIT_ITERATOR_FEATURE
 #if PRIMITIVES
 import java.util.stream.JAVA_STREAM;
 import java.util.stream.StreamSupport;
 #endif
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
 import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 import speiger.src.collections.utils.SanityChecks;
 
 /**
@@ -416,6 +425,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 		return new ListIter(getNode(index), index);
 	}
 
+#if SPLIT_ITERATOR_FEATURE
 #if PRIMITIVES
 	/**
 	 * Returns a Java-Type-Specific Stream to reduce boxing/unboxing.
@@ -436,6 +446,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	@Override
 	public SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return new TypeSplitIteratorBRACES(this, first, 0); }
 	
+#endif
 	@Override
 	public void forEach(CONSUMER KEY_SUPER_GENERIC_TYPE action) {
 		Objects.requireNonNull(action);
@@ -487,12 +498,12 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(Entry KEY_GENERIC_TYPE entry = first;entry != null;entry = entry.next) {
-			if(filter.test(entry.value)) return entry.value;
+			if(filter.test(entry.value)) return OPTIONAL.GET_OPTIONAL(entry.value);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -519,7 +530,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -531,7 +542,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 			}
 			state = operator.APPLY_VALUE(state, entry.value);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -1253,6 +1264,7 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 		}
 	}
 	
+#if SPLIT_ITERATOR_FEATURE
 	private static class TypeSplitIterator KEY_GENERIC_TYPE implements SPLIT_ITERATOR KEY_GENERIC_TYPE 
 	{
 		static final int BATCH_UNIT = 1 << 10;
@@ -1397,4 +1409,5 @@ public class LINKED_LIST KEY_GENERIC_TYPE extends ABSTRACT_LIST KEY_GENERIC_TYPE
 		}
 	}
 #endif
+#endif
 }

src/builder/resources/speiger/assets/collections/templates/lists/List.template

@@ -15,7 +15,10 @@ import java.util.function.UnaryOperator;
 #endif
 
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
+import speiger.src.collections.PACKAGE.collections.ORDERED_COLLECTION;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
@@ -27,7 +30,9 @@ import speiger.src.collections.PACKAGE.utils.LISTS;
 #if INT_LIST_MODULE && !TYPE_INT
 import speiger.src.collections.ints.lists.IntList;
 #endif
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 #if TYPE_BYTE || TYPE_SHORT || TYPE_CHAR || TYPE_FLOAT
 import speiger.src.collections.utils.SanityChecks;
 #endif
@@ -36,7 +41,7 @@ import speiger.src.collections.utils.SanityChecks;
  * A Type Specific List interface that reduces boxing/unboxing and adds a couple extra quality of life features
  * @Type(T)
  */
-public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List<CLASS_TYPE>
+public interface LIST KEY_GENERIC_TYPE extends ORDERED_COLLECTION KEY_GENERIC_TYPE, List<CLASS_TYPE>
 {
 #if !TYPE_OBJECT
 	/**
@@ -101,6 +106,24 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	 */
 	public boolean addAll(int index, LIST KEY_GENERIC_TYPE c);
 	
+	/**
+	 * A method to add an element to the start of a list
+	 * @param e that should be added at the start.
+	 */
+	@Override
+	public default void addFirst(KEY_TYPE e) { 
+		add(0, e);
+	}
+	
+	/**
+	 * A method to add an element to the end of a list
+	 * @param e that should be added at the end.
+	 */
+	@Override
+	public default void addLast(KEY_TYPE e) {
+		add(e);
+	}
+	
 	/**
 	 * Helper method that returns the first element of a List.
 	 * This function was introduced due to how annoying it is to get/remove the last element of a list.
@@ -504,9 +527,56 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	@Override
 	@Deprecated
 	public default boolean add(CLASS_TYPE e) {
-		return COLLECTION.super.add(e);
+		return ORDERED_COLLECTION.super.add(e);
 	}
 
+#if JAVA_VERSION>=21
+#if !TYPE_OBJECT
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void addFirst(CLASS_TYPE e) {
+		addFirst(OBJ_TO_KEY(e));
+	}
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void addLast(CLASS_TYPE e) {
+		addLast(OBJ_TO_KEY(e));
+	}
+	
+#endif
+	@Override
+	@Deprecated
+	default CLASS_TYPE getFirst() {
+		return KEY_TO_OBJ(GET_FIRST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE getLast() {
+		return KEY_TO_OBJ(GET_LAST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeFirst() {
+		return KEY_TO_OBJ(REMOVE_FIRST_KEY());
+	}
+	
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeLast() {
+		return KEY_TO_OBJ(REMOVE_LAST_KEY());
+	}
+	
+#endif
 	/** {@inheritDoc}
 	 * <p>This default implementation delegates to the corresponding type-specific function.
 	 * @deprecated Please use the corresponding type-specific function instead. 
@@ -554,7 +624,7 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	@Override
 	@Deprecated
 	public default boolean contains(Object o) {
-		return COLLECTION.super.contains(o);
+		return ORDERED_COLLECTION.super.contains(o);
 	}
 	
 	/** {@inheritDoc}
@@ -564,7 +634,7 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	@Override
 	@Deprecated
 	public default boolean remove(Object o) {
-		return COLLECTION.super.remove(o);
+		return ORDERED_COLLECTION.super.remove(o);
 	}
 	
 	/** {@inheritDoc}
@@ -594,10 +664,12 @@ public interface LIST KEY_GENERIC_TYPE extends COLLECTION KEY_GENERIC_TYPE, List
 	}
 #endif
 #endif
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
 	 */
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
+#endif
 }

src/builder/resources/speiger/assets/collections/templates/maps/abstracts/AbstractMap.template

@@ -14,6 +14,15 @@ import speiger.src.collections.PACKAGE.functions.function.FUNCTION;
 #endif
 import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
+#if ORDERED_MAP_FEATURE
+import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
+import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
+#if !TYPE_OBJECT
+import speiger.src.collections.objects.sets.AbstractObjectSet;
+import speiger.src.collections.objects.sets.ObjectOrderedSet;
+#endif
+#endif
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.SET;
 #if MAPS_FEATURE
@@ -42,7 +51,7 @@ import speiger.src.collections.utils.SanityChecks;
  */
 public abstract class ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE extends AbstractMap<CLASS_TYPE, CLASS_VALUE_TYPE> implements MAP KEY_VALUE_GENERIC_TYPE
 {
-	protected VALUE_TYPE defaultReturnValue = EMPTY_VALUE;
+	protected VALUE_TYPE defaultReturnValue = INVALID_VALUE;
 	
 	@Override
 	public VALUE_TYPE getDefaultReturnValue() {
@@ -119,7 +128,7 @@ public abstract class ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE extends AbstractMap<CL
 	public void putAll(CLASS_TYPE[] keys, CLASS_VALUE_TYPE[] values, int offset, int size) {
 		SanityChecks.checkArrayCapacity(keys.length, offset, size);
 		SanityChecks.checkArrayCapacity(values.length, offset, size);
-		for(int i = 0;i<size;i++) put(keys[i], values[i]);		
+		for(int i = 0;i<size;i++) put(OBJ_TO_KEY(keys[i]), OBJ_TO_VALUE(values[i]));		
 	}
 	
 #endif
@@ -543,6 +552,132 @@ public abstract class ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE extends AbstractMap<CL
 		return hash;
 	}
 	
+	public static class REVERSED_ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE implements ORDERED_MAP KEY_VALUE_GENERIC_TYPE {
+		ORDERED_MAP KEY_VALUE_GENERIC_TYPE map;
+		
+		public REVERSED_ORDERED_MAP(ORDERED_MAP KEY_VALUE_GENERIC_TYPE map) {
+			this.map = map;
+		}
+		@Override
+		public ABSTRACT_MAP KEY_VALUE_GENERIC_TYPE setDefaultReturnValue(VALUE_TYPE v) {
+			map.setDefaultReturnValue(v);
+			return this;
+		}
+		@Override
+		public VALUE_TYPE getDefaultReturnValue() { return map.getDefaultReturnValue(); }
+		@Override
+		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE copy() { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE put(KEY_TYPE key, VALUE_TYPE value) { return map.put(key, value); }
+		@Override
+		public VALUE_TYPE putIfAbsent(KEY_TYPE key, VALUE_TYPE value) { return map.putIfAbsent(key, value); }
+#if VALUE_PRIMITIVES
+		@Override
+		public VALUE_TYPE addTo(KEY_TYPE key, VALUE_TYPE value) { return map.addTo(key, value); }
+		@Override
+		public VALUE_TYPE subFrom(KEY_TYPE key, VALUE_TYPE value) { return map.subFrom(key, value); }
+#endif
+		@Override
+		public VALUE_TYPE REMOVE_VALUE(KEY_TYPE key) { return map.REMOVE_VALUE(key); }
+#if !TYPE_OBJECT || !VALUE_OBJECT
+		@Override
+		public boolean remove(KEY_TYPE key, VALUE_TYPE value) { return map.remove(key, value); }
+#endif
+		@Override
+		public VALUE_TYPE REMOVE_VALUEOrDefault(KEY_TYPE key, VALUE_TYPE defaultValue) { return map.REMOVE_VALUEOrDefault(key, defaultValue); }
+		@Override
+#if TYPE_OBJECT
+		public boolean containsKey(Object key) { return map.containsKey(key); }
+#else
+		public boolean containsKey(KEY_TYPE key) { return map.containsKey(key); }
+#endif
+		@Override
+#if VALUE_OBJECT
+		public boolean containsValue(Object value) { return map.containsValue(value); }
+#else
+		public boolean containsValue(VALUE_TYPE value) { return map.containsValue(value); }
+#endif
+		@Override
+		public boolean replace(KEY_TYPE key, VALUE_TYPE oldValue, VALUE_TYPE newValue) { return map.replace(key, oldValue, newValue); }
+		@Override
+		public VALUE_TYPE replace(KEY_TYPE key, VALUE_TYPE value) { return map.replace(key, value); }
+		@Override
+		public void REPLACE_VALUES(MAP KEY_VALUE_GENERIC_TYPE m) { map.REPLACE_VALUES(m); }
+		@Override
+		public void REPLACE_VALUES(UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { map.REPLACE_VALUES(mappingFunction); }
+		@Override
+		public VALUE_TYPE COMPUTE(KEY_TYPE key, UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE(key, mappingFunction); }
+		@Override
+		public VALUE_TYPE COMPUTE_IF_ABSENT(KEY_TYPE key, FUNCTION KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE_IF_ABSENT(key, mappingFunction); }
+		@Override
+		public VALUE_TYPE SUPPLY_IF_ABSENT(KEY_TYPE key, VALUE_SUPPLIER VALUE_GENERIC_TYPE valueProvider) { return map.SUPPLY_IF_ABSENT(key, valueProvider); }
+		@Override
+		public VALUE_TYPE COMPUTE_IF_PRESENT(KEY_TYPE key, UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE_IF_PRESENT(key, mappingFunction); }
+#if !VALUE_OBJECT
+		@Override
+		public VALUE_TYPE COMPUTENonDefault(KEY_TYPE key, UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTENonDefault(key, mappingFunction); }
+		@Override
+		public VALUE_TYPE COMPUTE_IF_ABSENTNonDefault(KEY_TYPE key, FUNCTION KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE_IF_ABSENTNonDefault(key, mappingFunction); }
+		@Override
+		public VALUE_TYPE SUPPLY_IF_ABSENTNonDefault(KEY_TYPE key, VALUE_SUPPLIER VALUE_GENERIC_TYPE valueProvider) { return map.SUPPLY_IF_ABSENTNonDefault(key, valueProvider); }
+		@Override
+		public VALUE_TYPE COMPUTE_IF_PRESENTNonDefault(KEY_TYPE key, UNARY_OPERATOR KEY_VALUE_GENERIC_TYPE mappingFunction) { return map.COMPUTE_IF_PRESENTNonDefault(key, mappingFunction); }
+#endif
+		@Override
+		public VALUE_TYPE MERGE(KEY_TYPE key, VALUE_TYPE value, VALUE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE mappingFunction) { return map.MERGE(key, value, mappingFunction); }
+#if !TYPE_OBJECT || !VALUE_OBJECT
+		@Override
+		public VALUE_TYPE getOrDefault(KEY_TYPE key, VALUE_TYPE defaultValue) { return map.getOrDefault(key, defaultValue); }
+#endif
+		@Override
+		public VALUE_TYPE GET_VALUE(KEY_TYPE key) { return map.GET_VALUE(key); }
+		@Override
+		public VALUE_TYPE putAndMoveToFirst(KEY_TYPE key, VALUE_TYPE value) { return map.putAndMoveToLast(key, value); }
+		@Override
+		public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value) { return map.putAndMoveToFirst(key, value); }
+		@Override
+		public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) { return map.putLast(key, value); }
+		@Override
+		public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) { return map.putFirst(key, value); }
+		@Override
+		public boolean moveToFirst(KEY_TYPE key) { return map.moveToLast(key); }
+		@Override
+		public boolean moveToLast(KEY_TYPE key) { return map.moveToFirst(key); }
+		@Override
+		public VALUE_TYPE getAndMoveToFirst(KEY_TYPE key) { return map.getAndMoveToLast(key); }
+		@Override
+		public VALUE_TYPE getAndMoveToLast(KEY_TYPE key) { return map.getAndMoveToFirst(key); }
+		@Override
+		public KEY_TYPE FIRST_ENTRY_KEY() { return map.LAST_ENTRY_KEY(); }
+		@Override
+		public KEY_TYPE POLL_FIRST_ENTRY_KEY() { return map.POLL_LAST_ENTRY_KEY(); }
+		@Override
+		public KEY_TYPE LAST_ENTRY_KEY() { return map.FIRST_ENTRY_KEY(); }
+		@Override
+		public KEY_TYPE POLL_LAST_ENTRY_KEY() { return map.POLL_FIRST_ENTRY_KEY(); }
+		@Override
+		public VALUE_TYPE FIRST_ENTRY_VALUE() { return map.LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE LAST_ENTRY_VALUE() { return map.FIRST_ENTRY_VALUE(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() { return map.lastEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() { return map.firstEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() { return map.pollLastEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() { return map.pollFirstEntry(); }
+		@Override
+		public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() { return new AbstractObjectSet.ReversedObjectOrderedSet<>(map.ENTRY_SET()); }
+		@Override
+		public ORDERED_SET KEY_GENERIC_TYPE keySet() { return new ABSTRACT_SET.REVERSED_ORDERED_SETBRACES(map.keySet()); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() { return map.values().reversed(); }
+		@Override
+		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE reversed() { return map; }
+	}
+
+	
 	/**
 	 * A Simple Type Specific Entry class to reduce boxing/unboxing
 	 * @Type(T)

src/builder/resources/speiger/assets/collections/templates/maps/impl/concurrent/ConcurrentOpenHashMap.template

@@ -4,15 +4,18 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.concurrent.locks.StampedLock;
 import java.util.function.Consumer;
 import java.util.function.Predicate;
 import java.util.function.BiFunction;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif
 
 #if !TYPE_OBJECT
@@ -40,9 +43,12 @@ import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if!VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.CONCURRENT_MAP;
@@ -78,6 +84,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if VALUE_OBJECT
@@ -839,7 +846,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -863,11 +870,11 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
 			MapEntry entry = new MapEntry();
 			for(int i = 0,m=segments.length;i<m;i++) {
@@ -877,7 +884,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 				try {
 					while(index != -1) {
 						entry.set(index, i);
-						if(filter.test(entry)) return entry;
+						if(filter.test(entry)) return Optional.ofNullable(entry);
 						index = (int)seg.links[index];
 					}
 				}
@@ -885,7 +892,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -1186,7 +1193,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1210,11 +1217,11 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(int i = 0,m=segments.length;i<m;i++) {
 				Segment KEY_VALUE_GENERIC_TYPE seg = segments[i];
@@ -1222,7 +1229,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 				try {
 					int index = seg.firstIndex;
 					while(index != -1){
-						if(filter.test(seg.keys[index])) return seg.keys[index];
+						if(filter.test(seg.keys[index])) return OPTIONAL.GET_OPTIONAL(seg.keys[index]);
 						index = (int)seg.links[index];
 					}
 				}
@@ -1230,7 +1237,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1454,7 +1461,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1478,20 +1485,20 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
 			for(int i = 0,m=segments.length;i<m;i++) {
 				Segment KEY_VALUE_GENERIC_TYPE seg = segments[i];
 				long stamp = seg.readLock();
 				try {
 					int index = seg.firstIndex;
 					while(index != -1){
-						if(filter.test(seg.values[index])) return seg.values[index];
+						if(filter.test(seg.values[index])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(seg.values[index]);
 						index = (int)seg.links[index];
 					}
 				}
@@ -1499,7 +1506,7 @@ public class CONCURRENT_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY
 					seg.unlockRead(stamp);
 				}
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override

src/builder/resources/speiger/assets/collections/templates/maps/impl/customHash/LinkedOpenCustomHashMap.template

@@ -4,14 +4,17 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif
 
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
@@ -27,6 +30,7 @@ import speiger.src.collections.ints.functions.consumer.IntObjectConsumer;
 import speiger.src.collections.ints.functions.consumer.VALUE_BI_FROM_INT_CONSUMER;
 #endif
 #if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
 #if !TYPE_INT || !SAME_TYPE
@@ -40,7 +44,7 @@ import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 import speiger.src.collections.PACKAGE.utils.STRATEGY;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_UNARY_OPERATOR;
@@ -59,6 +63,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT
@@ -295,6 +300,54 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		return getDefaultReturnValue();
 	}
 	
+	@Override
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) {
+		if(strategy.equals(key, EMPTY_KEY_VALUE)) {
+			if(containsNull) return values[nullIndex];
+			values[nullIndex] = value;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToFirstIndex(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(strategy.hashCode(key)) & mask;
+			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
+				if(strategy.equals(keys[pos], key)) return values[pos];
+				pos = ++pos & mask;
+			}
+			keys[pos] = key;
+			values[pos] = value;
+			onNodeAdded(pos);
+			moveToFirstIndex(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+		return getDefaultReturnValue();
+	}
+	
+	@Override
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) {
+		if(strategy.equals(key, EMPTY_KEY_VALUE)) {
+			if(containsNull) return values[nullIndex];
+			values[nullIndex] = value;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToLastIndex(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(strategy.hashCode(key)) & mask;
+			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
+				if(strategy.equals(keys[pos], key)) return values[pos];
+				pos = ++pos & mask;
+			}
+			keys[pos] = key;
+			values[pos] = value;
+			onNodeAdded(pos);
+			moveToLastIndex(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+		return getDefaultReturnValue();
+	}
+	
 	@Override
 	public boolean moveToFirst(KEY_TYPE key) {
 		if(isEmpty() || strategy.equals(FIRST_ENTRY_KEY(), key)) return false;
@@ -430,6 +483,52 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		return values[lastIndex];
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[firstIndex], values[firstIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[lastIndex], values[lastIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = firstIndex;
+		onNodeRemoved(pos);
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		if(strategy.equals(result.ENTRY_KEY(), EMPTY_KEY_VALUE)) {
+			containsNull = false;
+			keys[nullIndex] = EMPTY_KEY_VALUE;
+			values[nullIndex] = EMPTY_VALUE;
+		}
+		else shiftKeys(pos);
+		if(nullIndex > minCapacity && size < maxFill / 4 && nullIndex > HashUtil.DEFAULT_MIN_CAPACITY) rehash(nullIndex / 2);
+		return result;
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = lastIndex;
+		onNodeRemoved(pos);
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		if(strategy.equals(result.ENTRY_KEY(), EMPTY_KEY_VALUE)) {
+			containsNull = false;
+			keys[nullIndex] = EMPTY_KEY_VALUE;
+			values[nullIndex] = EMPTY_VALUE;
+		}
+		else shiftKeys(pos);
+		if(nullIndex > minCapacity && size < maxFill / 4 && nullIndex > HashUtil.DEFAULT_MIN_CAPACITY) rehash(nullIndex / 2);
+		return result;
+	}
+	
 	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 		if(entrySet == null) entrySet = new MapEntrySet();
@@ -443,9 +542,9 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	}
 	
 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
-		return valuesC;
+		return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)valuesC;
 	}
 	
 	@Override
@@ -614,6 +713,10 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -630,24 +733,24 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 			POLL_FIRST_ENTRY_KEY();
 			return entry;
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 			POLL_LAST_ENTRY_KEY();
 			return entry;
@@ -655,7 +758,12 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -665,7 +773,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -774,7 +882,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -789,21 +897,21 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 				state = operator.apply(state, new ValueMapEntry(index));
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			int index = firstIndex;
 			while(index != -1) {
 				entry.set(index);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 				index = (int)links[index];
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -901,9 +1009,12 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 			throw new UnsupportedOperationException();
 		}
 
+		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }		
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
-
 		@Override
 		public boolean addAndMoveToLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 
@@ -919,7 +1030,12 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-			return new KeyIterator();
+			return new KeyIterator(true);
+		}
+		
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return new KeyIterator(false);
 		}
 		
 		@Override
@@ -941,22 +1057,22 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 		
 		@Override
-		public KEY_TYPE FIRST_KEY() {
+		public KEY_TYPE GET_FIRST_KEY() {
 			return FIRST_ENTRY_KEY();
 		}
 		
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() {
+		public KEY_TYPE REMOVE_FIRST_KEY() {
 			return POLL_FIRST_ENTRY_KEY();
 		}
 
 		@Override
-		public KEY_TYPE LAST_KEY() {
+		public KEY_TYPE GET_LAST_KEY() {
 			return LAST_ENTRY_KEY();
 		}
 
 		@Override
-		public KEY_TYPE POLL_LAST_KEY() {
+		public KEY_TYPE REMOVE_LAST_KEY() {
 			return POLL_LAST_ENTRY_KEY();
 		}
 		
@@ -1056,7 +1172,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1071,19 +1187,19 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 				state = operator.APPLY_KEY_VALUE(state, keys[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
+			if(size() <= 0) return OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(keys[index])) return keys[index];
+				if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1100,39 +1216,47 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
 		@Deprecated
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
-		
+		public boolean contains(Object e) { return containsValue(e); }
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
-		
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return LINKED_CUSTOM_HASH_MAP.this.size();
-		}
-		
+		public int size() { return LINKED_CUSTOM_HASH_MAP.this.size(); }
 		@Override
-		public void clear() {
-			LINKED_CUSTOM_HASH_MAP.this.clear();
+		public void clear() { LINKED_CUSTOM_HASH_MAP.this.clear(); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() {
+			VALUE_TYPE result = FIRST_ENTRY_VALUE();
+			POLL_FIRST_ENTRY_KEY();
+			return result; 
+		}
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() {
+			VALUE_TYPE result = LAST_ENTRY_VALUE();
+			POLL_LAST_ENTRY_KEY();
+			return result; 
 		}
 		
 		@Override
@@ -1231,7 +1355,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1246,19 +1370,19 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 				state = operator.APPLY_VALUE(state, values[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(values[index])) return values[index];
+				if(filter.test(values[index])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1278,7 +1402,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
+		public FastEntryIterator(boolean start) { super(start); }
 		public FastEntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1305,7 +1429,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry;
 		
-		public EntryIterator() {}
+		public EntryIterator(boolean start) { super(start); }
 		public EntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1335,7 +1459,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
 		
-		public KeyIterator() {}
+		public KeyIterator(boolean start) { super(start); }
 		public KeyIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1357,7 +1481,7 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
-		public ValueIterator() {}
+		public ValueIterator(boolean start) { super(start); }
 		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
@@ -1378,16 +1502,20 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
 		int index = 0;
 		
-		MapIterator() {
-			next = firstIndex;
+		MapIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		MapIterator(KEY_TYPE from) {
+			this.forward = true;
 			if(strategy.equals(from, EMPTY_KEY_VALUE)) {
 				if(containsNull) {
 					next = (int) links[nullIndex];
@@ -1415,11 +1543,11 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		}
 		
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}
 
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		public int nextIndex() {
@@ -1479,20 +1607,30 @@ public class LINKED_CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends CUSTOM_HASH_M
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = previous;
-			previous = (int)(links[current] >> 32);
-			next = current;
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return current;
 		}
 		
 		public int nextEntry() {
 			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) moveForwards();
+			else moveBackwards();
+			if(index >= 0) index++;
+			return current;
+		}
+		
+		private void moveBackwards() {
+			current = previous;
+			previous = (int)(links[current] >> 32);
+			next = current;
+		}
+		
+		private void moveForwards() {
 			current = next;
 			next = (int)(links[current]);
 			previous = current;
-			if(index >= 0) index++;
-			return current;
 		}
 		
 		private void ensureIndexKnown() {

src/builder/resources/speiger/assets/collections/templates/maps/impl/customHash/OpenCustomHashMap.template

@@ -5,14 +5,17 @@ import java.util.ConcurrentModificationException;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif
 
 #if !TYPE_OBJECT
@@ -37,9 +40,12 @@ import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if !VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
 #if !TYPE_OBJECT
@@ -75,6 +81,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 import speiger.src.collections.objects.collections.ObjectIterator;
@@ -1090,7 +1097,7 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -1107,25 +1114,25 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 				}
 				state = operator.apply(state, new ValueMapEntry(i));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			if(containsNull) {
 				entry.set(nullIndex);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 			}
 			for(int i = nullIndex-1;i>=0;i--) {
 				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE)) {
 					entry.set(i);
-					if(filter.test(entry)) return entry;
+					if(filter.test(entry)) return Optional.ofNullable(entry);
 				}
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -1331,7 +1338,7 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1348,18 +1355,18 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 				}
 				state = operator.APPLY_KEY_VALUE(state, keys[i]);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
-			if(containsNull && filter.test(keys[nullIndex])) return keys[nullIndex];
+			if(size() <= 0) return OPTIONAL.empty();
+			if(containsNull && filter.test(keys[nullIndex])) return OPTIONAL.GET_OPTIONAL(keys[nullIndex]);
 			for(int i = nullIndex-1;i>=0;i--) {
-				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(keys[i])) return keys[i];
+				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1497,7 +1504,7 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1514,18 +1521,18 @@ public class CUSTOM_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VAL
 				}
 				state = operator.APPLY_VALUE(state, values[i]);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
-			if(containsNull && filter.test(values[nullIndex])) return values[nullIndex];
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
+			if(containsNull && filter.test(values[nullIndex])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[nullIndex]);
 			for(int i = nullIndex-1;i>=0;i--) {
-				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(values[i])) return values[i];
+				if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(values[i])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[i]);
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override

src/builder/resources/speiger/assets/collections/templates/maps/impl/hash/LinkedOpenHashMap.template

@@ -4,14 +4,17 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif
 
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
@@ -27,6 +30,7 @@ import speiger.src.collections.ints.functions.consumer.IntObjectConsumer;
 import speiger.src.collections.ints.functions.consumer.VALUE_BI_FROM_INT_CONSUMER;
 #endif
 #if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
 #if !TYPE_INT || !SAME_TYPE
@@ -39,7 +43,7 @@ import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_UNARY_OPERATOR;
@@ -58,6 +62,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT
@@ -272,6 +277,54 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		return getDefaultReturnValue();
 	}
 	
+	@Override
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) {
+		if(KEY_EQUALS_NULL(key)) {
+			if(containsNull) return values[nullIndex];
+			values[nullIndex] = value;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToFirstIndex(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(KEY_TO_HASH(key)) & mask;
+			while(KEY_EQUALS_NULL(key)) {
+				if(KEY_EQUALS(keys[pos], key)) return values[pos];
+				pos = ++pos & mask;
+			}
+			keys[pos] = key;
+			values[pos] = value;
+			onNodeAdded(pos);
+			moveToFirstIndex(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+		return getDefaultReturnValue();
+	}
+	
+	@Override
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) {
+		if(KEY_EQUALS_NULL(key)) {
+			if(containsNull) return values[nullIndex];
+			values[nullIndex] = value;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToLastIndex(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(KEY_TO_HASH(key)) & mask;
+			while(KEY_EQUALS_NULL(key)) {
+				if(KEY_EQUALS(keys[pos], key)) return values[pos];
+				pos = ++pos & mask;
+			}
+			keys[pos] = key;
+			values[pos] = value;
+			onNodeAdded(pos);
+			moveToLastIndex(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+		return getDefaultReturnValue();
+	}
+	
 	@Override
 	public boolean moveToFirst(KEY_TYPE key) {
 		if(isEmpty() || KEY_EQUALS(FIRST_ENTRY_KEY(), key)) return false;
@@ -434,6 +487,52 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		return values[lastIndex];
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[firstIndex], values[firstIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[lastIndex], values[lastIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = firstIndex;
+		onNodeRemoved(pos);
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		if(KEY_EQUALS_NULL(result.ENTRY_KEY())) {
+			containsNull = false;
+			keys[nullIndex] = EMPTY_KEY_VALUE;
+			values[nullIndex] = EMPTY_VALUE;
+		}
+		else shiftKeys(pos);
+		if(nullIndex > minCapacity && size < maxFill / 4 && nullIndex > HashUtil.DEFAULT_MIN_CAPACITY) rehash(nullIndex / 2);
+		return result;
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = lastIndex;
+		onNodeRemoved(pos);
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		if(KEY_EQUALS_NULL(result.ENTRY_KEY())) {
+			containsNull = false;
+			keys[nullIndex] = EMPTY_KEY_VALUE;
+			values[nullIndex] = EMPTY_VALUE;
+		}
+		else shiftKeys(pos);
+		if(nullIndex > minCapacity && size < maxFill / 4 && nullIndex > HashUtil.DEFAULT_MIN_CAPACITY) rehash(nullIndex / 2);
+		return result;
+	}
+	
 	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 		if(entrySet == null) entrySet = new MapEntrySet();
@@ -447,9 +546,9 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	}
 	
 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
-		return valuesC;
+		return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)valuesC;
 	}
 	
 	@Override
@@ -618,6 +717,10 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -634,24 +737,24 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 			POLL_FIRST_ENTRY_KEY();
 			return entry;
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 			POLL_LAST_ENTRY_KEY();
 			return entry;
@@ -659,7 +762,12 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -669,7 +777,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -778,7 +886,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -793,21 +901,21 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 				state = operator.apply(state, new ValueMapEntry(index));
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			int index = firstIndex;
 			while(index != -1) {
 				entry.set(index);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 				index = (int)links[index];
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -900,6 +1008,12 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		@Override
 		public boolean add(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 
+		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 
@@ -918,7 +1032,12 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-			return new KeyIterator();
+			return new KeyIterator(true);
+		}
+		
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return new KeyIterator(false);
 		}
 		
 		@Override
@@ -940,22 +1059,22 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 		
 		@Override
-		public KEY_TYPE FIRST_KEY() {
+		public KEY_TYPE GET_FIRST_KEY() {
 			return FIRST_ENTRY_KEY();
 		}
 		
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() {
+		public KEY_TYPE REMOVE_FIRST_KEY() {
 			return POLL_FIRST_ENTRY_KEY();
 		}
 
 		@Override
-		public KEY_TYPE LAST_KEY() {
+		public KEY_TYPE GET_LAST_KEY() {
 			return LAST_ENTRY_KEY();
 		}
 
 		@Override
-		public KEY_TYPE POLL_LAST_KEY() {
+		public KEY_TYPE REMOVE_LAST_KEY() {
 			return POLL_LAST_ENTRY_KEY();
 		}
 		
@@ -1055,7 +1174,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1070,19 +1189,19 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 				state = operator.APPLY_KEY_VALUE(state, keys[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
+			if(size() <= 0) return OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(keys[index])) return keys[index];
+				if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1099,41 +1218,50 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
 		@Deprecated
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
+		public boolean contains(Object e) { return containsValue(e); }
 		
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 		
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return LINKED_HASH_MAP.this.size();
-		}
-		
+		public int size() { return LINKED_HASH_MAP.this.size(); }
 		@Override
-		public void clear() {
-			LINKED_HASH_MAP.this.clear();
+		public void clear() { LINKED_HASH_MAP.this.clear(); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() {
+			VALUE_TYPE result = FIRST_ENTRY_VALUE();
+			POLL_FIRST_ENTRY_KEY();
+			return result; 
+		}
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() {
+			VALUE_TYPE result = LAST_ENTRY_VALUE();
+			POLL_LAST_ENTRY_KEY();
+			return result; 
 		}
-		
 		@Override
 		public void forEach(VALUE_CONSUMER VALUE_SUPER_GENERIC_TYPE action) {
 			Objects.requireNonNull(action);
@@ -1231,7 +1359,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1246,19 +1374,19 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 				state = operator.APPLY_VALUE(state, values[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(values[index])) return values[index];
+				if(filter.test(values[index])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1278,7 +1406,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
+		public FastEntryIterator(boolean start) { super(start); }
 		public FastEntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1305,7 +1433,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry;
 		
-		public EntryIterator() {}
+		public EntryIterator(boolean start) { super(start); }
 		public EntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1335,7 +1463,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
 		
-		public KeyIterator() {}
+		public KeyIterator(boolean start) { super(start); }
 		public KeyIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1357,7 +1485,7 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
-		public ValueIterator() {}
+		public ValueIterator(boolean start) { super(start); }
 		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
@@ -1377,13 +1505,16 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
 		int index = 0;
 		
-		MapIterator() {
-			next = firstIndex;
+		MapIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		MapIterator(KEY_TYPE from) {
@@ -1414,11 +1545,11 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		}
 		
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}
 
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		public int nextIndex() {
@@ -1478,20 +1609,30 @@ public class LINKED_HASH_MAP KEY_VALUE_GENERIC_TYPE extends HASH_MAP KEY_VALUE_G
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = previous;
-			previous = (int)(links[current] >> 32);
-			next = current;
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return current;
 		}
 		
 		public int nextEntry() {
 			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) moveForwards();
+			else moveBackwards();
+			if(index >= 0) index++;
+			return current;
+		}
+		
+		private void moveBackwards() {
+			current = previous;
+			previous = (int)(links[current] >> 32);
+			next = current;
+		}
+		
+		private void moveForwards() {
 			current = next;
 			next = (int)(links[current]);
 			previous = current;
-			if(index >= 0) index++;
-			return current;
 		}
 		
 		private void ensureIndexKnown() {

src/builder/resources/speiger/assets/collections/templates/maps/impl/hash/OpenHashMap.template

@@ -5,14 +5,17 @@ import java.util.ConcurrentModificationException;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif
 
 #if !TYPE_OBJECT
@@ -37,9 +40,12 @@ import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if !VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
 #if !TYPE_OBJECT
@@ -73,6 +79,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 import speiger.src.collections.objects.collections.ObjectIterator;
@@ -1049,7 +1056,7 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -1066,25 +1073,25 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 				}
 				state = operator.apply(state, new ValueMapEntry(i));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			if(containsNull) {
 				entry.set(nullIndex);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 			}
 			for(int i = nullIndex-1;i>=0;i--) {
 				if(KEY_EQUALS_NOT_NULL(keys[i])) {
 					entry.set(i);
-					if(filter.test(entry)) return entry;
+					if(filter.test(entry)) return Optional.ofNullable(entry);
 				}
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -1286,7 +1293,7 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1303,18 +1310,18 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 				}
 				state = operator.APPLY_KEY_VALUE(state, keys[i]);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
-			if(containsNull && filter.test(keys[nullIndex])) return keys[nullIndex];
+			if(size() <= 0) return OPTIONAL.empty();
+			if(containsNull && filter.test(keys[nullIndex])) return OPTIONAL.GET_OPTIONAL(keys[nullIndex]);
 			for(int i = nullIndex-1;i>=0;i--) {
-				if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(keys[i])) return keys[i];
+				if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1452,7 +1459,7 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1469,18 +1476,18 @@ public class HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GENE
 				}
 				state = operator.APPLY_VALUE(state, values[i]);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
-			if(containsNull && filter.test(values[nullIndex])) return values[nullIndex];
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
+			if(containsNull && filter.test(values[nullIndex])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[nullIndex]);
 			for(int i = nullIndex-1;i>=0;i--) {
-				if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(values[i])) return values[i];
+				if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(values[i])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[i]);
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override

src/builder/resources/speiger/assets/collections/templates/maps/impl/immutable/ImmutableOpenHashMap.template

@@ -4,14 +4,17 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif
 
 #if !TYPE_OBJECT
@@ -26,9 +29,12 @@ import speiger.src.collections.ints.functions.consumer.IntObjectConsumer;
 #if !SAME_TYPE && !TYPE_INT
 import speiger.src.collections.ints.functions.consumer.VALUE_BI_FROM_INT_CONSUMER;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if !VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 #if !TYPE_INT || !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.consumer.BI_CONSUMER;
 #endif
@@ -59,13 +65,14 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 #endif
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_SUPPLIER;
 #if !SAME_TYPE
@@ -119,7 +126,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	/** KeySet cache */
 	protected transient ORDERED_SET KEY_GENERIC_TYPE keySet;
 	/** Values cache */
-	protected transient VALUE_COLLECTION VALUE_GENERIC_TYPE valuesC;
+	protected transient VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE valuesC;
 	
 	/** Amount of Elements stored in the HashMap */
 	protected int size;
@@ -320,6 +327,10 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	@Override
 	public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
 	@Override
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
+	@Override
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
+	@Override
 	public boolean moveToFirst(KEY_TYPE key) { throw new UnsupportedOperationException(); }
 	@Override
 	public boolean moveToLast(KEY_TYPE key) { throw new UnsupportedOperationException(); }
@@ -443,6 +454,23 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		return values[lastIndex];
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[firstIndex], values[firstIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[lastIndex], values[lastIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() { throw new UnsupportedOperationException(); }
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() { throw new UnsupportedOperationException(); }
+
 	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 		if(entrySet == null) entrySet = new MapEntrySet();
@@ -456,7 +484,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	}
 	
 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
 		return valuesC;
 	}
@@ -609,6 +637,10 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -621,24 +653,29 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		public boolean moveToLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() { throw new UnsupportedOperationException(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() { throw new UnsupportedOperationException(); }
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() { throw new UnsupportedOperationException(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() { throw new UnsupportedOperationException(); }
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -648,7 +685,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -757,7 +794,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -772,21 +809,21 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 				state = operator.apply(state, new BasicEntryKV_BRACES(keys[index], values[index]));
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES();
 			int index = firstIndex;
 			while(index != -1) {
 				entry.set(keys[index], values[index]);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 				index = (int)links[index];
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -861,6 +898,12 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 			throw new UnsupportedOperationException();
 		}
 		
+		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 
@@ -875,7 +918,12 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-			return new KeyIterator();
+			return new KeyIterator(true);
+		}
+		
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return new KeyIterator(false);
 		}
 		
 		@Override
@@ -895,20 +943,20 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		public void clear() { throw new UnsupportedOperationException(); }
 		
 		@Override
-		public KEY_TYPE FIRST_KEY() {
+		public KEY_TYPE GET_FIRST_KEY() {
 			return FIRST_ENTRY_KEY();
 		}
 		
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() { throw new UnsupportedOperationException(); }
+		public KEY_TYPE REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }
 
 		@Override
-		public KEY_TYPE LAST_KEY() {
+		public KEY_TYPE GET_LAST_KEY() {
 			return LAST_ENTRY_KEY();
 		}
 
 		@Override
-		public KEY_TYPE POLL_LAST_KEY() { throw new UnsupportedOperationException(); }
+		public KEY_TYPE REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
 		
 		@Override
 		public void forEach(CONSUMER KEY_SUPER_GENERIC_TYPE action) {
@@ -1006,7 +1054,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1021,19 +1069,19 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 				state = operator.APPLY_KEY_VALUE(state, keys[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_KEY_VALUE;
+			if(size() <= 0) return OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(keys[index])) return keys[index];
+				if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1050,39 +1098,42 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		}
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
 		@Deprecated
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
+		public boolean contains(Object e) { return containsValue(e); }
 		
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 		
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return IMMUTABLE_HASH_MAP.this.size();
-		}
-		
+		public int size() { return IMMUTABLE_HASH_MAP.this.size(); }
 		@Override
 		public void clear() { throw new UnsupportedOperationException(); }
-		
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
 		@Override
 		public void forEach(VALUE_CONSUMER VALUE_SUPER_GENERIC_TYPE action) {
 			int index = firstIndex;
@@ -1179,7 +1230,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1194,19 +1245,19 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 				state = operator.APPLY_VALUE(state, values[index]);
 				index = (int)links[index];
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return EMPTY_VALUE;
+			if(size() <= 0) return VALUE_OPTIONAL.empty();
 			int index = firstIndex;
 			while(index != -1){
-				if(filter.test(values[index])) return values[index];
+				if(filter.test(values[index])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[index]);
 				index = (int)links[index];
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1226,7 +1277,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
+		public FastEntryIterator(boolean start) { super(start); }
 		public FastEntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1252,7 +1303,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		
-		public EntryIterator() {}
+		public EntryIterator(boolean start) { super(start); }
 		public EntryIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1279,7 +1330,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
 		
-		public KeyIterator() {}
+		public KeyIterator(boolean start) { super(start); }
 		public KeyIterator(KEY_TYPE from) {
 			super(from);
 		}
@@ -1301,7 +1352,7 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
-		public ValueIterator() {}
+		public ValueIterator(boolean start) { super(start); }
 		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
@@ -1322,13 +1373,16 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
 		int index = 0;
 		
-		MapIterator() {
-			next = firstIndex;
+		MapIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		MapIterator(KEY_TYPE from) {
@@ -1359,11 +1413,11 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		}
 		
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}
 
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		public int nextIndex() {
@@ -1380,20 +1434,30 @@ public class IMMUTABLE_HASH_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = previous;
-			previous = (int)(links[current] >> 32);
-			next = current;
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return current;
 		}
 		
 		public int nextEntry() {
 			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) moveForwards();
+			else moveBackwards();
+			if(index >= 0) index++;
+			return current;
+		}
+		
+		private void moveBackwards() {
+			current = previous;
+			previous = (int)(links[current] >> 32);
+			next = current;
+		}
+		
+		private void moveForwards() {
 			current = next;
 			next = (int)(links[current]);
 			previous = current;
-			if(index >= 0) index++;
-			return current;
 		}
 		
 		private void ensureIndexKnown() {

src/builder/resources/speiger/assets/collections/templates/maps/impl/misc/ArrayMap.template

@@ -4,14 +4,17 @@ import java.util.Arrays;
 import java.util.Map;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif
 
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
@@ -26,9 +29,12 @@ import speiger.src.collections.ints.functions.consumer.IntObjectConsumer;
 #if !SAME_TYPE && !TYPE_INT
 import speiger.src.collections.ints.functions.consumer.VALUE_BI_FROM_INT_CONSUMER;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if!VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 #if !TYPE_INT || !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.consumer.BI_CONSUMER;
 #endif
@@ -46,7 +52,7 @@ import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_SUPPLIER;
 #if !SAME_TYPE
@@ -66,6 +72,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !VALUE_OBJECT
@@ -105,7 +112,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	/** KeySet cache */
 	protected ORDERED_SET KEY_GENERIC_TYPE keySet;
 	/** Values cache */
-	protected VALUE_COLLECTION VALUE_GENERIC_TYPE valuesC;
+	protected VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE valuesC;
 	/** EntrySet cache */
 	protected FastOrderedSet KEY_VALUE_GENERIC_TYPE entrySet;
 	
@@ -275,6 +282,27 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		return lastValue;
 	}
 	
+	@Override
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) {
+		int index = findIndex(key);
+		if(index < 0) {
+			insertIndex(0, key, value);
+			size++;
+			return getDefaultReturnValue();
+		}
+		return values[index];
+	}
+	
+	@Override
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) {
+		int index = findIndex(key);
+		if(index < 0) {
+			insertIndex(size++, key, value);
+			return getDefaultReturnValue();
+		}
+		return values[index];
+	}
+	
 	@Override
 	public boolean moveToFirst(KEY_TYPE key) {
 		int index = findIndex(key);
@@ -402,6 +430,34 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		return result;
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[0], values[0]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[size-1], values[size-1]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[0], values[0]);
+		removeIndex(0);
+		return result;
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[size-1], values[size-1]);
+		removeIndex(size-1);
+		return result;
+	}
+	
 	@Override
 	public VALUE_TYPE REMOVE_VALUE(KEY_TYPE key) {
 		int index = findIndex(key);
@@ -461,7 +517,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}
 
 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
 		return valuesC;
 	}
@@ -812,6 +868,10 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -828,24 +888,24 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 			POLL_FIRST_ENTRY_KEY();
 			return entry;
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 			POLL_LAST_ENTRY_KEY();
 			return entry;
@@ -853,7 +913,12 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -863,7 +928,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -955,7 +1020,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -967,19 +1032,19 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 				}
 				state = operator.apply(state, new ValueMapEntry(i));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			MapEntry entry = new MapEntry();
 			for(int i = 0;i<size;i++) {
 				entry.set(i);
-				if(filter.test(entry)) return entry;
+				if(filter.test(entry)) return Optional.ofNullable(entry);
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override
@@ -1065,6 +1130,10 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		@Override
 		public boolean add(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
@@ -1073,7 +1142,9 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		@Override
 		public boolean moveToLast(KEY_TYPE o) { return ARRAY_MAP.this.moveToLast(o); }
 		@Override
-		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() { return new KeyIterator(); }
+		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() { return new KeyIterator(true); }
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() { return new KeyIterator(false); }
 		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) { return new KeyIterator(fromElement); } 
 		@Override
@@ -1081,13 +1152,13 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		@Override
 		public void clear() { ARRAY_MAP.this.clear(); }
 		@Override
-		public KEY_TYPE FIRST_KEY() { return FIRST_ENTRY_KEY(); }
+		public KEY_TYPE GET_FIRST_KEY() { return FIRST_ENTRY_KEY(); }
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() { return POLL_FIRST_ENTRY_KEY(); }
+		public KEY_TYPE REMOVE_FIRST_KEY() { return POLL_FIRST_ENTRY_KEY(); }
 		@Override
-		public KEY_TYPE LAST_KEY() { return LAST_ENTRY_KEY(); }
+		public KEY_TYPE GET_LAST_KEY() { return LAST_ENTRY_KEY(); }
 		@Override
-		public KEY_TYPE POLL_LAST_KEY() { return POLL_LAST_ENTRY_KEY(); }
+		public KEY_TYPE REMOVE_LAST_KEY() { return POLL_LAST_ENTRY_KEY(); }
 		
 		@Override
 		public KeySet copy() { throw new UnsupportedOperationException(); }
@@ -1162,7 +1233,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1174,16 +1245,16 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 				}
 				state = operator.APPLY_KEY_VALUE(state, keys[i]);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(int i = 0;i<size;i++) {
-				if(filter.test(keys[i])) return keys[i];
+				if(filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 			}
-			return EMPTY_KEY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1197,40 +1268,49 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		}
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
+		public boolean contains(Object e) { return containsValue(e); }
 		
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 		
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return ARRAY_MAP.this.size();
-		}
-		
+		public int size() { return ARRAY_MAP.this.size(); }
 		@Override
-		public void clear() {
-			ARRAY_MAP.this.clear();
+		public void clear() { ARRAY_MAP.this.clear(); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() {
+			VALUE_TYPE result = FIRST_ENTRY_VALUE();
+			POLL_FIRST_ENTRY_KEY();
+			return result; 
+		}
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() {
+			VALUE_TYPE result = LAST_ENTRY_VALUE();
+			POLL_LAST_ENTRY_KEY();
+			return result; 
 		}
-		
 		@Override
 		public void forEach(VALUE_CONSUMER VALUE_SUPER_GENERIC_TYPE action) {
 			Objects.requireNonNull(action);
@@ -1294,7 +1374,7 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 #endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1306,16 +1386,16 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 				}
 				state = operator.APPLY_VALUE(state, values[i]);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(int i = 0;i<size;i++) {
-				if(filter.test(values[i])) return values[i];
+				if(filter.test(values[i])) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(values[i]);
 			}
-			return EMPTY_VALUE;
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -1332,10 +1412,8 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
-		public FastEntryIterator(KEY_TYPE from) {
-			index = findIndex(from);
-		}
+		public FastEntryIterator(boolean start) { super(start); }
+		public FastEntryIterator(KEY_TYPE element) { super(element); }
 		
 		@Override
 		public MAP.Entry KEY_VALUE_GENERIC_TYPE next() {
@@ -1358,11 +1436,8 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = null;
 		
-		public EntryIterator() {}
-		public EntryIterator(KEY_TYPE from) {
-			index = findIndex(from);
-			if(index == -1) throw new NoSuchElementException();
-		}
+		public EntryIterator(boolean start) { super(start); }
+		public EntryIterator(KEY_TYPE element) { super(element); }
 		
 		@Override
 		public MAP.Entry KEY_VALUE_GENERIC_TYPE next() {
@@ -1389,11 +1464,8 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
-		public KeyIterator() {}
-		public KeyIterator(KEY_TYPE element) {
-			index = findIndex(element);
-			if(index == -1) throw new NoSuchElementException();
-		}
+		public KeyIterator(boolean start) { super(start); }
+		public KeyIterator(KEY_TYPE element) { super(element); }
 		
 		@Override
 		public KEY_TYPE PREVIOUS() {
@@ -1413,6 +1485,9 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
+		public ValueIterator(boolean start) { super(start); }
+		public ValueIterator(KEY_TYPE element) { super(element); }
+		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
 			return values[previousEntry()];
@@ -1431,23 +1506,37 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int index;
 		int lastReturned = -1;
 		
+		MapIterator(boolean start) {
+			this.forward = start;
+			this.index = start ? 0 : size;
+		}
+		
+		MapIterator(KEY_TYPE element) {
+			this.forward = true;
+			index = findIndex(element);
+			if(index == -1) throw new NoSuchElementException();
+		}
+		
 		public boolean hasNext() {
-			return index < size;
+			return forward ? index < size : index > 0;
 		}
 		
 		public boolean hasPrevious() {
-			return index > 0;
+			return forward ? index > 0 : index < size;
 		}
 		
 		public int nextIndex() {
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		public int previousIndex() {
-			return index-1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		public void remove() {
@@ -1460,26 +1549,42 @@ public class ARRAY_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_GEN
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
+			if(forward) {
 				index--;
 				return (lastReturned = index);
 			}
-		
-		public int nextEntry() {
-			if(!hasNext()) throw new NoSuchElementException();
 			lastReturned = index;
 			return index++;
 		}
 		
+		public int nextEntry() {
+			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) {
+				lastReturned = index;
+				return index++;
+			}
+			index--;
+			return (lastReturned = index);
+		}
+		
 		public int skip(int amount) {
 			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+			return forward ? moveForward(amount) : moveBackwards(amount);
+		}
+		
+		public int back(int amount) {
+			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+			return forward ? moveBackwards(amount) : moveForward(amount);
+		}
+		
+		private int moveForward(int amount) {
 			int steps = Math.min(amount, size() - index);
 			index += steps;
 			if(steps > 0) lastReturned = Math.min(index-1, size()-1);
 			return steps;
 		}
 		
-		public int back(int amount) {
-			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+		private int moveBackwards(int amount) {
 			int steps = Math.min(amount, index);
 			index -= steps;
 			if(steps > 0) lastReturned = Math.min(index, size()-1);

src/builder/resources/speiger/assets/collections/templates/maps/impl/misc/LinkedEnumMap.template

@@ -18,7 +18,7 @@ import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
 import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET;
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ABSTRACT_COLLECTION;
-import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ITERATOR;
 #if !VALUE_OBJECT && !SAME_TYPE
 import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_CONSUMER;
@@ -216,6 +216,28 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		return getDefaultReturnValue();
 	}
 	
+	@Override
+	public VALUE_TYPE putFirst(T key, VALUE_TYPE value) {
+		int index = key.ordinal();
+		if(isSet(index)) return values[index];
+		set(index);
+		values[index] = value;
+		onNodeAdded(index);
+		moveToFirstIndex(index);
+		return getDefaultReturnValue();
+	}
+	
+	@Override
+	public VALUE_TYPE putLast(T key, VALUE_TYPE value) {
+		int index = key.ordinal();
+		if(isSet(index)) return values[index];
+		set(index);
+		values[index] = value;
+		onNodeAdded(index);
+		moveToLastIndex(index);
+		return getDefaultReturnValue();
+	}
+	
 	@Override
 	public boolean moveToFirst(T key) {
 		int index = key.ordinal();
@@ -312,6 +334,42 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		return values[lastIndex];
 	}
 	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[firstIndex], values[firstIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		return new BasicEntryKV_BRACES(keys[lastIndex], values[lastIndex]);
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = firstIndex;
+		firstIndex = (int)links[pos];
+		if(0 <= firstIndex) links[firstIndex] |= 0xFFFFFFFF00000000L;
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		values[result.ENTRY_KEY().ordinal()] = EMPTY_VALUE;
+		return result;
+	}
+	
+	@Override
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() {
+		if(size == 0) throw new NoSuchElementException();
+		int pos = lastIndex;
+		firstIndex = (int)links[pos];
+		if(0 <= firstIndex) links[firstIndex] |= 0xFFFFFFFF00000000L;
+		BasicEntry KEY_VALUE_GENERIC_TYPE result = new BasicEntryKV_BRACES(keys[pos], values[pos]);
+		size--;
+		values[result.ENTRY_KEY().ordinal()] = EMPTY_VALUE;
+		return result;
+	}
+	
 	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 		if(entrySet == null) entrySet = new MapEntrySet();
@@ -325,9 +383,9 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	}
 	
 	@Override
-	public VALUE_COLLECTION VALUE_GENERIC_TYPE values() {
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
 		if(valuesC == null) valuesC = new Values();
-		return valuesC;
+		return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)valuesC;
 	}
 	
 	@Override
@@ -415,6 +473,10 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	}
 	
 	private class MapEntrySet extends AbstractObjectSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> implements ORDERED_MAP.FastOrderedSet KEY_VALUE_GENERIC_TYPE {
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -431,24 +493,24 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() {
 			return new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() {
 			return new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(FIRST_ENTRY_KEY(), FIRST_ENTRY_VALUE());
 			POLL_FIRST_ENTRY_KEY();
 			return entry;
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() {
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() {
 			BasicEntry KEY_VALUE_GENERIC_TYPE entry = new BasicEntryKV_BRACES(LAST_ENTRY_KEY(), LAST_ENTRY_VALUE());
 			POLL_LAST_ENTRY_KEY();
 			return entry;
@@ -456,7 +518,12 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() {
-			return new EntryIterator();
+			return new EntryIterator(true);
+		}
+		
+		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() {
+			return new EntryIterator(false);
 		}
 		
 		@Override
@@ -466,7 +533,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> fastIterator() {
-			return new FastEntryIterator();
+			return new FastEntryIterator(true);
 		}
 		
 		@Override
@@ -574,7 +641,10 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		public boolean add(T o) {
 			throw new UnsupportedOperationException();
 		}
-		
+		@Override
+		public void addFirst(T o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(T o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(T o) { throw new UnsupportedOperationException(); }
 
@@ -593,7 +663,12 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		
 		@Override
 		public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-			return new KeyIterator();
+			return new KeyIterator(true);
+		}
+		
+		@Override
+		public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return new KeyIterator(false);
 		}
 		
 		@Override
@@ -614,22 +689,22 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		}
 		
 		@Override
-		public T FIRST_KEY() {
+		public T GET_FIRST_KEY() {
 			return FIRST_ENTRY_KEY();
 		}
 		
 		@Override
-		public T POLL_FIRST_KEY() {
+		public T REMOVE_FIRST_KEY() {
 			return POLL_FIRST_ENTRY_KEY();
 		}
 
 		@Override
-		public T LAST_KEY() {
+		public T GET_LAST_KEY() {
 			return LAST_ENTRY_KEY();
 		}
 
 		@Override
-		public T POLL_LAST_KEY() {
+		public T REMOVE_LAST_KEY() {
 			return POLL_LAST_ENTRY_KEY();
 		}
 		
@@ -656,41 +731,50 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 #endif
 	}
 	
-	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE {
+	private class Values extends VALUE_ABSTRACT_COLLECTION VALUE_GENERIC_TYPE implements VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE {
 #if VALUE_OBJECT
 		@Override
 		@Deprecated
-		public boolean contains(Object e) {
-			return containsValue(e);
-		}
+		public boolean contains(Object e) { return containsValue(e); }
 		
 #else
 		@Override
-		public boolean contains(VALUE_TYPE e) {
-			return containsValue(e);
-		}
+		public boolean contains(VALUE_TYPE e) { return containsValue(e); }
 		
 #endif
 		@Override
-		public boolean add(VALUE_TYPE o) {
-			throw new UnsupportedOperationException();
-		}
-
+		public boolean add(VALUE_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
-		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() {
-			return new ValueIterator();
-		}
-		
+		public VALUE_ITERATOR VALUE_GENERIC_TYPE iterator() { return new ValueIterator(true); }
 		@Override
-		public int size() {
-			return LINKED_ENUM_MAP.this.size();
-		}
-		
+		public int size() { return LINKED_ENUM_MAP.this.size(); }
 		@Override
-		public void clear() {
-			LINKED_ENUM_MAP.this.clear();
+		public void clear() { LINKED_ENUM_MAP.this.clear(); }
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE reversed() { return new VALUE_ABSTRACT_COLLECTION.VALUE_REVERSED_ORDERED_COLLECTIONVALUE_BRACES(this, this::reverseIterator); }
+		private VALUE_ITERATOR VALUE_GENERIC_TYPE reverseIterator() {
+			return new ValueIterator(false);
+		}
+		@Override
+		public void addFirst(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(VALUE_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE VALUE_GET_FIRST_KEY() { return FIRST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_FIRST_KEY() {
+			VALUE_TYPE result = FIRST_ENTRY_VALUE();
+			POLL_FIRST_ENTRY_KEY();
+			return result; 
+		}
+		@Override
+		public VALUE_TYPE VALUE_GET_LAST_KEY() { return LAST_ENTRY_VALUE(); }
+		@Override
+		public VALUE_TYPE VALUE_REMOVE_LAST_KEY() {
+			VALUE_TYPE result = LAST_ENTRY_VALUE();
+			POLL_LAST_ENTRY_KEY();
+			return result; 
 		}
-		
 #if VALUE_OBJECT
 		@Override
 		public void forEach(Consumer VALUE_SUPER_GENERIC_TYPE action) {
@@ -715,7 +799,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	private class FastEntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry = new MapEntry();
 		
-		public FastEntryIterator() {}
+		public FastEntryIterator(boolean start) { super(start); }
 		public FastEntryIterator(T from) {
 			super(from);
 		}
@@ -742,7 +826,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	private class EntryIterator extends MapIterator implements ObjectListIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> {
 		MapEntry entry;
 		
-		public EntryIterator() {}
+		public EntryIterator(boolean start) { super(start); }
 		public EntryIterator(T from) {
 			super(from);
 		}
@@ -772,7 +856,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	
 	private class KeyIterator extends MapIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
 		
-		public KeyIterator() {}
+		public KeyIterator(boolean start) { super(start); }
 		public KeyIterator(T from) {
 			super(from);
 		}
@@ -794,7 +878,7 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	}
 	
 	private class ValueIterator extends MapIterator implements VALUE_LIST_ITERATOR VALUE_GENERIC_TYPE {
-		public ValueIterator() {}
+		public ValueIterator(boolean start) { super(start); }
 		
 		@Override
 		public VALUE_TYPE VALUE_PREVIOUS() {
@@ -815,16 +899,20 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 	}
 	
 	private class MapIterator {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
 		int index = 0;
 		
-		MapIterator() {
-			next = firstIndex;
+		MapIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		MapIterator(T from) {
+			this.forward = true;
 			previous = from.ordinal() - 1;
 			index = from.ordinal();
 			next = from.ordinal();
@@ -832,11 +920,11 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		}
 		
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}
 
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		public int nextIndex() {
@@ -871,20 +959,30 @@ public class LINKED_ENUM_MAP KEY_ENUM_VALUE_GENERIC_TYPE extends ENUM_MAP KEY_VA
 		
 		public int previousEntry() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = previous;
-			previous = (int)(links[current] >> 32);
-			next = current;
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return current;
 		}
 		
 		public int nextEntry() {
 			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) moveForwards();
+			else moveBackwards();
+			if(index >= 0) index++;
+			return current;
+		}
+		
+		private void moveBackwards() {
+			current = previous;
+			previous = (int)(links[current] >> 32);
+			next = current;
+		}
+		
+		private void moveForwards() {
 			current = next;
 			next = (int)(links[current]);
 			previous = current;
-			if(index >= 0) index++;
-			return current;
 		}
 		
 		private void ensureIndexKnown() {

src/builder/resources/speiger/assets/collections/templates/maps/impl/tree/AVLTreeMap.template

@@ -6,15 +6,18 @@ import java.util.Map;
 import java.util.Comparator;
 #endif
 import java.util.Objects;
+import java.util.Optional;
 import java.util.NoSuchElementException;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif
 
 
@@ -37,9 +40,12 @@ import speiger.src.collections.PACKAGE.functions.function.FUNCTION;
 #if !TYPE_INT || !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.consumer.BI_CONSUMER;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if!VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
@@ -73,6 +79,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT && !VALUE_OBJECT
@@ -1323,7 +1330,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1335,15 +1342,15 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 				}
 				state = operator.APPLY_KEY_VALUE(state, entry.key);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Node KEY_VALUE_GENERIC_TYPE entry = start(), end = end();entry != null && (end == null || (end != previous(entry)));entry = next(entry))
-				if(filter.test(entry.key)) return entry.key;
-			return EMPTY_KEY_VALUE;
+				if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -2026,7 +2033,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 			}
 			
 			@Override
-			public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+			public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 				Objects.requireNonNull(operator);
 				MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 				boolean empty = true;
@@ -2038,19 +2045,19 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 					}
 					state = operator.apply(state, new BasicEntryKV_BRACES(entry.key, entry.value));
 				}
-				return state;
+				return empty ? Optional.empty() : Optional.ofNullable(state);
 			}
 			
 			@Override
-			public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+			public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 				Objects.requireNonNull(filter);
-				if(size() <= 0) return null;
+				if(size() <= 0) return Optional.empty();
 				BasicEntry KEY_VALUE_GENERIC_TYPE subEntry = new BasicEntryKV_BRACES();
 				for(Node KEY_VALUE_GENERIC_TYPE entry = subLowest(), last = subHighest();entry != null && (last == null || last != previous(entry));entry = next(entry)) {
 					subEntry.set(entry.key, entry.value);
-					if(filter.test(subEntry)) return subEntry;
+					if(filter.test(subEntry)) return Optional.ofNullable(subEntry);
 				}
-				return null;
+				return Optional.empty();
 			}
 			
 			@Override
@@ -2165,7 +2172,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 			
 #endif
 			@Override
-			public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+			public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 				Objects.requireNonNull(operator);
 				VALUE_TYPE state = EMPTY_VALUE;
 				boolean empty = true;
@@ -2177,15 +2184,15 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 					}
 					state = operator.APPLY_VALUE(state, entry.value);
 				}
-				return state;
+				return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 			}
 			
 			@Override
-			public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+			public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 				Objects.requireNonNull(filter);
 				for(Node KEY_VALUE_GENERIC_TYPE entry = subLowest(), last = subHighest();entry != null && (last == null || last != previous(entry));entry = next(entry))
-					if(filter.test(entry.value)) return entry.value;
-				return EMPTY_VALUE;
+					if(filter.test(entry.value)) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(entry.value);
+				return VALUE_OPTIONAL.empty();
 			}
 			
 			@Override
@@ -2521,7 +2528,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 		
 		#endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -2533,15 +2540,15 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 				}
 				state = operator.APPLY_VALUE(state, entry.value);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Node KEY_VALUE_GENERIC_TYPE entry = first;entry != null;entry = entry.next())
-				if(filter.test(entry.value)) return entry.value;
-			return EMPTY_VALUE;
+				if(filter.test(entry.value)) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(entry.value);
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -2687,7 +2694,7 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -2699,19 +2706,19 @@ public class AVL_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_
 				}
 				state = operator.apply(state, new BasicEntryKV_BRACES(entry.key, entry.value));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			BasicEntry KEY_VALUE_GENERIC_TYPE subEntry = new BasicEntryKV_BRACES();
 			for(Node KEY_VALUE_GENERIC_TYPE entry = first;entry != null;entry = entry.next()) {
 				subEntry.set(entry.key, entry.value);
-				if(filter.test(subEntry)) return subEntry;
+				if(filter.test(subEntry)) return Optional.ofNullable(subEntry);
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override

src/builder/resources/speiger/assets/collections/templates/maps/impl/tree/RBTreeMap.template

@@ -6,15 +6,18 @@ import java.util.Map;
 import java.util.Comparator;
 #endif
 import java.util.Objects;
+import java.util.Optional;
 import java.util.NoSuchElementException;
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
 import java.util.function.Predicate;
 #if !TYPE_OBJECT && JDK_TYPE
 import java.util.function.PREDICATE;
+import java.util.OPTIONAL;
 #endif
 #if !SAME_TYPE && JDK_VALUE && !VALUE_OBJECT
 import java.util.function.VALUE_PREDICATE;
+import java.util.VALUE_OPTIONAL;
 #endif
 
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
@@ -36,9 +39,12 @@ import speiger.src.collections.PACKAGE.functions.function.FUNCTION;
 #if !TYPE_INT || !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.consumer.BI_CONSUMER;
 #endif
-#if !TYPE_OBJECT && !VALUE_BOOLEAN && !JDK_TYPE
+#if !TYPE_OBJECT && !JDK_TYPE
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#if!VALUE_BOOLEAN
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+#endif
 import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 #if !SAME_TYPE
 import speiger.src.collections.PACKAGE.functions.function.SINGLE_UNARY_OPERATOR;
@@ -72,6 +78,7 @@ import speiger.src.collections.objects.functions.consumer.VALUE_BI_FROM_OBJECT_C
 #endif
 #if !JDK_VALUE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_PREDICATE;
+import speiger.src.collections.VALUE_PACKAGE.functions.VALUE_OPTIONAL;
 #endif
 #endif
 #if !TYPE_OBJECT && !VALUE_OBJECT
@@ -1379,7 +1386,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(SINGLE_UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_KEY_VALUE;
 			boolean empty = true;
@@ -1391,15 +1398,15 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 				}
 				state = operator.APPLY_KEY_VALUE(state, entry.key);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Node KEY_VALUE_GENERIC_TYPE entry = start(), end = end();entry != null && (end == null || (end != previous(entry)));entry = next(entry))
-				if(filter.test(entry.key)) return entry.key;
-			return EMPTY_KEY_VALUE;
+				if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
+			return OPTIONAL.empty();
 		}
 		
 		@Override
@@ -2092,7 +2099,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 			}
 			
 			@Override
-			public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+			public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 				Objects.requireNonNull(operator);
 				MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 				boolean empty = true;
@@ -2104,19 +2111,19 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 					}
 					state = operator.apply(state, new BasicEntryKV_BRACES(entry.key, entry.value));
 				}
-				return state;
+				return empty ? Optional.empty() : Optional.ofNullable(state);
 			}
 			
 			@Override
-			public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+			public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 				Objects.requireNonNull(filter);
-				if(size() <= 0) return null;
+				if(size() <= 0) return Optional.empty();
 				BasicEntry KEY_VALUE_GENERIC_TYPE subEntry = new BasicEntryKV_BRACES();
 				for(Node KEY_VALUE_GENERIC_TYPE entry = subLowest(), last = subHighest();entry != null && (last == null || last != previous(entry));entry = next(entry)) {
 					subEntry.set(entry.key, entry.value);
-					if(filter.test(subEntry)) return subEntry;
+					if(filter.test(subEntry)) return Optional.ofNullable(subEntry);
 				}
-				return null;
+				return Optional.empty();
 			}
 			
 			@Override
@@ -2231,7 +2238,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 			
 #endif
 			@Override
-			public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+			public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 				Objects.requireNonNull(operator);
 				VALUE_TYPE state = EMPTY_VALUE;
 				boolean empty = true;
@@ -2243,15 +2250,15 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 					}
 					state = operator.APPLY_VALUE(state, entry.value);
 				}
-				return state;
+				return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 			}
 			
 			@Override
-			public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+			public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 				Objects.requireNonNull(filter);
 				for(Node KEY_VALUE_GENERIC_TYPE entry = subLowest(), last = subHighest();entry != null && (last == null || last != previous(entry));entry = next(entry))
-					if(filter.test(entry.value)) return entry.value;
-				return EMPTY_VALUE;
+					if(filter.test(entry.value)) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(entry.value);
+				return VALUE_OPTIONAL.empty();
 			}
 			
 			@Override
@@ -2587,7 +2594,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 		
 		#endif
 		@Override
-		public VALUE_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE reduce(VALUE_SINGLE_UNARY_OPERATOR VALUE_VALUE_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			VALUE_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -2599,15 +2606,15 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 				}
 				state = operator.APPLY_VALUE(state, entry.value);
 			}
-			return state;
+			return empty ? VALUE_OPTIONAL.empty() : VALUE_OPTIONAL.GET_OPTIONAL_VALUE(state);
 		}
 		
 		@Override
-		public VALUE_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
+		public VALUE_OPTIONAL VALUE_GENERIC_TYPE findFirst(VALUE_PREDICATE VALUE_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Node KEY_VALUE_GENERIC_TYPE entry = first;entry != null;entry = entry.next())
-				if(filter.test(entry.value)) return entry.value;
-			return EMPTY_VALUE;
+				if(filter.test(entry.value)) return VALUE_OPTIONAL.GET_OPTIONAL_VALUE(entry.value);
+			return VALUE_OPTIONAL.empty();
 		}
 		
 		@Override
@@ -2753,7 +2760,7 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> reduce(ObjectObjectUnaryOperator<MAP.Entry KEY_VALUE_GENERIC_TYPE, MAP.Entry KEY_VALUE_GENERIC_TYPE> operator) {
 			Objects.requireNonNull(operator);
 			MAP.Entry KEY_VALUE_GENERIC_TYPE state = null;
 			boolean empty = true;
@@ -2765,19 +2772,19 @@ public class RB_TREE_MAP KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP KEY_VALUE_G
 				}
 				state = operator.apply(state, new BasicEntryKV_BRACES(entry.key, entry.value));
 			}
-			return state;
+			return empty ? Optional.empty() : Optional.ofNullable(state);
 		}
 		
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
+		public Optional<MAP.Entry KEY_VALUE_GENERIC_TYPE> findFirst(Predicate<MAP.Entry KEY_VALUE_GENERIC_TYPE> filter) {
 			Objects.requireNonNull(filter);
-			if(size() <= 0) return null;
+			if(size() <= 0) return Optional.empty();
 			BasicEntry KEY_VALUE_GENERIC_TYPE subEntry = new BasicEntryKV_BRACES();
 			for(Node KEY_VALUE_GENERIC_TYPE entry = first;entry != null;entry = entry.next()) {
 				subEntry.set(entry.key, entry.value);
-				if(filter.test(subEntry)) return subEntry;
+				if(filter.test(subEntry)) return Optional.ofNullable(subEntry);
 			}
-			return null;
+			return Optional.empty();
 		}
 		
 		@Override

src/builder/resources/speiger/assets/collections/templates/maps/interfaces/Map.template

@@ -154,7 +154,7 @@ public interface MAP KEY_VALUE_GENERIC_TYPE extends Map<CLASS_TYPE, CLASS_VALUE_
 	 * @return the last present value or default return	value.
 	 */
 	public default CLASS_VALUE_TYPE put(Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE> entry) {
-		return put(entry.getKey(), entry.getValue());
+		return put(OBJ_TO_KEY(entry.getKey()), OBJ_TO_VALUE(entry.getValue()));
 	}
 
 #endif

src/builder/resources/speiger/assets/collections/templates/maps/interfaces/OrderedMap.template

@@ -1,8 +1,15 @@
 package speiger.src.collections.PACKAGE.maps.interfaces;
 
+#if JAVA_VERSION>=21
+import java.util.Map;
+import java.util.SequencedMap;
+
+#endif
 #if MAPS_FEATURE
 import speiger.src.collections.PACKAGE.utils.maps.MAPS;
 #endif
+import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
 #endif
@@ -17,7 +24,11 @@ import speiger.src.collections.objects.sets.ObjectOrderedSet;
  * @Type(T)
  * @ValueType(V)
  */
+#if JAVA_VERSION>=21
+public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERIC_TYPE, SequencedMap<CLASS_TYPE, CLASS_VALUE_TYPE>
+#else
 public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERIC_TYPE
+#endif
 {
 	/**
 	 * A customized put method that allows you to insert into the first index.
@@ -37,6 +48,26 @@ public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERI
 	 */
 	public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value);
 	
+	/**
+	 * A alternative to putAndMoveToFirst.
+	 * This method simply puts an entry at the first spot of the Map but only if the entry is missing.
+	 * @param key the key that should be inserted
+	 * @param value the value that should be inserted
+	 * @return the previous present or default return value
+	 * @see java.util.Map#put(Object, Object)
+	 */
+	public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value);
+	
+	/**
+	 * A alternative to putAndMoveToLast.
+	 * This method simply puts an entry at the last spot of the Map but only if the entry is missing.
+	 * @param key the key that should be inserted
+	 * @param value the value that should be inserted
+	 * @return the previous present or default return value
+	 * @see java.util.Map#put(Object, Object)
+	 */
+	public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value);
+	
 	/**
 	 * A specific move method to move a given key/value to the first index.
 	 * @param key that should be moved to the first index
@@ -97,13 +128,34 @@ public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERI
 	 */
 	public VALUE_TYPE LAST_ENTRY_VALUE();
 	
+	@Java21
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry();
+	@Java21
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry();
+	@Java21
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry();
+	@Java21
+	public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry();
 	@Override
 	public ORDERED_MAP KEY_VALUE_GENERIC_TYPE copy();
 	@Override
 	public ORDERED_SET KEY_GENERIC_TYPE keySet();
 	@Override
+	public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values();
+	@Override
 	public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET();
+	@Java21
+	public default ORDERED_MAP KEY_VALUE_GENERIC_TYPE reversed() { return new ABSTRACT_MAP.REVERSED_ORDERED_MAPKV_BRACES(this); }
 	
+#if JAVA_VERSION>=21
+	@Override
+	default ORDERED_SET KEY_GENERIC_TYPE sequencedKeySet() { return keySet(); }
+	@Override
+	default VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE sequencedValues() { return values(); }
+	@Override
+	default ObjectOrderedSet<Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE>> sequencedEntrySet() { return (ObjectOrderedSet<Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE>>)(Object)ENTRY_SET(); }
+	
+#endif
 #if MAPS_FEATURE
 	/**
 	 * Creates a Wrapped SortedMap that is Synchronized
@@ -130,6 +182,22 @@ public interface ORDERED_MAP KEY_VALUE_GENERIC_TYPE extends MAP KEY_VALUE_GENERI
 	@Override
 	public default ORDERED_MAP KEY_VALUE_GENERIC_TYPE unmodifiable() { return MAPS.unmodifiable(this); }
 	
+#endif
+#if JAVA_VERSION>=21
+#if !SAME_TYPE || !TYPE_OBJECT
+	@Override
+	@Deprecated
+	public default CLASS_VALUE_TYPE putFirst(CLASS_TYPE k, CLASS_VALUE_TYPE v) {
+		return putFirst(OBJ_TO_KEY(k), OBJ_TO_VALUE(v));
+	}
+	
+	@Override
+	@Deprecated
+	public default CLASS_VALUE_TYPE putLast(CLASS_TYPE k, CLASS_VALUE_TYPE v) {
+		return putLast(OBJ_TO_KEY(k), OBJ_TO_VALUE(v));
+	}
+	
+#endif
 #endif
 	/**
 	 * Fast Ordered Entry Set that allows for a faster Entry Iterator by recycling the Entry Object and just exchanging 1 internal value

src/builder/resources/speiger/assets/collections/templates/queues/ArrayFIFOQueue.template

@@ -7,12 +7,18 @@ import java.util.function.Consumer;
 import java.util.function.BiFunction;
 #endif
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 import java.util.NoSuchElementException;
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
 
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -318,17 +324,17 @@ public class ARRAY_FIFO_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEUE K
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0,m=size();i<m;i++) {
 			int index = (first + i) % array.length;
 			if(filter.test(array[index])) {
 				KEY_TYPE data = array[index];
 				removeIndex(index);
-				return data;
+				return OPTIONAL.GET_OPTIONAL(data);
 			}
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -355,7 +361,7 @@ public class ARRAY_FIFO_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEUE K
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -367,7 +373,7 @@ public class ARRAY_FIFO_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEUE K
 			}
 			state = operator.APPLY_VALUE(state, array[(first + i) % array.length]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override

src/builder/resources/speiger/assets/collections/templates/queues/ArrayPriorityQueue.template

@@ -8,12 +8,18 @@ import java.util.function.Consumer;
 import java.util.function.BiFunction;
 #endif
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
 
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -346,7 +352,7 @@ public class ARRAY_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -358,20 +364,20 @@ public class ARRAY_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUE
 			}
 			state = operator.APPLY_VALUE(state, array[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0;i<size;i++) {
 			if(filter.test(array[i])) {
 				KEY_TYPE data = array[i];
 				removeIndex(i);
-				return data;
+				return OPTIONAL.GET_OPTIONAL(data);
 			}
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override

src/builder/resources/speiger/assets/collections/templates/queues/HeapPriorityQueue.template

@@ -8,12 +8,18 @@ import java.util.function.Consumer;
 import java.util.function.BiFunction;
 #endif
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
 
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -326,7 +332,7 @@ public class HEAP_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEU
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -338,20 +344,20 @@ public class HEAP_PRIORITY_QUEUE KEY_GENERIC_TYPE extends ABSTRACT_PRIORITY_QUEU
 			}
 			state = operator.APPLY_VALUE(state, array[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0;i<size;i++) {
 			if(filter.test(array[i])) {
 				KEY_TYPE data = array[i];
 				removeIndex(i);
-				return data;
+				return OPTIONAL.GET_OPTIONAL(data);
 			}
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override

src/builder/resources/speiger/assets/collections/templates/sets/AVLTreeSet.template

@@ -10,6 +10,9 @@ import java.util.function.BiFunction;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
@@ -19,6 +22,9 @@ import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -405,12 +411,12 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(Entry KEY_GENERIC_TYPE entry = first;entry != null;entry = entry.next()) {
-			if(filter.test(entry.key)) return entry.key;
+			if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -437,7 +443,7 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -449,7 +455,7 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 			}
 			state = operator.APPLY_VALUE(state, entry.key);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -1314,7 +1320,7 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1326,16 +1332,16 @@ public class AVL_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 				}
 				state = operator.APPLY_VALUE(state, entry.key);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Entry KEY_GENERIC_TYPE entry = start();entry != null && inRange(entry.key);entry = next(entry)) {
-				if(filter.test(entry.key)) return entry.key;
+				if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
 			}
-			return EMPTY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override

src/builder/resources/speiger/assets/collections/templates/sets/AbstractSet.template

@@ -6,6 +6,7 @@ import java.util.Objects;
 import java.util.Set;
 
 import speiger.src.collections.PACKAGE.collections.ABSTRACT_COLLECTION;
+import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 
 /**
@@ -47,4 +48,105 @@ public abstract class ABSTRACT_SET KEY_GENERIC_TYPE extends ABSTRACT_COLLECTION
 			return false;
 		}
 	}
+	
+#if ORDERED_SET_FEATURE
+	public static class REVERSED_ORDERED_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE implements ORDERED_SET KEY_GENERIC_TYPE {
+		protected ORDERED_SET KEY_GENERIC_TYPE set;
+		
+		public REVERSED_ORDERED_SET(ORDERED_SET KEY_GENERIC_TYPE set) {
+			this.set = set;
+		}
+		
+		@Override
+		public REVERSED_ORDERED_SET KEY_GENERIC_TYPE copy() { throw new UnsupportedOperationException(); }
+		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) {
+			return set.iterator(fromElement);
+		}
+		
+		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE iterator() {
+			return set.reverseIterator();
+		}
+		
+		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+			return set.iterator();
+		}
+		
+		@Override
+		public void addFirst(KEY_TYPE o) {
+			set.addLast(o);
+		}
+		
+		@Override
+		public void addLast(KEY_TYPE o) {
+			set.addFirst(o);
+		}
+		
+		@Override
+#if !TYPE_OBJECT
+		public boolean remove(KEY_TYPE o) {
+#else
+		public boolean remove(Object o) {
+#endif
+			return set.remove(o);
+		}
+		
+		@Override
+		public boolean add(KEY_TYPE o) {
+			return set.add(o);
+		}
+		
+		@Override
+		public boolean addAndMoveToFirst(KEY_TYPE o) {
+			return set.addAndMoveToLast(o);
+		}
+		
+		@Override
+		public boolean addAndMoveToLast(KEY_TYPE o) {
+			return set.addAndMoveToFirst(o);
+		}
+		
+		@Override
+		public boolean moveToFirst(KEY_TYPE o) {
+			return set.moveToLast(o);
+		}
+		
+		@Override
+		public boolean moveToLast(KEY_TYPE o) {
+			return set.moveToFirst(o);
+		}
+		
+		@Override
+		public KEY_TYPE GET_FIRST_KEY() {
+			return set.GET_LAST_KEY();
+		}
+		
+		@Override
+		public KEY_TYPE REMOVE_FIRST_KEY() {
+			return set.REMOVE_LAST_KEY();
+		}
+		
+		@Override
+		public KEY_TYPE GET_LAST_KEY() {
+			return set.GET_FIRST_KEY();
+		}
+		
+		@Override
+		public KEY_TYPE REMOVE_LAST_KEY() {
+			return set.REMOVE_FIRST_KEY();
+		}
+		
+		@Override
+		public ORDERED_SET KEY_GENERIC_TYPE reversed() {
+			return set;
+		}
+		
+		@Override
+		public int size() {
+			return set.size();
+		}
+	}
+#endif
 }

src/builder/resources/speiger/assets/collections/templates/sets/ArraySet.template

@@ -8,6 +8,9 @@ import java.util.function.BiFunction;
 #endif
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 import java.util.Set;
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
@@ -18,7 +21,9 @@ import java.util.function.JAVA_PREDICATE;
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
-
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -148,6 +153,25 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	}
 	
 #endif
+	@Override
+	public void addFirst(KEY_TYPE o) {
+		int index = findIndex(o);
+		if(index == -1) {
+			if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
+			System.arraycopy(data, 0, data, 1, size++);
+			data[0] = o;
+		}
+	}
+	
+	@Override
+	public void addLast(KEY_TYPE o) {
+		int index = findIndex(o);
+		if(index == -1) {
+			if(data.length == size) data = Arrays.copyOf(data, size == 0 ? 2 : size * 2);
+			data[size++] = o;
+		}
+	}
+	
 	@Override
 	public boolean addAndMoveToFirst(KEY_TYPE o) {
 		int index = findIndex(o);
@@ -219,13 +243,13 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	
 #endif
 	@Override
-	public KEY_TYPE FIRST_KEY() {
+	public KEY_TYPE GET_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return data[0];
 	}
 	
 	@Override
-	public KEY_TYPE LAST_KEY() {
+	public KEY_TYPE GET_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return data[size - 1];
 	}
@@ -354,7 +378,7 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	
 #endif
 	@Override
-	public KEY_TYPE POLL_FIRST_KEY() {
+	public KEY_TYPE REMOVE_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		KEY_TYPE result = data[0];
 		System.arraycopy(data, 1, data, 0, --size);
@@ -365,7 +389,7 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	}
 	
 	@Override
-	public KEY_TYPE POLL_LAST_KEY() {
+	public KEY_TYPE REMOVE_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		size--;
 #if TYPE_OBJECT
@@ -438,12 +462,12 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(int i = 0;i<size;i++) {
-			if(filter.test(data[i])) return data[i];
+			if(filter.test(data[i])) return OPTIONAL.GET_OPTIONAL(data[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 #if !TYPE_OBJECT
@@ -470,7 +494,7 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -482,7 +506,7 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 			}
 			state = operator.APPLY_VALUE(state, data[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
@@ -511,13 +535,18 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	
 	@Override
 	public BI_ITERATOR KEY_GENERIC_TYPE iterator() {
-		return new SetIterator(0);
+		return new SetIterator(true, 0);
+	}
+	
+	@Override
+	public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+		return new SetIterator(false, size);
 	}
 	
 	@Override
 	public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) {
 		int index = findIndex(fromElement);
-		if(index != -1) return new SetIterator(index);
+		if(index != -1) return new SetIterator(true, index);
 		throw new NoSuchElementException();
 	}
 	
@@ -570,45 +599,57 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 	}
 		
 	private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		boolean forward;
 		int index;
 		int lastReturned = -1;
 		
-		public SetIterator(int index) {
+		public SetIterator(boolean forward, int index) {
+			this.forward = forward;
 			this.index = index;
 		}
 		
 		@Override
 		public boolean hasNext() {
-			return index < size();
+			return forward ? index < size() : index > 0;
 		}
 		
 		@Override
 		public KEY_TYPE NEXT() {
 			if(!hasNext()) throw new NoSuchElementException();
+			if(forward) {
 				lastReturned = index;
 				return data[index++];				
 			}
+			index--;
+			return data[(lastReturned = index)];
+		}
 		
 		@Override
 		public boolean hasPrevious() {
-			return index > 0;
+			return forward ? index > 0 : index < size();
 		}
 		
 		@Override
 		public KEY_TYPE PREVIOUS() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			--index;
+			if(forward) {
+				index--;
 				return data[(lastReturned = index)];
 			}
+			lastReturned = index;
+			return data[index++];
+		}
 		
 		@Override
 		public int nextIndex() {
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		@Override
 		public int previousIndex() {
-			return index-1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		@Override
@@ -637,15 +678,23 @@ public class ARRAY_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE im
 		@Override
 		public int skip(int amount) {
 			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+			return forward ? moveForward(amount) : moveBackwards(amount);
+		}
+		
+		@Override
+		public int back(int amount) {
+			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+			return forward ? moveBackwards(amount) : moveForward(amount);
+		}
+		
+		private int moveForward(int amount) {
 			int steps = Math.min(amount, size() - index);
 			index += steps;
 			if(steps > 0) lastReturned = Math.min(index-1, size()-1);
 			return steps;
 		}
 		
-		@Override
-		public int back(int amount) {
-			if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+		private int moveBackwards(int amount) {
 			int steps = Math.min(amount, index);
 			index -= steps;
 			if(steps > 0) lastReturned = Math.min(index, size()-1);

src/builder/resources/speiger/assets/collections/templates/sets/ImmutableOpenHashSet.template

@@ -9,6 +9,9 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
@@ -19,6 +22,9 @@ import speiger.src.collections.PACKAGE.collections.ITERATOR;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -258,6 +264,10 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	@Override
 	public boolean addAll(COLLECTION KEY_GENERIC_TYPE c) { throw new UnsupportedOperationException(); }
 	@Override
+	public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+	@Override
+	public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+	@Override
 	public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 	@Override
 	public boolean addAndMoveToLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
@@ -285,22 +295,22 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	}
 	
 	@Override
-	public KEY_TYPE FIRST_KEY() {
+	public KEY_TYPE GET_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[firstIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_FIRST_KEY() { throw new UnsupportedOperationException(); }
+	public KEY_TYPE REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }
 	
 	@Override
-	public KEY_TYPE LAST_KEY() {
+	public KEY_TYPE GET_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[lastIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_LAST_KEY() { throw new UnsupportedOperationException(); }
+	public KEY_TYPE REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
 	@Override
 	public boolean remove(Object o) { throw new UnsupportedOperationException(); }
 
@@ -414,7 +424,7 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -427,18 +437,18 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 			else state = operator.APPLY_VALUE(state, keys[index]);
 			index = (int)links[index];
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		int index = firstIndex;
 		while(index != -1) {
-			if(filter.test(keys[index])) return keys[index];
+			if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 			index = (int)links[index];
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -455,7 +465,12 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	
 	@Override
 	public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-		return new SetIterator();
+		return new SetIterator(true);
+	}
+	
+	@Override
+	public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+		return new SetIterator(false);
 	}
 	
 	@Override
@@ -521,16 +536,20 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 	}
 
 	private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
-		int index = 0;
+		int index = -1;
 		
-		SetIterator() {
-			next = firstIndex;
+		SetIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		SetIterator(KEY_TYPE from) {
+			this.forward = true;
 			if(KEY_EQUALS_NULL(from)) {
 				if(containsNull) {
 					next = (int) links[nullIndex];
@@ -559,48 +578,60 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 		
 		@Override
 		public int skip(int amount) {
-			int result = 0;
-			while(next != -1 && result != amount) {
-				current = previous = next;
-				next = (int)(links[current]);
-				result++;
-			}
+			int result = forward ? moveForward(amount) : moveBackwards(amount);
 			if(index >= 0) index+=result;
 			return result;
 		}
 		
 		@Override
 		public int back(int amount) {
+			int result = forward ? moveBackwards(amount) : moveForward(amount);
+			if(index >= 0) index-=result;
+			return result;
+		}
+		
+		private int moveForward(int amount) {
+			int result = 0;
+			while(next != -1 && result != amount) {
+				current = previous = next;
+				next = (int)(links[current]);
+				result++;
+			}
+			return result;
+		}
+		
+		private int moveBackwards(int amount) {
 			int result = 0;
 			while(previous != -1 && result != amount) {
 				current = next = previous;
 				previous = (int)(links[current] >> 32);
 				result++;
 			}
-			if(index >= 0) index-=result;
 			return result;
 		}
 		
 		@Override
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}
 
 		@Override
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		@Override
 		public int nextIndex() {
 			ensureIndexKnown();
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		@Override
 		public int previousIndex() {
 			ensureIndexKnown();
-			return index - 1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		@Override
@@ -609,8 +640,8 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 		@Override
 		public KEY_TYPE PREVIOUS() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = next = previous;
-			previous = (int)(links[current] >> 32);
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return keys[current];
 		}
@@ -618,12 +649,22 @@ public class IMMUTABLE_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERI
 		@Override
 		public KEY_TYPE NEXT() {
 			if(!hasNext()) throw new NoSuchElementException();
-			current = previous = next;
-			next = (int)(links[current]);
+			if(forward) moveForwards();
+			else moveBackwards();
 			if(index >= 0) index++;
 			return keys[current];
 		}
 		
+		private void moveBackwards() {
+			current = next = previous;
+			previous = (int)(links[current] >> 32);
+		}
+		
+		private void moveForwards() {
+			current = previous = next;
+			next = (int)(links[current]);
+		}
+		
 		private void ensureIndexKnown() {
 			if(index == -1) {
 				if(previous == -1) {

src/builder/resources/speiger/assets/collections/templates/sets/LinkedOpenCustomHashSet.template

@@ -9,6 +9,9 @@ import java.util.Objects;
 import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
@@ -18,6 +21,9 @@ import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 #endif
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.PACKAGE.lists.LIST_ITERATOR;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.utils.ITERATORS;
@@ -235,6 +241,46 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	}
 	
 #endif
+	@Override
+	public void addFirst(KEY_TYPE o) {
+		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
+			if(containsNull) return;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToFirstIndex(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(strategy.hashCode(o)) & mask;
+			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
+				if(strategy.equals(keys[pos], o)) return;
+				pos = ++pos & mask;
+			}
+			keys[pos] = o;
+			onNodeAdded(pos);
+			moveToFirstIndex(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+	}
+	
+	@Override
+	public void addLast(KEY_TYPE o) {
+		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
+			if(containsNull) return;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(strategy.hashCode(o)) & mask;
+			while(!strategy.equals(keys[pos], EMPTY_KEY_VALUE)) {
+				if(strategy.equals(keys[pos], o)) return;
+				pos = ++pos & mask;
+			}
+			keys[pos] = o;
+			onNodeAdded(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+	}
+	
 	@Override
 	public boolean addAndMoveToFirst(KEY_TYPE o) {
 		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
@@ -291,7 +337,7 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	
 	@Override
 	public boolean moveToFirst(KEY_TYPE o) {
-		if(isEmpty() || strategy.equals(FIRST_KEY(), o)) return false;
+		if(isEmpty() || strategy.equals(GET_FIRST_KEY(), o)) return false;
 		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
 			if(containsNull) {
 				moveToFirstIndex(nullIndex);
@@ -313,7 +359,7 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	
 	@Override
 	public boolean moveToLast(KEY_TYPE o) {
-		if(isEmpty() || strategy.equals(LAST_KEY(), o)) return false;
+		if(isEmpty() || strategy.equals(GET_LAST_KEY(), o)) return false;
 		if(strategy.equals(o, EMPTY_KEY_VALUE)) {
 			if(containsNull) {
 				moveToLastIndex(nullIndex);
@@ -370,13 +416,13 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	}
 	
 	@Override
-	public KEY_TYPE FIRST_KEY() {
+	public KEY_TYPE GET_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[firstIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_FIRST_KEY() {
+	public KEY_TYPE REMOVE_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		int pos = firstIndex;
 		onNodeRemoved(pos);
@@ -392,13 +438,13 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	}
 	
 	@Override
-	public KEY_TYPE LAST_KEY() {
+	public KEY_TYPE GET_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[lastIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_LAST_KEY() {
+	public KEY_TYPE REMOVE_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		int pos = lastIndex;
 		onNodeRemoved(pos);
@@ -656,7 +702,7 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -669,18 +715,18 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 			else state = operator.APPLY_VALUE(state, keys[index]);
 			index = (int)links[index];
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		int index = firstIndex;
 		while(index != -1) {
-			if(filter.test(keys[index])) return keys[index];
+			if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 			index = (int)links[index];
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -697,7 +743,12 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	
 	@Override
 	public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-		return new SetIterator();
+		return new SetIterator(true);
+	}
+	
+	@Override
+	public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+		return new SetIterator(false);
 	}
 	
 	@Override
@@ -722,16 +773,20 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 	}
 	
 	private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
-		int index = 0;
+		int index = -1;
 		
-		SetIterator() {
-			next = firstIndex;
+		SetIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		SetIterator(KEY_TYPE from) {
+			this.forward = true;
 			if(strategy.equals(from, EMPTY_KEY_VALUE)) {
 				if(containsNull) {
 					next = (int) links[nullIndex];
@@ -760,48 +815,60 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 		
 		@Override
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}
 
 		@Override
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		@Override
 		public int skip(int amount) {
-			int result = 0;
-			while(next != -1 && result != amount) {
-				current = previous = next;
-				next = (int)(links[current]);
-				result++;
-			}
+			int result = forward ? moveForward(amount) : moveBackwards(amount);
 			if(index >= 0) index+=result;
 			return result;
 		}
 		
 		@Override
 		public int back(int amount) {
+			int result = forward ? moveBackwards(amount) : moveForward(amount);
+			if(index >= 0) index-=result;
+			return result;
+		}
+		
+		private int moveForward(int amount) {
+			int result = 0;
+			while(next != -1 && result != amount) {
+				current = previous = next;
+				next = (int)(links[current]);
+				result++;
+			}
+			return result;
+		}
+		
+		private int moveBackwards(int amount) {
 			int result = 0;
 			while(previous != -1 && result != amount) {
 				current = next = previous;
 				previous = (int)(links[current] >> 32);
 				result++;
 			}
-			if(index >= 0) index-=result;
 			return result;
 		}
 		
 		@Override
 		public int nextIndex() {
 			ensureIndexKnown();
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		@Override
 		public int previousIndex() {
 			ensureIndexKnown();
-			return index - 1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		@Override
@@ -850,8 +917,8 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 		@Override
 		public KEY_TYPE PREVIOUS() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = next = previous;
-			previous = (int)(links[current] >> 32);
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return keys[current];
 		}
@@ -859,12 +926,22 @@ public class LINKED_CUSTOM_HASH_SET KEY_GENERIC_TYPE extends CUSTOM_HASH_SET KEY
 		@Override
 		public KEY_TYPE NEXT() {
 			if(!hasNext()) throw new NoSuchElementException();
-			current = previous = next;
-			next = (int)(links[current]);
+			if(forward) moveForwards();
+			else moveBackwards();
 			if(index >= 0) index++;
 			return keys[current];
 		}
 		
+		private void moveBackwards() {
+			current = next = previous;
+			previous = (int)(links[current] >> 32);
+		}
+		
+		private void moveForwards() {
+			current = previous = next;
+			next = (int)(links[current]);
+		}
+		
 		private void ensureIndexKnown() {
 			if(index == -1) {
 				if(previous == -1) {

src/builder/resources/speiger/assets/collections/templates/sets/LinkedOpenHashSet.template

@@ -5,6 +5,9 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if TYPE_OBJECT
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
@@ -21,6 +24,9 @@ import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -206,6 +212,46 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	}
 	
 #endif
+	@Override
+	public void addFirst(KEY_TYPE o) {
+		if(KEY_EQUALS_NULL(o)) {
+			if(containsNull) return;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+			moveToFirstIndex(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(KEY_TO_HASH(o)) & mask;
+			while(KEY_EQUALS_NOT_NULL(keys[pos])) {
+				if(KEY_EQUALS(keys[pos], o)) return;
+				pos = ++pos & mask;
+			}
+			keys[pos] = o;
+			onNodeAdded(pos);
+			moveToFirstIndex(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+	}
+	
+	@Override
+	public void addLast(KEY_TYPE o) {
+		if(KEY_EQUALS_NULL(o)) {
+			if(containsNull) return;
+			containsNull = true;
+			onNodeAdded(nullIndex);
+		}
+		else {
+			int pos = HashUtil.mix(KEY_TO_HASH(o)) & mask;
+			while(KEY_EQUALS_NOT_NULL(keys[pos])) {
+				if(KEY_EQUALS(keys[pos], o)) return;
+				pos = ++pos & mask;
+			}
+			keys[pos] = o;
+			onNodeAdded(pos);
+		}
+		if(size++ >= maxFill) rehash(HashUtil.arraySize(size+1, loadFactor));
+	}
+	
 	@Override
 	public boolean addAndMoveToFirst(KEY_TYPE o) {
 		if(KEY_EQUALS_NULL(o)) {
@@ -262,7 +308,7 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	
 	@Override
 	public boolean moveToFirst(KEY_TYPE o) {
-		if(isEmpty() || KEY_EQUALS(FIRST_KEY(), o)) return false;
+		if(isEmpty() || KEY_EQUALS(GET_FIRST_KEY(), o)) return false;
 		if(KEY_EQUALS_NULL(o)) {
 			if(containsNull) {
 				moveToFirstIndex(nullIndex);
@@ -284,7 +330,7 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	
 	@Override
 	public boolean moveToLast(KEY_TYPE o) {
-		if(isEmpty() || KEY_EQUALS(LAST_KEY(), o)) return false;
+		if(isEmpty() || KEY_EQUALS(GET_LAST_KEY(), o)) return false;
 		if(KEY_EQUALS_NULL(o)) {
 			if(containsNull) {
 				moveToLastIndex(nullIndex);
@@ -341,13 +387,13 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE FIRST_KEY() {
+	public KEY_TYPE GET_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[firstIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_FIRST_KEY() {
+	public KEY_TYPE REMOVE_FIRST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		int pos = firstIndex;
 		onNodeRemoved(pos);
@@ -363,13 +409,13 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	}
 	
 	@Override
-	public KEY_TYPE LAST_KEY() {
+	public KEY_TYPE GET_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		return keys[lastIndex];
 	}
 	
 	@Override
-	public KEY_TYPE POLL_LAST_KEY() {
+	public KEY_TYPE REMOVE_LAST_KEY() {
 		if(size == 0) throw new NoSuchElementException();
 		int pos = lastIndex;
 		onNodeRemoved(pos);
@@ -511,7 +557,7 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -524,18 +570,18 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 			else state = operator.APPLY_VALUE(state, keys[index]);
 			index = (int)links[index];
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		int index = firstIndex;
 		while(index != -1) {
-			if(filter.test(keys[index])) return keys[index];
+			if(filter.test(keys[index])) return OPTIONAL.GET_OPTIONAL(keys[index]);
 			index = (int)links[index];
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -668,7 +714,12 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	
 	@Override
 	public LIST_ITERATOR KEY_GENERIC_TYPE iterator() {
-		return new SetIterator();
+		return new SetIterator(true);
+	}
+	
+	@Override
+	public LIST_ITERATOR KEY_GENERIC_TYPE reverseIterator() {
+		return new SetIterator(false);
 	}
 	
 	@Override
@@ -693,16 +744,20 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 	}
 	
 	private class SetIterator implements LIST_ITERATOR KEY_GENERIC_TYPE {
+		boolean forward;
 		int previous = -1;
 		int next = -1;
 		int current = -1;
-		int index = 0;
+		int index = -1;
 		
-		SetIterator() {
-			next = firstIndex;
+		SetIterator(boolean start) {
+			this.forward = start;
+			if(start) next = firstIndex;
+			else previous = lastIndex;
 		}
 		
 		SetIterator(KEY_TYPE from) {
+			this.forward = true;
 			if(KEY_EQUALS_NULL(from)) {
 				if(containsNull) {
 					next = (int) links[nullIndex];
@@ -731,48 +786,60 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 		
 		@Override
 		public int skip(int amount) {
-			int result = 0;
-			while(next != -1 && result != amount) {
-				current = previous = next;
-				next = (int)(links[current]);
-				result++;
-			}
+			int result = forward ? moveForward(amount) : moveBackwards(amount);
 			if(index >= 0) index+=result;
 			return result;
 		}
 		
 		@Override
 		public int back(int amount) {
+			int result = forward ? moveBackwards(amount) : moveForward(amount);
+			if(index >= 0) index-=result;
+			return result;
+		}
+		
+		private int moveForward(int amount) {
+			int result = 0;
+			while(next != -1 && result != amount) {
+				current = previous = next;
+				next = (int)(links[current]);
+				result++;
+			}
+			return result;
+		}
+		
+		private int moveBackwards(int amount) {
 			int result = 0;
 			while(previous != -1 && result != amount) {
 				current = next = previous;
 				previous = (int)(links[current] >> 32);
 				result++;
 			}
-			if(index >= 0) index-=result;
 			return result;
 		}
 		
 		@Override
 		public boolean hasNext() {
-			return next != -1;
+			return (forward ? next : previous) != -1;
 		}
 
 		@Override
 		public boolean hasPrevious() {
-			return previous != -1;
+			return (forward ? previous : next) != -1;
 		}
 		
 		@Override
 		public int nextIndex() {
 			ensureIndexKnown();
-			return index;
+			if(forward) return index;
+			return size - index;
 		}
 		
 		@Override
 		public int previousIndex() {
 			ensureIndexKnown();
-			return index - 1;
+			if(forward) return index-1;
+			return (size - index)-1;
 		}
 		
 		@Override
@@ -821,8 +888,8 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 		@Override
 		public KEY_TYPE PREVIOUS() {
 			if(!hasPrevious()) throw new NoSuchElementException();
-			current = next = previous;
-			previous = (int)(links[current] >> 32);
+			if(forward) moveBackwards();
+			else moveForwards();
 			if(index >= 0) index--;
 			return keys[current];
 		}
@@ -830,12 +897,22 @@ public class LINKED_HASH_SET KEY_GENERIC_TYPE extends HASH_SET KEY_GENERIC_TYPE
 		@Override
 		public KEY_TYPE NEXT() {
 			if(!hasNext()) throw new NoSuchElementException();
-			current = previous = next;
-			next = (int)(links[current]);
+			if(forward) moveForwards();
+			else moveBackwards();
 			if(index >= 0) index++;
 			return keys[current];
 		}
 		
+		private void moveBackwards() {
+			current = next = previous;
+			previous = (int)(links[current] >> 32);
+		}
+		
+		private void moveForwards() {
+			current = previous = next;
+			next = (int)(links[current]);
+		}
+		
 		private void ensureIndexKnown() {
 			if(index == -1) {
 				if(previous == -1) {

src/builder/resources/speiger/assets/collections/templates/sets/NavigableSet.template

@@ -3,11 +3,13 @@ package speiger.src.collections.PACKAGE.sets;
 import java.util.NavigableSet;
 
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 #if SETS_FEATURE
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
-import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
 
 /**
  * A Type Specific Navigable Set interface with a couple helper methods
@@ -145,6 +147,7 @@ public interface NAVIGABLE_SET KEY_GENERIC_TYPE extends NavigableSet<CLASS_TYPE>
 	public default NAVIGABLE_SET KEY_GENERIC_TYPE unmodifiable() { return SETS.unmodifiable(this); }
 	
 #endif
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
@@ -152,6 +155,7 @@ public interface NAVIGABLE_SET KEY_GENERIC_TYPE extends NavigableSet<CLASS_TYPE>
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
 	
+#endif
 #if !TYPE_OBJECT
 	@Override
 	@Deprecated

src/builder/resources/speiger/assets/collections/templates/sets/OpenCustomHashSet.template

@@ -6,6 +6,9 @@ import java.util.ConcurrentModificationException;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if TYPE_OBJECT
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
@@ -16,6 +19,9 @@ import java.util.function.PREDICATE;
 
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.utils.ITERATORS;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -635,7 +641,7 @@ public class CUSTOM_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_T
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -652,18 +658,18 @@ public class CUSTOM_HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_T
 			}
 			state = operator.APPLY_VALUE(state, keys[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
-		if(size() <= 0) return EMPTY_VALUE;
-		if(containsNull && filter.test(keys[nullIndex])) return keys[nullIndex];
+		if(size() <= 0) return OPTIONAL.empty();
+		if(containsNull && filter.test(keys[nullIndex])) return OPTIONAL.GET_OPTIONAL(keys[nullIndex]);
 		for(int i = nullIndex-1;i>=0;i--) {
-			if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(keys[i])) return keys[i];
+			if(!strategy.equals(keys[i], EMPTY_KEY_VALUE) && filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override

src/builder/resources/speiger/assets/collections/templates/sets/OpenHashSet.template

@@ -6,6 +6,9 @@ import java.util.ConcurrentModificationException;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if TYPE_OBJECT
 import java.util.function.Consumer;
 import java.util.function.BiFunction;
@@ -20,6 +23,9 @@ import speiger.src.collections.PACKAGE.collections.ITERATOR;
 import speiger.src.collections.PACKAGE.utils.ITERATORS;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -498,7 +504,7 @@ public class HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE imp
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -515,18 +521,18 @@ public class HASH_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE imp
 			}
 			state = operator.APPLY_VALUE(state, keys[i]);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
-		if(size() <= 0) return EMPTY_VALUE;
-		if(containsNull && filter.test(keys[nullIndex])) return keys[nullIndex];
+		if(size() <= 0) return OPTIONAL.empty();
+		if(containsNull && filter.test(keys[nullIndex])) return OPTIONAL.GET_OPTIONAL(keys[nullIndex]);
 		for(int i = nullIndex-1;i>=0;i--) {
-			if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(keys[i])) return keys[i];
+			if(KEY_EQUALS_NOT_NULL(keys[i]) && filter.test(keys[i])) return OPTIONAL.GET_OPTIONAL(keys[i]);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override

src/builder/resources/speiger/assets/collections/templates/sets/OrderedSet.template

@@ -1,11 +1,19 @@
 package speiger.src.collections.PACKAGE.sets;
 
+#if JAVA_VERSION>=21
+import java.util.SequencedSet;
+
+#endif
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
+import speiger.src.collections.PACKAGE.collections.ORDERED_COLLECTION;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
+import speiger.src.collections.PACKAGE.sets.ABSTRACT_SET.REVERSED_ORDERED_SET;
 #if SETS_FEATURE
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
-import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
 
 /**
  * A Special Set Interface giving Access to some really usefull functions
@@ -15,7 +23,11 @@ import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
  * 
  * @Type(T)
  */
-public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE
+#if JAVA_VERSION>=21
+public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE, ORDERED_COLLECTION KEY_GENERIC_TYPE, SequencedSet<CLASS_TYPE>
+#else
+public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE, ORDERED_COLLECTION KEY_GENERIC_TYPE
+#endif
 {
 	/**
 	 * A customized add method that allows you to insert into the first index.
@@ -52,6 +64,7 @@ public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE
 	
 	@Override
 	public BI_ITERATOR KEY_GENERIC_TYPE iterator();
+	public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator();
 	
 	/**
 	 * A type Specific Iterator starting from a given key
@@ -61,6 +74,7 @@ public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE
 	 */
 	public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement);
 	
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
@@ -68,26 +82,80 @@ public interface ORDERED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
 	
+#endif
 	/**
 	 * A method to get the first element in the set
 	 * @return first element in the set
 	 */
-	public KEY_TYPE FIRST_KEY();
+	public KEY_TYPE GET_FIRST_KEY();
 	/**
 	 * A method to get and remove the first element in the set
 	 * @return first element in the set
 	 */
-	public KEY_TYPE POLL_FIRST_KEY();
+	public KEY_TYPE REMOVE_FIRST_KEY();
 	/**
 	 * A method to get the last element in the set
 	 * @return last element in the set
 	 */
-	public KEY_TYPE LAST_KEY();
+	public KEY_TYPE GET_LAST_KEY();
 	/**
 	 * A method to get and remove the last element in the set
 	 * @return last element in the set
 	 */
-	public KEY_TYPE POLL_LAST_KEY();
+	public KEY_TYPE REMOVE_LAST_KEY();
+	
+#if JAVA_VERSION>=21 && !TYPE_OBJECT
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void addFirst(CLASS_TYPE e) { addAndMoveToFirst(OBJ_TO_KEY(e)); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void addLast(CLASS_TYPE e) { addAndMoveToLast(OBJ_TO_KEY(e)); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default CLASS_TYPE getFirst() { return GET_FIRST_KEY(); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default CLASS_TYPE getLast() { return GET_LAST_KEY(); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeFirst() { return REMOVE_FIRST_KEY(); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default CLASS_TYPE removeLast() { return REMOVE_LAST_KEY(); }
+	
+#endif
+	@Java21
+	public default ORDERED_SET KEY_GENERIC_TYPE reversed() { return new REVERSED_ORDERED_SETBRACES(this); }
 
 #if SETS_FEATURE
 	/**

src/builder/resources/speiger/assets/collections/templates/sets/RBTreeSet.template

@@ -2,6 +2,9 @@ package speiger.src.collections.PACKAGE.sets;
 
 import java.util.Collection;
 import java.util.Collections;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if TYPE_OBJECT
 import java.util.Comparator;
 import java.util.function.Consumer;
@@ -19,6 +22,9 @@ import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 import speiger.src.collections.ints.functions.consumer.BI_FROM_INT_CONSUMER;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 #if !JDK_FUNCTION
@@ -427,7 +433,7 @@ public class RB_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 	
 #endif
 	@Override
-	public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+	public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 		Objects.requireNonNull(operator);
 		KEY_TYPE state = EMPTY_VALUE;
 		boolean empty = true;
@@ -439,16 +445,16 @@ public class RB_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 			}
 			state = operator.APPLY_VALUE(state, entry.key);
 		}
-		return state;
+		return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 	}
 	
 	@Override
-	public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+	public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 		Objects.requireNonNull(filter);
 		for(Entry KEY_GENERIC_TYPE entry = first;entry != null;entry = entry.next()) {
-			if(filter.test(entry.key)) return entry.key;
+			if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
 		}
-		return EMPTY_VALUE;
+		return OPTIONAL.empty();
 	}
 	
 	@Override
@@ -1374,7 +1380,7 @@ public class RB_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 		
 #endif
 		@Override
-		public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) {
 			Objects.requireNonNull(operator);
 			KEY_TYPE state = EMPTY_VALUE;
 			boolean empty = true;
@@ -1386,16 +1392,16 @@ public class RB_TREE_SET KEY_GENERIC_TYPE extends ABSTRACT_SET KEY_GENERIC_TYPE
 				}
 				state = operator.APPLY_VALUE(state, entry.key);
 			}
-			return state;
+			return empty ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(state);
 		}
 		
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) {
 			Objects.requireNonNull(filter);
 			for(Entry KEY_GENERIC_TYPE entry = start();entry != null && inRange(entry.key);entry = next(entry)) {
-				if(filter.test(entry.key)) return entry.key;
+				if(filter.test(entry.key)) return OPTIONAL.GET_OPTIONAL(entry.key);
 			}
-			return EMPTY_VALUE;
+			return OPTIONAL.empty();
 		}
 		
 		@Override

src/builder/resources/speiger/assets/collections/templates/sets/Set.template

@@ -4,11 +4,13 @@ import java.util.Set;
 
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 #if SETS_FEATURE
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
-import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
 
 
 /**
@@ -88,10 +90,12 @@ public interface SET KEY_GENERIC_TYPE extends Set<CLASS_TYPE>, COLLECTION KEY_GE
 	public default SET KEY_GENERIC_TYPE unmodifiable() { return SETS.unmodifiable(this); }
 	
 #endif
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
 	 */
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
+#endif
 }

src/builder/resources/speiger/assets/collections/templates/sets/SortedSet.template

@@ -3,7 +3,9 @@ package speiger.src.collections.PACKAGE.sets;
 import java.util.SortedSet;
 
 import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
+#endif
 #if TYPE_OBJECT
 import java.util.Comparator;
 #else
@@ -12,7 +14,9 @@ import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 #if SETS_FEATURE
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
+#if SPLIT_ITERATOR_FEATURE
 import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
+#endif
 
 /**
  * A Type Specific SortedSet implementation to reduce boxing/unboxing
@@ -67,6 +71,7 @@ public interface SORTED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE, Sorte
 	public default SORTED_SET KEY_GENERIC_TYPE unmodifiable() { return SETS.unmodifiable(this); }
 	
 #endif
+#if SPLIT_ITERATOR_FEATURE
 	/**
 	 * A Type Specific Type Splititerator to reduce boxing/unboxing
 	 * @return type specific splititerator
@@ -74,6 +79,7 @@ public interface SORTED_SET KEY_GENERIC_TYPE extends SET KEY_GENERIC_TYPE, Sorte
 	@Override
 	default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createSplititerator(this, 0); }
 	
+#endif
 #if !TYPE_OBJECT
 	/**
 	 * A Type Specific SubSet method to reduce boxing/unboxing

src/builder/resources/speiger/assets/collections/templates/utils/Collections.template

@@ -8,6 +8,9 @@ import java.util.ConcurrentModificationException;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Objects;
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 #if TYPE_OBJECT
 import java.util.Comparator;
 import java.util.function.BiFunction;
@@ -23,10 +26,16 @@ import java.util.function.Consumer;
 
 import speiger.src.collections.PACKAGE.collections.ABSTRACT_COLLECTION;
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
+#if ORDERED_MAP_FEATURE
+import speiger.src.collections.PACKAGE.collections.ORDERED_COLLECTION;
+#endif
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if !TYPE_OBJECT
 import speiger.src.collections.objects.utils.ObjectArrays;
 import speiger.src.collections.PACKAGE.functions.CONSUMER;
@@ -76,6 +85,37 @@ public class COLLECTIONS
 		return c instanceof UnmodifiableCollection ? c : new UnmodifiableCollectionBRACES(c);
 	}
 	
+	/**
+	 * Returns a Immutable Ordered Collection instance based on the instance given.
+	 * @param c that should be made immutable/unmodifiable
+	 * @Type(T)
+	 * @return a unmodifiable Ordered collection wrapper. If the Collection already a unmodifiable wrapper then it just returns itself.
+	 */
+	public static GENERIC_KEY_BRACES ORDERED_COLLECTION KEY_GENERIC_TYPE unmodifiable(ORDERED_COLLECTION KEY_GENERIC_TYPE c) {
+		return c instanceof UnmodifiableOrderedCollection ? c : new UnmodifiableOrderedCollectionBRACES(c);
+	}
+	
+	/**
+	 * Returns a synchronized ordered Collection instance based on the instance given.
+	 * @param c that should be synchronized
+	 * @Type(T)
+	 * @return a synchronized ordered collection wrapper. If the Collection already a synchronized wrapper then it just returns itself.
+	 */
+	public static GENERIC_KEY_BRACES ORDERED_COLLECTION KEY_GENERIC_TYPE synchronize(ORDERED_COLLECTION KEY_GENERIC_TYPE c) {
+		return c instanceof SynchronizedOrderedCollection ? c : new SynchronizedOrderedCollectionBRACES(c);
+	}
+	
+	/**
+	 * Returns a synchronized ordered Collection instance based on the instance given.
+	 * @param c that should be synchronized
+	 * @param mutex is the controller of the synchronization block.
+	 * @Type(T)
+	 * @return a synchronized ordered collection wrapper. If the Collection already a synchronized wrapper then it just returns itself.
+	 */
+	public static GENERIC_KEY_BRACES ORDERED_COLLECTION KEY_GENERIC_TYPE synchronize(ORDERED_COLLECTION KEY_GENERIC_TYPE c, Object mutex) {
+		return c instanceof SynchronizedOrderedCollection ? c : new SynchronizedOrderedCollectionBRACES(c, mutex);
+	}
+	
 	/**
 	 * Returns a synchronized Collection instance based on the instance given.
 	 * @param c that should be synchronized
@@ -668,6 +708,38 @@ public class COLLECTIONS
 		@Override
 		public SingletonCollection KEY_GENERIC_TYPE copy() { return new SingletonCollectionBRACES(element); }
 	}
+	/**
+	 * Synchronized Ordered Collection Wrapper for the synchronizedCollection function
+	 * @Type(T)
+	 */
+	public static class SynchronizedOrderedCollection KEY_GENERIC_TYPE extends SynchronizedCollection KEY_GENERIC_TYPE implements ORDERED_COLLECTION KEY_GENERIC_TYPE {
+		ORDERED_COLLECTION KEY_GENERIC_TYPE c;
+		
+		SynchronizedOrderedCollection(ORDERED_COLLECTION KEY_GENERIC_TYPE c, Object mutex) {
+			super(c, mutex);
+			this.c = c;
+		}
+		
+		SynchronizedOrderedCollection(ORDERED_COLLECTION KEY_GENERIC_TYPE c) {
+			super(c);
+			this.c = c;
+		}
+		
+		@Override
+		public ORDERED_COLLECTION KEY_GENERIC_TYPE reversed() { return COLLECTIONS.synchronize(c.reversed(), mutex); }
+		@Override
+		public void addFirst(KEY_TYPE e) { synchronized(mutex) { this.c.addFirst(e); } }
+		@Override
+		public void addLast(KEY_TYPE e) { synchronized(mutex) { this.c.addLast(e); } }
+		@Override
+		public KEY_TYPE GET_FIRST_KEY() { synchronized(mutex) { return this.c.GET_FIRST_KEY(); } }
+		@Override
+		public KEY_TYPE REMOVE_FIRST_KEY() { synchronized(mutex) { return this.c.REMOVE_FIRST_KEY(); } }
+		@Override
+		public KEY_TYPE GET_LAST_KEY() { synchronized(mutex) { return this.c.GET_LAST_KEY(); } }
+		@Override
+		public KEY_TYPE REMOVE_LAST_KEY() { synchronized(mutex) { return this.c.REMOVE_LAST_KEY(); } }
+	}	
 	
 	/**
 	 * Synchronized Collection Wrapper for the synchronizedCollection function
@@ -803,13 +875,41 @@ public class COLLECTIONS
 		public KEY_TYPE reduce(KEY_TYPE identity, UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return c.reduce(identity, operator); } }
 #endif
 		@Override
-		public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return c.reduce(operator); } }
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return c.reduce(operator); } }
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return c.findFirst(filter); } }
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return c.findFirst(filter); } }
 		@Override
 		public int count(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return c.count(filter); } }
 	}
 	
+	/**
+	 * Unmodifyable Ordered Collection Wrapper for the unmodifyableCollection method
+	 * @Type(T)
+	 */
+	public static class UnmodifiableOrderedCollection KEY_GENERIC_TYPE extends UnmodifiableCollection KEY_GENERIC_TYPE implements ORDERED_COLLECTION KEY_GENERIC_TYPE {
+		ORDERED_COLLECTION KEY_GENERIC_TYPE c;
+		
+		UnmodifiableOrderedCollection(ORDERED_COLLECTION KEY_GENERIC_TYPE c) {
+			super(c);
+			this.c = c;
+		}
+		
+		@Override
+		public ORDERED_COLLECTION KEY_GENERIC_TYPE reversed() { return COLLECTIONS.unmodifiable(c.reversed()); }
+		@Override
+		public void addFirst(KEY_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(KEY_TYPE e) { throw new UnsupportedOperationException(); }
+		@Override
+		public KEY_TYPE GET_FIRST_KEY() { return c.GET_FIRST_KEY(); }
+		@Override
+		public KEY_TYPE REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }
+		@Override
+		public KEY_TYPE GET_LAST_KEY() { return c.GET_LAST_KEY(); }
+		@Override
+		public KEY_TYPE REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
+	}
+	
 	/**
 	 * Unmodifyable Collection Wrapper for the unmodifyableCollection method
 	 * @Type(T)
@@ -927,9 +1027,9 @@ public class COLLECTIONS
 		public KEY_TYPE reduce(KEY_TYPE identity, UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { return c.reduce(identity, operator); }
 #endif
 		@Override
-		public KEY_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { return c.reduce(operator); }
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { return c.reduce(operator); }
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { return c.findFirst(filter); }
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { return c.findFirst(filter); }
 		@Override
 		public int count(PREDICATE KEY_GENERIC_TYPE filter) { return c.count(filter); }
 	}

src/builder/resources/speiger/assets/collections/templates/utils/Iterables.template

@@ -342,6 +342,8 @@ public class ITERABLES
 #argument MAPPER Predicate ToByteFunction ToShortFunction ToIntFunction ToLongFunction ToFloatFunction ToDoubleFunction
 #argument APPLY test applyAsByte applyAsShort applyAsInt applyAsLong applyAsFloat applyAsDouble
 #argument DATA_TYPE Boolean Byte Short Int Long Float Double
+#argument FILTER_TYPE BOOLEAN_COLLECTION_MODULE BYTE_COLLECTION_MODULE SHORT_COLLECTION_MODULE INT_COLLECTION_MODULE LONG_COLLECTION_MODULE FLOAT_COLLECTION_MODULE DOUBLE_COLLECTION_MODULE
+#if FILTER_TYPE
 	private static class MAPPED_TYPEIterable<E> implements OUTPUT_ITERABLE, ISizeProvider
 	{
 		ITERABLE KEY_SPECIAL_GENERIC_TYPE<E> iterable;
@@ -369,6 +371,7 @@ public class ITERABLES
 		}
 	}
 	
+#endif
 #enditerate
 #endif
 	private static class MappedIterable KSS_GENERIC_TYPE<E, T> implements ObjectIterable<T>, ISizeProvider

src/builder/resources/speiger/assets/collections/templates/utils/Iterators.template

@@ -25,7 +25,7 @@ import speiger.src.collections.booleans.collections.BooleanIterator;
 #argument PACKAGE bytes shorts ints longs floats doubles
 #argument MAPPER ToByteFunction ToShortFunction ToIntFunction ToLongFunction ToFloatFunction ToDoubleFunction
 #argument FILTER_TYPE BYTE_COLLECTION_MODULE SHORT_COLLECTION_MODULE INT_COLLECTION_MODULE LONG_COLLECTION_MODULE FLOAT_COLLECTION_MODULE DOUBLE_COLLECTION_MODULE
-#if BOOLEAN_COLLECTION_MODULE
+#if FILTER_TYPE
 import speiger.src.collections.objects.functions.function.MAPPER;
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 #endif
@@ -65,7 +65,7 @@ public class ITERATORS
 	 * @Type(T)
 	 * @return an empty iterator
 	 */
-	public static GENERIC_KEY_BRACES EmptyIterator KEY_GENERIC_TYPE empty() {
+	public static GENERIC_KEY_BRACES LIST_ITERATOR KEY_GENERIC_TYPE empty() {
 #if TYPE_OBJECT
 		return (EmptyIterator<KEY_TYPE>)EMPTY;
 #else
@@ -400,7 +400,7 @@ public class ITERATORS
 	 * @ArrayType(T)
 	 * @return a Iterator that is wrapping a array.
 	 */
-	public static GENERIC_KEY_BRACES ArrayIterator KEY_GENERIC_TYPE wrap(KEY_TYPE... a) {
+	public static GENERIC_KEY_BRACES ITERATOR KEY_GENERIC_TYPE wrap(KEY_TYPE... a) {
 		return wrap(a, 0, a.length);
 	}
 	
@@ -412,7 +412,7 @@ public class ITERATORS
 	 * @ArrayType(T)
 	 * @return a Iterator that is wrapping a array.
 	 */
-	public static GENERIC_KEY_BRACES ArrayIterator KEY_GENERIC_TYPE wrap(KEY_TYPE[] a, int start, int end) {
+	public static GENERIC_KEY_BRACES ITERATOR KEY_GENERIC_TYPE wrap(KEY_TYPE[] a, int start, int end) {
 		return new ArrayIteratorBRACES(a, start, end);
 	}
 	
@@ -925,6 +925,8 @@ public class ITERATORS
 #argument MAPPER Predicate ToByteFunction ToShortFunction ToIntFunction ToLongFunction ToFloatFunction ToDoubleFunction
 #argument APPLY test applyAsByte applyAsShort applyAsInt applyAsLong applyAsFloat applyAsDouble
 #argument DATA_TYPE boolean byte short int long float double
+#argument FILTER_TYPE BOOLEAN_COLLECTION_MODULE BYTE_COLLECTION_MODULE SHORT_COLLECTION_MODULE INT_COLLECTION_MODULE LONG_COLLECTION_MODULE FLOAT_COLLECTION_MODULE DOUBLE_COLLECTION_MODULE
+#if FILTER_TYPE
 	private static class MAPPED_TYPEIterator<E> implements OUTPUT_ITERATOR
 	{
 		ITERATOR<E> iterator;
@@ -951,6 +953,7 @@ public class ITERATORS
 		}
 	}
 	
+#endif
 #enditerate
 #endif
 	private static class FlatMappedIterator KSS_GENERIC_TYPE<E, T,[SPACE]V extends Iterable<T>> implements ObjectIterator<T>

src/builder/resources/speiger/assets/collections/templates/utils/Lists.template

@@ -45,7 +45,7 @@ public class LISTS
 	 * @Type(T)
 	 * @return an empty list
 	 */
-	public static GENERIC_KEY_BRACES EmptyList KEY_GENERIC_TYPE empty() {
+	public static GENERIC_KEY_BRACES LIST KEY_GENERIC_TYPE empty() {
 #if TYPE_OBJECT
 		return (EmptyList<KEY_TYPE>)EMPTY;
 #else

src/builder/resources/speiger/assets/collections/templates/utils/PriorityQueues.template

@@ -4,16 +4,22 @@ package speiger.src.collections.PACKAGE.utils;
 import java.util.Collection;
 import java.util.Comparator;
 import java.util.function.Consumer;
+import java.util.function.BiFunction;
 #endif
 #if JDK_FUNCTION
 import java.util.function.PREDICATE;
 #endif
-
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#endif
 import speiger.src.collections.PACKAGE.collections.ITERATOR;
 import speiger.src.collections.PACKAGE.collections.COLLECTION;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.functions.COMPARATOR;
 #endif
+#if !JDK_TYPE 
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
 #if DEQUEUE_FEATURE
 import speiger.src.collections.PACKAGE.queues.PRIORITY_DEQUEUE;
 #endif
@@ -24,6 +30,7 @@ import speiger.src.collections.PACKAGE.functions.CONSUMER;
 #if !JDK_FUNCTION
 import speiger.src.collections.PACKAGE.functions.function.PREDICATE;
 #endif
+import speiger.src.collections.PACKAGE.functions.function.UNARY_OPERATOR;
 import speiger.src.collections.objects.functions.consumer.BI_FROM_OBJECT_CONSUMER;
 
 /**
@@ -140,7 +147,15 @@ public class PRIORITY_QUEUES
 		@Override
 		public boolean matchesAll(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return queue.matchesAll(filter); } }
 		@Override
-		public KEY_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return queue.findFirst(filter); } }
+		public OPTIONAL KEY_GENERIC_TYPE findFirst(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return queue.findFirst(filter); } }
+		#if TYPE_OBJECT
+		public <KEY_SPECIAL_TYPE> KEY_SPECIAL_TYPE reduce(KEY_SPECIAL_TYPE identity, BiFunction<KEY_SPECIAL_TYPE, KEY_TYPE, KEY_SPECIAL_TYPE> operator) { synchronized(mutex) { return queue.reduce(identity, operator); } }
+#else
+		@Override
+		public KEY_TYPE reduce(KEY_TYPE identity, UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return queue.reduce(identity, operator); } }
+#endif
+		@Override
+		public OPTIONAL KEY_GENERIC_TYPE reduce(UNARY_OPERATOR KEY_KEY_GENERIC_TYPE operator) { synchronized(mutex) { return queue.reduce(operator); } }
 		@Override
 		public int count(PREDICATE KEY_GENERIC_TYPE filter) { synchronized(mutex) { return queue.count(filter); } }
 	}

src/builder/resources/speiger/assets/collections/templates/utils/Sets.template

@@ -360,6 +360,10 @@ public class SETS
 			s = c;
 		}
 		
+		@Override
+		public void addFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -371,17 +375,19 @@ public class SETS
 		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator() { return ITERATORS.unmodifiable(s.iterator()); }
 		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator() { return ITERATORS.unmodifiable(s.reverseIterator()); }
+		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) { return ITERATORS.unmodifiable(s.iterator(fromElement)); }
 		@Override
 		public ORDERED_SET KEY_GENERIC_TYPE copy() { return s.copy(); }
 		@Override
-		public KEY_TYPE FIRST_KEY() { return s.FIRST_KEY(); }
+		public KEY_TYPE GET_FIRST_KEY() { return s.GET_FIRST_KEY(); }
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() { throw new UnsupportedOperationException(); }
+		public KEY_TYPE REMOVE_FIRST_KEY() { throw new UnsupportedOperationException(); }
 		@Override
-		public KEY_TYPE LAST_KEY() { return s.LAST_KEY(); }
+		public KEY_TYPE GET_LAST_KEY() { return s.GET_LAST_KEY(); }
 		@Override
-		public KEY_TYPE POLL_LAST_KEY() { throw new UnsupportedOperationException(); }
+		public KEY_TYPE REMOVE_LAST_KEY() { throw new UnsupportedOperationException(); }
 	}
 	
 #endif
@@ -649,6 +655,10 @@ public class SETS
 			s = c;
 		}
 		
+		@Override
+		public void addFirst(KEY_TYPE o) { synchronized(mutex) { s.addFirst(o); } }
+		@Override
+		public void addLast(KEY_TYPE o) { synchronized(mutex) { s.addLast(o); } }
 		@Override
 		public boolean addAndMoveToFirst(KEY_TYPE o) { synchronized(mutex) { return s.addAndMoveToFirst(o); } }
 		@Override
@@ -660,17 +670,19 @@ public class SETS
 		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator() { synchronized(mutex) { return s.iterator(); } }
 		@Override
+		public BI_ITERATOR KEY_GENERIC_TYPE reverseIterator() { synchronized(mutex) { return s.reverseIterator(); } }
+		@Override
 		public BI_ITERATOR KEY_GENERIC_TYPE iterator(KEY_TYPE fromElement) { synchronized(mutex) { return s.iterator(fromElement); } }
 		@Override
 		public ORDERED_SET KEY_GENERIC_TYPE copy() { synchronized(mutex) { return s.copy(); } }
 		@Override
-		public KEY_TYPE FIRST_KEY() { synchronized(mutex) { return s.FIRST_KEY(); } }
+		public KEY_TYPE GET_FIRST_KEY() { synchronized(mutex) { return s.GET_FIRST_KEY(); } }
 		@Override
-		public KEY_TYPE POLL_FIRST_KEY() { synchronized(mutex) { return s.POLL_FIRST_KEY(); } }
+		public KEY_TYPE REMOVE_FIRST_KEY() { synchronized(mutex) { return s.REMOVE_FIRST_KEY(); } }
 		@Override
-		public KEY_TYPE LAST_KEY() { synchronized(mutex) { return s.LAST_KEY(); } }
+		public KEY_TYPE GET_LAST_KEY() { synchronized(mutex) { return s.GET_LAST_KEY(); } }
 		@Override
-		public KEY_TYPE POLL_LAST_KEY() { synchronized(mutex) { return s.POLL_LAST_KEY(); } }
+		public KEY_TYPE REMOVE_LAST_KEY() { synchronized(mutex) { return s.REMOVE_LAST_KEY(); } }
 	}
 	
 #endif

src/builder/resources/speiger/assets/collections/templates/utils/maps/Maps.template

@@ -56,6 +56,9 @@ import speiger.src.collections.PACKAGE.sets.SET;
 import speiger.src.collections.PACKAGE.utils.SETS;
 #endif
 import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_COLLECTION;
+#if ORDERED_MAP_FEATURE
+import speiger.src.collections.VALUE_PACKAGE.collections.VALUE_ORDERED_COLLECTION;
+#endif
 #if !SAME_TYPE
 import speiger.src.collections.VALUE_PACKAGE.functions.function.VALUE_UNARY_OPERATOR;
 #endif
@@ -553,6 +556,10 @@ public class MAPS
 		@Override
 		public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
 		@Override
+		public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
+		@Override
+		public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) { throw new UnsupportedOperationException(); }
+		@Override
 		public boolean moveToFirst(KEY_TYPE key) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean moveToLast(KEY_TYPE key) { throw new UnsupportedOperationException(); }
@@ -573,13 +580,25 @@ public class MAPS
 		@Override
 		public VALUE_TYPE LAST_ENTRY_VALUE() { return map.LAST_ENTRY_VALUE(); }
 		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() { return map.firstEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() { return map.lastEntry(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() { throw new UnsupportedOperationException(); }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() { throw new UnsupportedOperationException(); }
+		@Override
 		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE copy() { return map.copy(); }
 		@Override
 		public ORDERED_SET KEY_GENERIC_TYPE keySet() { 
 			if(keys == null) keys = SETS.unmodifiable(map.keySet()); 
 			return (ORDERED_SET KEY_GENERIC_TYPE)keys;
 		}
-				
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
+			if(values == null) values = VALUE_COLLECTIONS.unmodifiable(map.values());
+			return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)values;
+		}
 		@Override
 		public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 			if(entrySet == null) entrySet = new UnmodifyableOrderedEntrySetKV_BRACES(map.ENTRY_SET());
@@ -736,6 +755,10 @@ public class MAPS
 			set = c;
 		}
 		
+		@Override
+		public void addFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
+		@Override
+		public void addLast(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
 		public boolean addAndMoveToFirst(MAP.Entry KEY_VALUE_GENERIC_TYPE o) { throw new UnsupportedOperationException(); }
 		@Override
@@ -749,15 +772,17 @@ public class MAPS
 		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator() { return ObjectIterators.unmodifiable(set.iterator()); }
 		@Override
+		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> reverseIterator() { return ObjectIterators.unmodifiable(set.reverseIterator()); }
+		@Override
 		public ObjectBidirectionalIterator<MAP.Entry KEY_VALUE_GENERIC_TYPE> iterator(MAP.Entry KEY_VALUE_GENERIC_TYPE fromElement) { return ObjectIterators.unmodifiable(set.iterator(fromElement)); }
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE first() { return set.first(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getFirst() { return set.getFirst(); }
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirst() { throw new UnsupportedOperationException(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeFirst() { throw new UnsupportedOperationException(); }
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE last() { return set.last(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE getLast() { return set.getLast(); }
 		@Override
-		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLast() { throw new UnsupportedOperationException(); }
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE removeLast() { throw new UnsupportedOperationException(); }
 	}
 	
 #endif
@@ -938,6 +963,10 @@ public class MAPS
 		@Override
 		public VALUE_TYPE putAndMoveToLast(KEY_TYPE key, VALUE_TYPE value) { synchronized(mutex) { return map.putAndMoveToLast(key, value); } }
 		@Override
+		public VALUE_TYPE putFirst(KEY_TYPE key, VALUE_TYPE value) { synchronized(mutex) { return map.putFirst(key, value); } }
+		@Override
+		public VALUE_TYPE putLast(KEY_TYPE key, VALUE_TYPE value) { synchronized(mutex) { return map.putLast(key, value); } }
+		@Override
 		public boolean moveToFirst(KEY_TYPE key) { synchronized(mutex) { return map.moveToFirst(key); } }
 		@Override
 		public boolean moveToLast(KEY_TYPE key) { synchronized(mutex) { return map.moveToLast(key); } }
@@ -958,13 +987,25 @@ public class MAPS
 		@Override
 		public VALUE_TYPE LAST_ENTRY_VALUE() { synchronized(mutex) { return map.LAST_ENTRY_VALUE(); } }
 		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE firstEntry() { synchronized(mutex) { return map.firstEntry(); } }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE lastEntry() { synchronized(mutex) { return map.lastEntry(); } }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollFirstEntry() { synchronized(mutex) { return map.pollFirstEntry(); } }
+		@Override
+		public MAP.Entry KEY_VALUE_GENERIC_TYPE pollLastEntry() { synchronized(mutex) { return map.pollLastEntry(); } }
+		@Override
 		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE copy() { synchronized(mutex) { return map.copy(); } }
 		@Override
 		public ORDERED_SET KEY_GENERIC_TYPE keySet() {
 			if(keys == null) keys = SETS.synchronize(map.keySet(), mutex);
 			return (ORDERED_SET KEY_GENERIC_TYPE)keys;
 		}
-		
+		@Override
+		public VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE values() {
+			if(values == null) values = VALUE_COLLECTIONS.synchronize(map.values(), mutex);
+			return (VALUE_ORDERED_COLLECTION VALUE_GENERIC_TYPE)values;
+		}
 		@Override
 		public ObjectOrderedSet<MAP.Entry KEY_VALUE_GENERIC_TYPE> ENTRY_SET() {
 			if(entrySet == null) entrySet = ObjectSets.synchronize(map.ENTRY_SET(), mutex);

src/builder/resources/speiger/assets/testers/templates/builder/OrderedSetTestSuiteBuilder.template

@@ -1,16 +1,29 @@
 package speiger.src.testers.PACKAGE.builder;
 
+import java.util.ArrayList;
+import java.util.Collection;
 import java.util.List;
 
 import com.google.common.collect.testing.AbstractTester;
+import com.google.common.collect.testing.FeatureSpecificTestSuiteBuilder;
 import com.google.common.collect.testing.Helpers;
+import com.google.common.collect.testing.OneSizeTestContainerGenerator;
+import com.google.common.collect.testing.SampleElements;
 import com.google.common.collect.testing.features.CollectionFeature;
+import com.google.common.collect.testing.features.Feature;
 
 import junit.framework.TestSuite;
+import speiger.src.collections.PACKAGE.collections.ITERABLE;
+import speiger.src.collections.PACKAGE.lists.ARRAY_LIST;
+import speiger.src.collections.PACKAGE.lists.LIST;
+import speiger.src.collections.PACKAGE.sets.ORDERED_SET;
+import speiger.src.collections.PACKAGE.utils.LISTS;
 import speiger.src.testers.PACKAGE.generators.TEST_ORDERED_SET_GENERATOR;
 import speiger.src.testers.PACKAGE.tests.set.FILE_KEY_TYPEOrderedSetMoveTester;
 import speiger.src.testers.PACKAGE.tests.set.FILE_KEY_TYPEOrderedSetIterationTester;
 import speiger.src.testers.PACKAGE.tests.set.FILE_KEY_TYPEOrderedSetNavigationTester;
+import speiger.src.testers.PACKAGE.utils.SAMPLE_ELEMENTS;
+import speiger.src.testers.utils.SpecialFeature;
 
 @SuppressWarnings("javadoc")
 public class ORDERED_SET_TEST_BUILDER KEY_GENERIC_TYPE extends SET_TEST_BUILDER KEY_GENERIC_TYPE {
@@ -35,4 +48,68 @@ public class ORDERED_SET_TEST_BUILDER KEY_GENERIC_TYPE extends SET_TEST_BUILDER
 #endignore
 		return super.createTestSuite();
 	}
+	
+	@Override
+	protected List<TestSuite> createDerivedSuites(
+			FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Collection<CLASS_TYPE>, CLASS_TYPE>> parentBuilder) {
+		List<TestSuite> derivedSuites = super.createDerivedSuites(parentBuilder);
+
+		if (!parentBuilder.getFeatures().contains(SpecialFeature.REVERSE)) {
+			derivedSuites.add(createReverseSuite(parentBuilder));
+		}
+
+		return derivedSuites;
+	}
+
+	private TestSuite createReverseSuite(FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Collection<CLASS_TYPE>, CLASS_TYPE>> parentBuilder) {
+		TEST_ORDERED_SET_GENERATOR KEY_GENERIC_TYPE delegate = (TEST_ORDERED_SET_GENERATOR KEY_GENERIC_TYPE) parentBuilder.getSubjectGenerator().getInnerGenerator();
+
+		List<Feature<?>> features = new ArrayList<>();
+		features.add(SpecialFeature.REVERSE);
+		features.addAll(parentBuilder.getFeatures());
+		features.remove(SpecialFeature.COPYING);
+		features.remove(SpecialFeature.CHILDREN_COPY);
+		
+		return ORDERED_SET_TEST_BUILDER.using(new TEST_ORDERED_SET_GENERATOR KEY_GENERIC_TYPE() {
+			@Override
+			public SampleElements<CLASS_TYPE> samples() {
+				return delegate.samples();
+			}
+			
+			@Override
+			public SAMPLE_ELEMENTS KEY_GENERIC_TYPE getSamples() {
+				return delegate.getSamples();
+			}
+
+			@Override
+			public ITERABLE KEY_GENERIC_TYPE order(LIST KEY_GENERIC_TYPE insertionOrder) {
+				return insertionOrder;
+			}
+
+			@Override
+			public Iterable<CLASS_TYPE> order(List<CLASS_TYPE> insertionOrder) {
+				return insertionOrder;
+			}
+			
+#if !TYPE_OBJECT
+			@Override
+			public ORDERED_SET KEY_GENERIC_TYPE create(KEY_TYPE... elements) {
+				LIST KEY_GENERIC_TYPE list = new ARRAY_LISTBRACES(elements);
+				LISTS.reverse(list);
+				return delegate.create(list.TO_ARRAY()).reversed();
+			}
+			
+#endif
+			@Override
+			public ORDERED_SET KEY_GENERIC_TYPE create(Object... elements) {
+				LIST KEY_GENERIC_TYPE list = new ARRAY_LISTBRACES();
+				for (Object e : elements) {
+					list.add(CLASS_TO_KEY(e));
+				}
+				LISTS.reverse(list);
+				return delegate.create(list.toArray()).reversed();
+			}
+		}).named(parentBuilder.getName() + " reversing").withFeatures(features)
+				.suppressing(parentBuilder.getSuppressedTests()).createTestSuite();
+	}
 }

src/builder/resources/speiger/assets/testers/templates/builder/maps/MapTestSuiteBuilder.template

@@ -238,21 +238,17 @@ public class MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MapTestSuiteBuilder
 	private static Set<Feature<?>> computeEntrySetFeatures(Set<Feature<?>> mapFeatures) {
 		Set<Feature<?>> entrySetFeatures = MapTestSuiteBuilder.computeCommonDerivedCollectionFeatures(mapFeatures);
 #ignore
-		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_ENTRY_QUERIES)) {
-			entrySetFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
-		}
-		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) {
-			entrySetFeatures.add(SpecialFeature.COPYING);
-		}
-		else {
-			entrySetFeatures.remove(SpecialFeature.COPYING);
-		}
-		if(mapFeatures.contains(SpecialFeature.MODIFIABLE)) {
-			entrySetFeatures.add(SpecialFeature.MODIFIABLE);
-		}
-		else {
-			entrySetFeatures.remove(SpecialFeature.MODIFIABLE);
-		}
+		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_ENTRY_QUERIES)) entrySetFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
+
+		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) entrySetFeatures.add(SpecialFeature.COPYING);
+		else entrySetFeatures.remove(SpecialFeature.COPYING);
+		
+		if(mapFeatures.contains(SpecialFeature.MODIFIABLE)) entrySetFeatures.add(SpecialFeature.MODIFIABLE);
+		else entrySetFeatures.remove(SpecialFeature.MODIFIABLE);
+		
+		if(mapFeatures.contains(SpecialFeature.REVERSE)) entrySetFeatures.add(SpecialFeature.REVERSE);
+		else entrySetFeatures.remove(SpecialFeature.REVERSE);
+		
 		entrySetFeatures.add(SpecialFeature.MAP_ENTRY);
 #endignore
 		return entrySetFeatures;
@@ -262,23 +258,17 @@ public class MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MapTestSuiteBuilder
 		Set<Feature<?>> keySetFeatures = MapTestSuiteBuilder.computeCommonDerivedCollectionFeatures(mapFeatures);
 #ignore
 		keySetFeatures.add(CollectionFeature.SUBSET_VIEW);
-		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_KEYS)) {
-			keySetFeatures.add(CollectionFeature.ALLOWS_NULL_VALUES);
-		} else if (mapFeatures.contains(MapFeature.ALLOWS_NULL_KEY_QUERIES)) {
-			keySetFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
-		}
-		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) {
-			keySetFeatures.add(SpecialFeature.COPYING);
-		}
-		else {
-			keySetFeatures.remove(SpecialFeature.COPYING);
-		}
-		if(mapFeatures.contains(SpecialFeature.MODIFIABLE)) {
-			keySetFeatures.add(SpecialFeature.MODIFIABLE);
-		}
-		else {
-			keySetFeatures.remove(SpecialFeature.MODIFIABLE);
-		}
+		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_KEYS)) keySetFeatures.add(CollectionFeature.ALLOWS_NULL_VALUES);
+		else if (mapFeatures.contains(MapFeature.ALLOWS_NULL_KEY_QUERIES)) keySetFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
+		
+		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) keySetFeatures.add(SpecialFeature.COPYING);
+		else keySetFeatures.remove(SpecialFeature.COPYING);
+		
+		if(mapFeatures.contains(SpecialFeature.MODIFIABLE)) keySetFeatures.add(SpecialFeature.MODIFIABLE);
+		else keySetFeatures.remove(SpecialFeature.MODIFIABLE);
+		
+		if(mapFeatures.contains(SpecialFeature.REVERSE)) keySetFeatures.add(SpecialFeature.REVERSE);
+		else keySetFeatures.remove(SpecialFeature.REVERSE);
 #endignore
 		return keySetFeatures;
 	}
@@ -287,18 +277,15 @@ public class MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MapTestSuiteBuilder
 	private static Set<Feature<?>> computeValuesCollectionFeatures(Set<Feature<?>> mapFeatures) {
 		Set<Feature<?>> valuesCollectionFeatures = MapTestSuiteBuilder.computeCommonDerivedCollectionFeatures(mapFeatures);
 #ignore
-		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_VALUE_QUERIES)) {
-			valuesCollectionFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
-		}
-		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_VALUES)) {
-			valuesCollectionFeatures.add(CollectionFeature.ALLOWS_NULL_VALUES);
-		}
-		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) {
-			valuesCollectionFeatures.add(SpecialFeature.COPYING);
-		}
-		else {
-			valuesCollectionFeatures.remove(SpecialFeature.COPYING);
-		}
+		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_VALUE_QUERIES)) valuesCollectionFeatures.add(CollectionFeature.ALLOWS_NULL_QUERIES);
+		
+		if (mapFeatures.contains(MapFeature.ALLOWS_NULL_VALUES)) valuesCollectionFeatures.add(CollectionFeature.ALLOWS_NULL_VALUES);
+		
+		if(mapFeatures.contains(SpecialFeature.CHILDREN_COPY)) valuesCollectionFeatures.add(SpecialFeature.COPYING); 
+		else valuesCollectionFeatures.remove(SpecialFeature.COPYING);
+		
+		if(mapFeatures.contains(SpecialFeature.REVERSE)) valuesCollectionFeatures.add(SpecialFeature.REVERSE);
+		else valuesCollectionFeatures.remove(SpecialFeature.REVERSE);
 #endignore
 		return valuesCollectionFeatures;
 	}

src/builder/resources/speiger/assets/testers/templates/builder/maps/OrderedMapTestSuiteBuilder.template

@@ -1,9 +1,14 @@
 package speiger.src.testers.PACKAGE.builder.maps;
 
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Map;
 
 import com.google.common.collect.testing.AbstractTester;
+import com.google.common.collect.testing.FeatureSpecificTestSuiteBuilder;
+import com.google.common.collect.testing.OneSizeTestContainerGenerator;
 import com.google.common.collect.testing.features.CollectionFeature;
+import com.google.common.collect.testing.features.Feature;
 
 import junit.framework.TestSuite;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
@@ -12,14 +17,17 @@ import speiger.src.testers.PACKAGE.builder.SET_TEST_BUILDER;
 import speiger.src.testers.PACKAGE.generators.TEST_ORDERED_SET_GENERATOR;
 import speiger.src.testers.PACKAGE.generators.TEST_SET_GENERATOR;
 import speiger.src.testers.PACKAGE.generators.maps.TEST_ORDERED_MAP_GENERATOR;
+import speiger.src.testers.PACKAGE.impl.maps.DERIVED_MAP_GENERATORS;
 import speiger.src.testers.PACKAGE.tests.maps.FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapMoveTester;
 import speiger.src.testers.PACKAGE.tests.maps.FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapNavigationTester;
+import speiger.src.testers.PACKAGE.tests.maps.FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapPutTester;
 #if !TYPE_OBJECT
 import speiger.src.testers.objects.builder.ObjectSetTestSuiteBuilder;
 import speiger.src.testers.objects.generators.TestObjectSetGenerator;
 import speiger.src.testers.objects.builder.ObjectOrderedSetTestSuiteBuilder;
 import speiger.src.testers.objects.generators.TestObjectOrderedSetGenerator;
 #endif
+import speiger.src.testers.utils.SpecialFeature;
 
 @SuppressWarnings("javadoc")
 public class ORDERED_MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE
@@ -34,6 +42,7 @@ public class ORDERED_MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MAP_TEST_BU
 		List<Class<? extends AbstractTester>> testers = super.getTesters();
 		testers.add(FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapMoveTester.class);
 		testers.add(FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapNavigationTester.class);
+		testers.add(FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapPutTester.class);
 		return testers;
 	}
 	
@@ -45,6 +54,15 @@ public class ORDERED_MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MAP_TEST_BU
 		return super.createTestSuite();
 	}
 	
+	@Override
+	protected List<TestSuite> createDerivedSuites(FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Map<CLASS_TYPE, CLASS_VALUE_TYPE>, Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE>>> parentBuilder) {
+		List<TestSuite> derivedSuites = super.createDerivedSuites(parentBuilder);
+		if (!parentBuilder.getFeatures().contains(SpecialFeature.REVERSE)) {
+			derivedSuites.add(createReverseSuite(parentBuilder));
+		}
+		return derivedSuites;
+	}
+	
 	protected ObjectSetTestSuiteBuilder<MAP.Entry KEY_VALUE_GENERIC_TYPE> createDerivedEntrySetSuite(TestObjectSetGenerator<MAP.Entry KEY_VALUE_GENERIC_TYPE> entrySetGenerator) {
 		return ObjectOrderedSetTestSuiteBuilder.using((TestObjectOrderedSetGenerator<MAP.Entry KEY_VALUE_GENERIC_TYPE>)entrySetGenerator);
 	}
@@ -52,4 +70,17 @@ public class ORDERED_MAP_TEST_BUILDER KEY_VALUE_GENERIC_TYPE extends MAP_TEST_BU
 	protected SET_TEST_BUILDER KEY_GENERIC_TYPE createDerivedKeySetSuite(TEST_SET_GENERATOR KEY_GENERIC_TYPE generator) {
 		return ORDERED_SET_TEST_BUILDER.using((TEST_ORDERED_SET_GENERATOR KEY_GENERIC_TYPE)generator);
 	}
+	
+	private TestSuite createReverseSuite(FeatureSpecificTestSuiteBuilder<?, ? extends OneSizeTestContainerGenerator<Map<CLASS_TYPE, CLASS_VALUE_TYPE>, Map.Entry<CLASS_TYPE, CLASS_VALUE_TYPE>>> parentBuilder) {
+		TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE delegate = (TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE) parentBuilder.getSubjectGenerator().getInnerGenerator();
+
+		List<Feature<?>> features = new ArrayList<>();
+		features.add(SpecialFeature.REVERSE);
+		features.addAll(parentBuilder.getFeatures());
+		features.remove(SpecialFeature.COPYING);
+		features.remove(SpecialFeature.CHILDREN_COPY);
+		return ORDERED_MAP_TEST_BUILDER.using(new DERIVED_MAP_GENERATORS.ReverseTestOrderedMapGenerator(delegate))
+				.named(parentBuilder.getName() + " reversed").withFeatures(features)
+				.suppressing(parentBuilder.getSuppressedTests()).createTestSuite();
+	}
 }

src/builder/resources/speiger/assets/testers/templates/impl/maps/DerivedMapGenerators.template

@@ -20,6 +20,7 @@ import speiger.src.collections.PACKAGE.maps.abstracts.ABSTRACT_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.MAP.Entry;
 import speiger.src.collections.PACKAGE.maps.interfaces.NAVIGABLE_MAP;
+import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
 import speiger.src.collections.PACKAGE.maps.interfaces.SORTED_MAP;
 #if !TYPE_OBJECT
 import speiger.src.collections.PACKAGE.sets.SET;
@@ -206,6 +207,22 @@ public class DERIVED_MAP_GENERATORS {
 		}
 	}
 	
+	public static class ReverseTestOrderedMapGenerator KEY_VALUE_GENERIC_TYPE extends MapGenerator KEY_VALUE_GENERIC_TYPE implements TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE {
+		TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE parent;
+		
+		public ReverseTestOrderedMapGenerator(TEST_ORDERED_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE parent) {
+			super(parent);
+			this.parent = parent;
+		}
+		
+		@Override
+		public ORDERED_MAP KEY_VALUE_GENERIC_TYPE create(Entry KEY_VALUE_GENERIC_TYPE... elements) {
+			ObjectList<Entry KEY_VALUE_GENERIC_TYPE> entries = new ObjectArrayList<Entry KEY_VALUE_GENERIC_TYPE>(elements);
+			ObjectLists.reverse(entries);
+			return ((ORDERED_MAP KEY_VALUE_GENERIC_TYPE)parent.create(entries.toArray(Entry[]::new))).reversed();
+		}
+	}
+	
 	public static class MapGenerator KEY_VALUE_GENERIC_TYPE implements TEST_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE
 	{
 		TEST_MAP_GENERATOR KEY_VALUE_GENERIC_TYPE parent;

src/builder/resources/speiger/assets/testers/templates/tests/collection/CollectionForEachTester.template

@@ -26,6 +26,15 @@ public class FILE_KEY_TYPECollectionForEachTester KEY_GENERIC_TYPE extends ABSTR
 		HELPERS.assertContentsAnyOrder(elements, createSamplesArray());
 	}
 
+#ignore
+	@CollectionFeature.Require(absent = KNOWN_ORDER)
+	public void testIndexedForEachUnknownOrder() {
+#endignore
+		LIST KEY_GENERIC_TYPE elements = new ARRAY_LISTBRACES();
+		collection.forEachIndexed((K, V) -> elements.add(V));
+		HELPERS.assertContentsAnyOrder(elements, createSamplesArray());
+	}
+	
 #ignore
 @CollectionFeature.Require(absent = KNOWN_ORDER)
 	public void testForEachExtraUnknownOrder() {
@@ -44,6 +53,15 @@ public class FILE_KEY_TYPECollectionForEachTester KEY_GENERIC_TYPE extends ABSTR
 		assertEquals("Different ordered iteration", HELPERS.copyToList(getOrderedElements()), elements);
 	}
 
+#ignore
+	@CollectionFeature.Require(KNOWN_ORDER)
+	public void testIndexedForEachKnownOrder() {
+#endignore
+		LIST KEY_GENERIC_TYPE elements = new ARRAY_LISTBRACES();
+		collection.forEachIndexed((K, V) -> elements.add(V));
+		assertEquals("Different ordered iteration", HELPERS.copyToList(getOrderedElements()), elements);
+	}
+	
 #ignore
 	@CollectionFeature.Require(KNOWN_ORDER)
 	public void testForEachExtraKnownOrder() {

src/builder/resources/speiger/assets/testers/templates/tests/iterable/IterableFindFirstTester.template

@@ -4,6 +4,12 @@ package speiger.src.testers.PACKAGE.tests.iterable;
 import java.util.Objects;
 
 #endif
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#else
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
+#endif
+
 import org.junit.Ignore;
 
 import com.google.common.collect.testing.features.CollectionSize;
@@ -27,17 +33,17 @@ public class FILE_KEY_TYPEIterableFindFirstTester KEY_GENERIC_TYPE extends ABSTR
 	@CollectionSize.Require(absent = CollectionSize.ZERO)
 #endignore
 	public void testIterableFindFirst_FindFirstElements() {
-		assertEquals("First Element should be found", e0(), container.findFirst(T -> KEY_EQUALS(T, e0())));
+		assertEquals("First Element should be found", e0(), container.findFirst(T -> KEY_EQUALS(T, e0())).SUPPLY_GET());
 	}
 	
 	public void testIterableFindFirst_FindNothing() {
-		assertEquals("No element should be found", EMPTY_KEY_VALUE, container.findFirst(T -> KEY_EQUALS(T, e4())));
+		assertEquals("No element should be found", OPTIONAL.empty(), container.findFirst(T -> KEY_EQUALS(T, e4())));
 	}
 	
 #ignore
 	@CollectionSize.Require(CollectionSize.SEVERAL)
 #endignore
 	public void testIterableFindFirst_FindLastElement() {
-		assertEquals("Last Element should be found", e2(), container.findFirst(T -> KEY_EQUALS(T, e2())));
+		assertEquals("Last Element should be found", e2(), container.findFirst(T -> KEY_EQUALS(T, e2())).SUPPLY_GET());
 	}
 }

src/builder/resources/speiger/assets/testers/templates/tests/iterable/IterableReduceTester.template

@@ -3,9 +3,16 @@ package speiger.src.testers.PACKAGE.tests.iterable;
 #if TYPE_OBJECT
 import java.util.Objects;
 
+#endif
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#else
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
 #endif
 import org.junit.Ignore;
 
+import com.google.common.collect.testing.features.CollectionSize;
+
 import speiger.src.testers.PACKAGE.tests.base.ABSTRACT_COLLECTION_TESTER;
 
 @Ignore
@@ -29,7 +36,7 @@ public class FILE_KEY_TYPEIterableReduceTester KEY_GENERIC_TYPE extends ABSTRACT
 	}
 	
 	public void testIterableReduce() {
-		assertEquals("The sum of the collection should match", getSum(), collection.reduce(this::sum));
+		assertEquals("The sum of the collection should match", size == CollectionSize.ZERO ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(getSum()), collection.reduce(this::sum));
 	}
 	
 	public void testIterableExtraReduce() {

src/builder/resources/speiger/assets/testers/templates/tests/maps/MapContainsTester.template

@@ -27,6 +27,7 @@ public class FILE_KEY_TYPE2FILE_VALUE_TYPEMapContainsTester KEY_VALUE_GENERIC_TY
 
 #ignore
 	@CollectionSize.Require(absent = ZERO)
+	@SuppressWarnings("unlikely-arg-type")
 #endignore
 	public void testContainsObject_yes() {
 		assertTrue("contains(present) should return true", getMap().ENTRY_SET().contains(new AbstractMap.SimpleEntry<>(e0())));
@@ -36,6 +37,7 @@ public class FILE_KEY_TYPE2FILE_VALUE_TYPEMapContainsTester KEY_VALUE_GENERIC_TY
 		assertFalse("contains(notPresent) should return false", getMap().ENTRY_SET().contains(e3()));
 	}
 	
+	@SuppressWarnings("unlikely-arg-type")
 	public void testContainsObject_no() {
 		assertFalse("contains(notPresent) should return false", getMap().ENTRY_SET().contains(new AbstractMap.SimpleEntry<>(e3())));
 	}

src/builder/resources/speiger/assets/testers/templates/tests/maps/MapRemoveEntryTester.template

@@ -136,6 +136,7 @@ public class FILE_KEY_TYPE2FILE_VALUE_TYPEMapRemoveEntryTester KEY_VALUE_GENERIC
 #ignore
 	@CollectionSize.Require(ONE)
 	@MapFeature.Require(SUPPORTS_REMOVE)
+	@SuppressWarnings("unlikely-arg-type")
 #endignore
 	public void testRemove_supportedObjectEntryPresent() {
 		assertTrue(getMap().ENTRY_SET().remove(new AbstractMap.SimpleEntry<>(e0())));
@@ -154,6 +155,7 @@ public class FILE_KEY_TYPE2FILE_VALUE_TYPEMapRemoveEntryTester KEY_VALUE_GENERIC
 #ignore
 	@CollectionSize.Require(ONE)
 	@MapFeature.Require(SUPPORTS_REMOVE)
+	@SuppressWarnings("unlikely-arg-type")
 #endignore
 	public void testRemove_supportedObjectEntryMissing() {
 		assertFalse(getMap().ENTRY_SET().remove(new AbstractMap.SimpleEntry<>(e3())));

src/builder/resources/speiger/assets/testers/templates/tests/maps/OrderedMapPutTester.template

@@ -0,0 +1,122 @@
+package speiger.src.testers.PACKAGE.tests.maps;
+
+#ignore
+import static com.google.common.collect.testing.features.CollectionSize.ZERO;
+import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_PUT;
+import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_REMOVE;
+import static org.junit.Assert.assertNotEquals;
+#endignore
+
+import com.google.common.collect.testing.features.CollectionSize;
+import com.google.common.collect.testing.features.MapFeature;
+
+import speiger.src.collections.PACKAGE.maps.interfaces.MAP;
+import speiger.src.collections.PACKAGE.maps.interfaces.ORDERED_MAP;
+import speiger.src.collections.objects.lists.ObjectList;
+import speiger.src.testers.PACKAGE.tests.base.maps.ABSTRACT_MAP_TESTER;
+import speiger.src.testers.objects.utils.ObjectHelpers;
+
+@SuppressWarnings("javadoc")
+public class FILE_KEY_TYPE2FILE_VALUE_TYPEOrderedMapPutTester KEY_VALUE_GENERIC_TYPE extends ABSTRACT_MAP_TESTER KEY_VALUE_GENERIC_TYPE
+{
+	private ORDERED_MAP KEY_VALUE_GENERIC_TYPE orderedMap;
+	private ObjectList<MAP.Entry KEY_VALUE_GENERIC_TYPE> values;
+	private KEY_TYPE a;
+	private VALUE_TYPE aValue;
+	private VALUE_TYPE cValue;
+	
+	@Override
+	public void setUp() throws Exception {
+		super.setUp();
+		orderedMap = (ORDERED_MAP KEY_VALUE_GENERIC_TYPE)getMap();
+		values = ObjectHelpers.copyToList(getSampleElements(getSubjectGenerator().getCollectionSize().getNumElements()));
+		if (values.size() >= 1) {
+			a = values.get(0).ENTRY_KEY();
+			aValue = values.get(0).ENTRY_VALUE();
+			if (values.size() >= 3) {
+				cValue = values.get(2).ENTRY_VALUE();
+			}
+		}
+	}
+	
+#ignore
+	@MapFeature.Require(SUPPORTS_PUT)
+	@CollectionSize.Require(absent = ZERO)
+#endignore
+	public void testPutFirst() {
+		assertEquals(aValue, orderedMap.putFirst(a, cValue));
+		assertNotEquals(cValue, orderedMap.FIRST_ENTRY_VALUE());
+		assertEquals(orderedMap.getDefaultReturnValue(), orderedMap.putFirst(k4(), v4()));
+		assertNotEquals(v4(), orderedMap.FIRST_ENTRY_VALUE());
+		assertEquals(e4(), orderedMap.firstEntry());
+	}
+	
+
+#ignore
+	@MapFeature.Require(SUPPORTS_PUT)
+	@CollectionSize.Require(absent = ZERO)
+#endignore
+	public void testPutLast() {
+		assertEquals(aValue, orderedMap.putLast(a, cValue));
+		assertNotEquals(cValue, orderedMap.LAST_ENTRY_VALUE());
+		assertEquals(orderedMap.getDefaultReturnValue(), orderedMap.putLast(k4(), v4()));
+		assertNotEquals(v4(), orderedMap.LAST_ENTRY_VALUE());
+		assertEquals(e4(), orderedMap.lastEntry());
+	}
+	
+#ignore
+	@MapFeature.Require(SUPPORTS_REMOVE)
+	@CollectionSize.Require(CollectionSize.ONE)
+#endignore
+	public void testPollFirst() {
+		assertFalse(orderedMap.isEmpty());
+		assertEquals(e0(), orderedMap.pollFirstEntry());
+		assertTrue(orderedMap.isEmpty());
+	}
+	
+#ignore
+	@MapFeature.Require(SUPPORTS_REMOVE)
+	@CollectionSize.Require(CollectionSize.ONE)
+#endignore
+	public void testPollLast() {
+		assertFalse(orderedMap.isEmpty());
+		assertEquals(e0(), orderedMap.pollLastEntry());
+		assertTrue(orderedMap.isEmpty());
+	}
+	
+#ignore
+	@MapFeature.Require(absent = SUPPORTS_PUT)
+#endignore
+	public void testUnsupportedPutFirst() {
+		try { orderedMap.putFirst(a, aValue); }
+		catch (UnsupportedOperationException tolerated) {}
+		expectUnchanged();
+	}
+	
+#ignore
+	@MapFeature.Require(absent = SUPPORTS_PUT)
+#endignore
+	public void testUnsupportedPutLast() {
+		try { orderedMap.putLast(a, aValue); }
+		catch (UnsupportedOperationException tolerated) {}
+		expectUnchanged();
+	}
+	
+#ignore
+	@MapFeature.Require(absent = SUPPORTS_REMOVE)
+#endignore
+	public void testUnsupportedPollFirst() {
+		try { orderedMap.pollFirstEntry(); }
+		catch (UnsupportedOperationException tolerated) {}
+		expectUnchanged();
+	}
+	
+#ignore
+	@MapFeature.Require(absent = SUPPORTS_REMOVE)
+#endignore
+	public void testUnsupportedPollLast() {
+		try { orderedMap.pollFirstEntry(); }
+		catch (UnsupportedOperationException tolerated) {}
+		expectUnchanged();
+	}
+}

src/builder/resources/speiger/assets/testers/templates/tests/queue/iterators/QueueFindFirstTester.template

@@ -2,6 +2,11 @@ package speiger.src.testers.PACKAGE.tests.queue.iterators;
 
 #if TYPE_OBJECT
 import java.util.Objects;
+#endif
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#else
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
 
 #endif
 import org.junit.Ignore;
@@ -27,17 +32,17 @@ public class FILE_KEY_TYPEQueueFindFirstTester KEY_GENERIC_TYPE extends ABSTRACT
 	@CollectionSize.Require(absent = CollectionSize.ZERO)
 #endignore
 	public void testQueueFindFirst_FindFirstElements() {
-		assertEquals("First Element should be found", e0(), queue.findFirst(T -> KEY_EQUALS(T, e0())));
+		assertEquals("First Element should be found", e0(), queue.findFirst(T -> KEY_EQUALS(T, e0())).SUPPLY_GET());
 	}
 	
 	public void testQueueFindFirst_FindNothing() {
-		assertEquals("No element should be found", EMPTY_KEY_VALUE, queue.findFirst(T -> KEY_EQUALS(T, e4())));
+		assertEquals("No element should be found", OPTIONAL.empty(), queue.findFirst(T -> KEY_EQUALS(T, e4())));
 	}
 	
 #ignore
 	@CollectionSize.Require(CollectionSize.SEVERAL)
 #endignore
 	public void testQueueFindFirst_FindLastElement() {
-		assertEquals("Last Element should be found", e2(), queue.findFirst(T -> KEY_EQUALS(T, e2())));
+		assertEquals("Last Element should be found", e2(), queue.findFirst(T -> KEY_EQUALS(T, e2())).SUPPLY_GET());
 	}
 }

src/builder/resources/speiger/assets/testers/templates/tests/queue/iterators/QueueReduceTester.template

@@ -3,10 +3,16 @@ package speiger.src.testers.PACKAGE.tests.queue.iterators;
 #if TYPE_OBJECT
 import java.util.Objects;
 
+#endif
+#if JDK_TYPE
+import java.util.OPTIONAL;
+#else
+import speiger.src.collections.PACKAGE.functions.OPTIONAL;
 #endif
 import org.junit.Ignore;
 
 import speiger.src.testers.PACKAGE.tests.base.ABSTRACT_QUEUE_TESTER;
+import com.google.common.collect.testing.features.CollectionSize;
 
 @Ignore
 @SuppressWarnings("javadoc")
@@ -29,7 +35,7 @@ public class FILE_KEY_TYPEQueueReduceTester KEY_GENERIC_TYPE extends ABSTRACT_QU
 	}
 	
 	public void testQueueReduce() {
-		assertEquals("The sum of the queue should match", getSum(), queue.reduce(this::sum));
+		assertEquals("The sum of the queue should match", size == CollectionSize.ZERO ? OPTIONAL.empty() : OPTIONAL.GET_OPTIONAL(getSum()), queue.reduce(this::sum));
 	}
 	
 	public void testQueueExtraReduce() {

src/builder/resources/speiger/assets/testers/templates/tests/set/OrderedSetMoveTester.template

@@ -45,10 +45,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testaddMoveToFirstMissing()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertEquals(true, orderedSet.addAndMoveToFirst(e4()));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(e4(), orderedSet.FIRST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(e4(), orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -57,10 +57,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testaddMoveToFirstPreset()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertEquals(false, orderedSet.addAndMoveToFirst(c));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(c, orderedSet.FIRST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(c, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -69,10 +69,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testaddMoveToLastMissing()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertEquals(true, orderedSet.addAndMoveToLast(e4()));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(e4(), orderedSet.LAST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(e4(), orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -81,10 +81,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testaddMoveToLastPreset()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertEquals(false, orderedSet.addAndMoveToLast(a));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(a, orderedSet.LAST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -93,9 +93,9 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveToFirstMissing()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertEquals(false, orderedSet.moveToFirst(e4()));
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -104,10 +104,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveToFirstPreset()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertEquals(true, orderedSet.moveToFirst(c));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(c, orderedSet.FIRST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(c, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -116,9 +116,9 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveToLastMissing()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertEquals(false, orderedSet.moveToLast(e4()));
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -127,10 +127,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveToLastPreset()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertEquals(true, orderedSet.moveToLast(a));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(a, orderedSet.LAST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -139,10 +139,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveCenterToLast()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertTrue(orderedSet.moveToLast(e1()));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(e1(), orderedSet.LAST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(e1(), orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -151,10 +151,10 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveCenterToFirst()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertTrue(orderedSet.moveToFirst(e1()));
-		assertNotEquals(c, orderedSet.FIRST_KEY());
-		assertEquals(e1(), orderedSet.FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_FIRST_KEY());
+		assertEquals(e1(), orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -163,13 +163,13 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveForthAndBack()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertTrue(orderedSet.moveToLast(e0()));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(a, orderedSet.LAST_KEY());
-		assertNotEquals(a, orderedSet.FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
 		assertTrue(orderedSet.moveToFirst(e0()));
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -178,13 +178,13 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testMoveBackAndForth()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertTrue(orderedSet.moveToFirst(e2()));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(c, orderedSet.FIRST_KEY());
-		assertNotEquals(c, orderedSet.LAST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(c, orderedSet.GET_FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
 		assertTrue(orderedSet.moveToLast(e2()));
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore
@@ -193,13 +193,13 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testAddForthAndBack()
 	{
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 		assertFalse(orderedSet.addAndMoveToLast(e0()));
-		assertNotEquals(c, orderedSet.LAST_KEY());
-		assertEquals(a, orderedSet.LAST_KEY());
-		assertNotEquals(a, orderedSet.FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
 		assertFalse(orderedSet.addAndMoveToFirst(e0()));
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}
 	
 #ignore
@@ -208,13 +208,13 @@ public class FILE_KEY_TYPEOrderedSetMoveTester KEY_GENERIC_TYPE extends ABSTRACT
 #endignore
 	public void testAddBackAndForth()
 	{
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 		assertFalse(orderedSet.addAndMoveToFirst(e2()));
-		assertNotEquals(a, orderedSet.FIRST_KEY());
-		assertEquals(c, orderedSet.FIRST_KEY());
-		assertNotEquals(c, orderedSet.LAST_KEY());
+		assertNotEquals(a, orderedSet.GET_FIRST_KEY());
+		assertEquals(c, orderedSet.GET_FIRST_KEY());
+		assertNotEquals(c, orderedSet.GET_LAST_KEY());
 		assertFalse(orderedSet.addAndMoveToLast(e2()));
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 	}
 	
 #ignore

src/builder/resources/speiger/assets/testers/templates/tests/set/OrderedSetNavigationTester.template

@@ -68,7 +68,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 		int polled = 0;
 		int expectedPolls = orderedSet.size();
 		while(polled < expectedPolls) {
-			orderedSet.POLL_FIRST_KEY();
+			orderedSet.REMOVE_FIRST_KEY();
 			polled++;
 		}
 		assertTrue("Map should be empty", orderedSet.isEmpty());
@@ -82,7 +82,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 		int polled = 0;
 		int expectedPolls = orderedSet.size();
 		while(polled < expectedPolls) {
-			orderedSet.POLL_LAST_KEY();
+			orderedSet.REMOVE_LAST_KEY();
 			polled++;
 		}
 		assertTrue("Map should be empty", orderedSet.isEmpty());
@@ -94,8 +94,8 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testEmptySetPollFirst() {
 		try {
-			orderedSet.POLL_FIRST_KEY();
-			fail("OrderedSet.POLL_FIRST_KEY should throw NoSuchElementException");
+			orderedSet.REMOVE_FIRST_KEY();
+			fail("OrderedSet.REMOVE_FIRST_KEY should throw NoSuchElementException");
 		} catch (NoSuchElementException e) {
 		}
 		expectUnchanged();
@@ -107,8 +107,8 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testEmptySetPollLast() {
 		try {
-			orderedSet.POLL_LAST_KEY();
-			fail("OrderedSet.POLL_LAST_KEY should throw NoSuchElementException");
+			orderedSet.REMOVE_LAST_KEY();
+			fail("OrderedSet.REMOVE_LAST_KEY should throw NoSuchElementException");
 		} catch (NoSuchElementException e) {
 		}
 		expectUnchanged();
@@ -119,8 +119,8 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testUnsupportedSetPollFirst() {
 		try {
-			orderedSet.POLL_FIRST_KEY();
-			fail("OrderedSet.POLL_FIRST_KEY should throw UnsupportedOperationException");
+			orderedSet.REMOVE_FIRST_KEY();
+			fail("OrderedSet.REMOVE_FIRST_KEY should throw UnsupportedOperationException");
 		} catch (UnsupportedOperationException e) {
 		}
 		expectUnchanged();
@@ -131,8 +131,8 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testUnsupportedSetPollLast() {
 		try {
-			orderedSet.POLL_LAST_KEY();
-			fail("OrderedSet.POLL_LAST_KEY should throw UnsupportedOperationException");
+			orderedSet.REMOVE_LAST_KEY();
+			fail("OrderedSet.REMOVE_LAST_KEY should throw UnsupportedOperationException");
 		} catch (UnsupportedOperationException e) {
 		}
 		expectUnchanged();
@@ -143,7 +143,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(ONE)
 #endignore
 	public void testSingletonSetPollFirst() {
-		assertEquals(a, orderedSet.POLL_FIRST_KEY());
+		assertEquals(a, orderedSet.REMOVE_FIRST_KEY());
 		assertTrue(orderedSet.isEmpty());
 	}
 	
@@ -152,7 +152,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(ONE)
 #endignore
 	public void testSingletonSetPollLast() {
-		assertEquals(a, orderedSet.POLL_LAST_KEY());
+		assertEquals(a, orderedSet.REMOVE_LAST_KEY());
 		assertTrue(orderedSet.isEmpty());
 	}
 	
@@ -161,7 +161,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(SEVERAL)
 #endignore
 	public void testPollFirst() {
-		assertEquals(a, orderedSet.POLL_FIRST_KEY());
+		assertEquals(a, orderedSet.REMOVE_FIRST_KEY());
 		assertEquals(values.subList(1, values.size()), HELPERS.copyToList(orderedSet));
 	}
 
@@ -170,7 +170,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(SEVERAL)
 #endignore
 	public void testPollLast() {
-		assertEquals(c, orderedSet.POLL_LAST_KEY());
+		assertEquals(c, orderedSet.REMOVE_LAST_KEY());
 		assertEquals(values.subList(0, values.size()-1), HELPERS.copyToList(orderedSet));
 	}
 	
@@ -179,7 +179,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testPollFirstUnsupported() {
 		try {
-			orderedSet.POLL_FIRST_KEY();
+			orderedSet.REMOVE_FIRST_KEY();
 			fail();
 		} catch (UnsupportedOperationException e) {
 		}
@@ -190,7 +190,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testPollLastUnsupported() {
 		try {
-			orderedSet.POLL_LAST_KEY();
+			orderedSet.REMOVE_LAST_KEY();
 			fail();
 		} catch (UnsupportedOperationException e) {
 		}
@@ -201,7 +201,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testEmptySetFirst() {
 		try {
-			orderedSet.FIRST_KEY();
+			orderedSet.GET_FIRST_KEY();
 			fail();
 		} catch (NoSuchElementException e) {
 		}
@@ -212,7 +212,7 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 #endignore
 	public void testEmptySetLast() {
 		try {
-			orderedSet.LAST_KEY();
+			orderedSet.GET_LAST_KEY();
 			fail();
 		} catch (NoSuchElementException e) {
 		}
@@ -222,27 +222,27 @@ public class FILE_KEY_TYPEOrderedSetNavigationTester KEY_GENERIC_TYPE extends AB
 	@CollectionSize.Require(ONE)
 #endignore
 	public void testSingletonSetFirst() {
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}
 
 #ignore
 	@CollectionSize.Require(ONE)
 #endignore
 	public void testSingletonSetLast() {
-		assertEquals(a, orderedSet.LAST_KEY());
+		assertEquals(a, orderedSet.GET_LAST_KEY());
 	}
 
 #ignore
 	@CollectionSize.Require(SEVERAL)
 #endignore
 	public void testFirst() {
-		assertEquals(a, orderedSet.FIRST_KEY());
+		assertEquals(a, orderedSet.GET_FIRST_KEY());
 	}
 
 #ignore
 	@CollectionSize.Require(SEVERAL)
 #endignore
 	public void testLast() {
-		assertEquals(c, orderedSet.LAST_KEY());
+		assertEquals(c, orderedSet.GET_LAST_KEY());
 	}
 }

src/main/java/speiger/src/collections/booleans/collections/AbstractBooleanCollection.java

@@ -0,0 +1,318 @@
+package speiger.src.collections.booleans.collections;
+
+import java.util.Collection;
+import java.util.function.Supplier;
+import java.util.Objects;
+import java.util.AbstractCollection;
+
+import speiger.src.collections.booleans.lists.BooleanListIterator;
+import speiger.src.collections.booleans.functions.BooleanConsumer;
+import speiger.src.collections.booleans.utils.BooleanIterators;
+import speiger.src.collections.booleans.utils.BooleanArrays;
+
+/**
+ * Abstract Type Specific Collection that reduces boxing/unboxing
+ */
+public abstract class AbstractBooleanCollection extends AbstractCollection<Boolean> implements BooleanCollection
+{
+	@Override
+	public abstract BooleanIterator iterator();
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	public boolean add(Boolean e) { return BooleanCollection.super.add(e); }
+
+	@Override
+	public boolean addAll(BooleanCollection c) {
+		boolean modified = false;
+		for(BooleanIterator iter = c.iterator();iter.hasNext();modified |= add(iter.nextBoolean()));
+		return modified;
+	}
+	
+	@Override
+	public BooleanCollection copy() { throw new UnsupportedOperationException(); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	public boolean contains(Object e) { return BooleanCollection.super.contains(e); }
+	
+	/**
+	 * A Type-Specific implementation of contains. This implementation iterates over the elements and returns true if the value match.
+	 * @param e the element that should be searched for.
+	 * @return true if the value was found.
+	 */
+	@Override
+	public boolean contains(boolean e) {
+		for(BooleanIterator iter = iterator();iter.hasNext();) { if(iter.nextBoolean() == e) return true; }
+		return false;
+	}
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	public boolean addAll(Collection<? extends Boolean> c)
+	{
+		return c instanceof BooleanCollection ? addAll((BooleanCollection)c) : super.addAll(c);
+	}
+	
+	/**
+	 * A Type-Specific implementation of containsAll. This implementation iterates over all elements and checks all elements are present in the other collection.
+	 * @param c the collection that should be checked if it contains all elements.
+	 * @return true if all elements were found in the collection
+	 * @throws java.lang.NullPointerException if the collection is null
+	 */
+	@Override
+	public boolean containsAll(BooleanCollection c) {
+		Objects.requireNonNull(c);
+		if(c.isEmpty()) return true;
+		for(BooleanIterator iter = c.iterator();iter.hasNext();)
+			if(!contains(iter.nextBoolean()))
+				return false;
+		return true;
+	}
+	
+	@Override
+	public boolean containsAll(Collection<?> c) {
+		Objects.requireNonNull(c);
+		return c instanceof BooleanCollection ? containsAll((BooleanCollection)c) : super.containsAll(c);
+	}
+	
+	/**
+	 * This implementation iterates over the elements of the collection and checks if they are stored in this collection
+	 * @param c the elements that should be checked for
+	 * @return true if any element is in this collection
+	 * @throws java.lang.NullPointerException if the collection is null
+	 */
+	@Override
+	@Deprecated
+	public boolean containsAny(Collection<?> c) {
+		Objects.requireNonNull(c);
+		if(c.isEmpty()) return false;
+		for(Object e : c) 
+			if(contains(e))
+				return true;
+		return false;
+	}
+	
+	/**
+	 * This implementation iterates over the elements of the collection and checks if they are stored in this collection.
+	 * @param c the elements that should be checked for
+	 * @return true if any element is in this collection
+ 	 * @throws java.lang.NullPointerException if the collection is null
+	 */
+	@Override
+	public boolean containsAny(BooleanCollection c) {
+		Objects.requireNonNull(c);
+		if(c.isEmpty()) return false;
+		for(BooleanIterator iter = c.iterator();iter.hasNext();) 
+			if(contains(iter.nextBoolean()))
+				return true;
+		return false;
+	}
+		
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	public boolean remove(Object e) { return BooleanCollection.super.remove(e); }
+	
+	/**
+	 * A Type-Specific implementation of remove. This implementation iterates over the elements until it finds the element that is searched for or it runs out of elements.
+	 * It stops after finding the first element
+	 * @param e the element that is searched for
+	 * @return true if the element was found and removed.
+	 */
+	@Override
+	public boolean remBoolean(boolean e) {
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			if(iter.nextBoolean() == e) {
+				iter.remove();
+				return true;
+			}
+		}
+		return false;
+	}
+	
+	/**
+	 * A Type-Specific implementation of removeAll. This Implementation iterates over all elements and removes them as they were found in the other collection.
+	 * @param c the elements that should be deleted
+	 * @return true if the collection was modified.
+	 * @throws java.lang.NullPointerException if the collection is null
+	 */
+	@Override
+	public boolean removeAll(BooleanCollection c) {
+		Objects.requireNonNull(c);
+		if(c.isEmpty()) return false;
+		boolean modified = false;
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			if(c.contains(iter.nextBoolean())) {
+				iter.remove();
+				modified = true;
+			}
+		}
+		return modified;
+	}
+
+	@Override
+	public boolean removeAll(BooleanCollection c, BooleanConsumer r) {
+		Objects.requireNonNull(c);
+		if(c.isEmpty()) return false;
+		Objects.requireNonNull(r);
+		boolean modified = false;
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			boolean e = iter.nextBoolean();
+			if(c.contains(e)) {
+				r.accept(e);
+				iter.remove();
+				modified = true;
+			}
+		}
+		return modified;
+	}
+	
+	/**
+	 * A Type-Specific implementation of retainAll. This Implementation iterates over all elements and removes them as they were not found in the other collection.
+	 * @param c the elements that should be kept
+	 * @return true if the collection was modified.
+	 * @throws java.lang.NullPointerException if the collection is null
+	 */
+	@Override
+	public boolean retainAll(BooleanCollection c) {
+		Objects.requireNonNull(c);
+		if(c.isEmpty()) {
+			boolean modified = !isEmpty();
+			clear();
+			return modified;
+		}
+		boolean modified = false;
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			if(!c.contains(iter.nextBoolean())) {
+				iter.remove();
+				modified = true;
+			}
+		}
+		return modified;
+	}
+	
+	@Override
+	public boolean retainAll(BooleanCollection c, BooleanConsumer r) {
+		Objects.requireNonNull(c);
+		Objects.requireNonNull(r);
+		if(c.isEmpty()) {
+			boolean modified = !isEmpty();
+			forEach(r);
+			clear();
+			return modified;
+		}
+		boolean modified = false;
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			boolean e = iter.nextBoolean();
+			if(!c.contains(e)) {
+				r.accept(e);
+				iter.remove();
+				modified = true;
+			}
+		}
+		return modified;
+	}
+	
+	/**
+	 * A Type-Specific implementation of toArray that links to {@link #toBooleanArray(boolean[])} with a newly created array.
+	 * @return an array containing all of the elements in this collection
+	 */
+	@Override
+	public boolean[] toBooleanArray() {
+		if(isEmpty()) return BooleanArrays.EMPTY_ARRAY;
+		return toBooleanArray(new boolean[size()]);
+	}
+	
+	/**
+	 * A Type-Specific implementation of toArray. This implementation iterates over all elements and unwraps them into primitive type.
+	 * @param a array that the elements should be injected to. If null or to small a new array with the right size is created
+	 * @return an array containing all of the elements in this collection
+	 */
+	@Override
+	public boolean[] toBooleanArray(boolean[] a) {
+		if(a == null || a.length < size()) a = new boolean[size()];
+		BooleanIterators.unwrap(a, iterator());
+		if (a.length > size()) a[size()] = false;
+		return a;
+	}
+
+	public static class ReverseBooleanOrderedCollection extends AbstractBooleanCollection implements BooleanOrderedCollection {
+		BooleanOrderedCollection collection;
+		Supplier<BooleanIterator> reverseIterator;
+		
+		public ReverseBooleanOrderedCollection(BooleanOrderedCollection collection, Supplier<BooleanIterator> reverseIterator) {
+			this.collection = collection;
+			this.reverseIterator = reverseIterator;
+		}
+		
+		@Override
+		public boolean add(boolean o) { return collection.add(o); }
+		@Override
+		public BooleanOrderedCollection reversed() { return collection; }
+		@Override
+		public void addFirst(boolean e) { collection.addLast(e); }
+		@Override
+		public void addLast(boolean e) { collection.addFirst(e); }
+		@Override
+		public boolean contains(boolean e) { return collection.contains(e); }
+		@Override
+		public boolean remBoolean(boolean e) { return collection.remBoolean(e); }
+		@Override
+		public void clear() { collection.clear(); }
+		@Override
+		public boolean getFirstBoolean() { return collection.getLastBoolean(); }
+		@Override
+		public boolean removeFirstBoolean() { return collection.removeLastBoolean(); }
+		@Override
+		public boolean getLastBoolean() { return collection.getFirstBoolean(); }
+		@Override
+		public boolean removeLastBoolean() { return collection.removeFirstBoolean(); }
+		@Override
+		public BooleanIterator iterator() { return reverseIterator.get(); }
+		@Override
+		public int size() { return collection.size(); }
+	}
+	
+	public static class ReverseBiIterator implements BooleanListIterator {
+		BooleanListIterator it;
+		
+		public ReverseBiIterator(BooleanListIterator it) {
+			this.it = it;
+		}
+		
+		@Override
+		public boolean nextBoolean() { return it.previousBoolean(); }
+		@Override
+		public boolean hasNext() { return it.hasPrevious(); }
+		@Override
+		public boolean hasPrevious() { return it.hasNext(); }
+		@Override
+		public boolean previousBoolean() { return it.nextBoolean(); }
+		@Override
+		public void remove() { it.remove(); }
+		@Override
+		public int nextIndex() { return it.previousIndex(); }
+		@Override
+		public int previousIndex() { return it.nextIndex(); }
+		@Override
+		public void set(boolean e) { it.set(e); }
+		@Override
+		public void add(boolean e) { it.add(e); }
+	}
+}

src/main/java/speiger/src/collections/booleans/collections/BooleanBidirectionalIterator.java

@@ -0,0 +1,52 @@
+package speiger.src.collections.booleans.collections;
+
+/**
+ * This is a basically a {@link java.util.ListIterator} without the index functions.
+ * Allowing to have a simple Bidirectional Iterator without having to keep track of the Iteration index.
+ */
+public interface BooleanBidirectionalIterator extends BooleanIterator
+{
+	/**
+	 * Returns true if the Iterator has a Previous element
+	 * @return true if the Iterator has a Previous element
+	 */
+	public boolean hasPrevious();
+	
+	/**
+	 * Returns the Previous element of the iterator.
+	 * @return the Previous element of the iterator.
+ 	 * @throws java.util.NoSuchElementException if the iteration has no more elements
+	 */
+	public boolean previousBoolean();
+	
+	/**
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 * @return the Previous element of the iterator.+
+	 */
+	@Deprecated
+	public default Boolean previous() {
+		return Boolean.valueOf(previousBoolean());
+	}
+	
+	/**
+	 * {@inheritDoc}
+	 */
+	@Override
+	default int skip(int amount)
+	{
+		return BooleanIterator.super.skip(amount);
+	}
+	
+	/**
+	 * Reverses the Given amount of elements if possible. A Optimization function to reverse elements faster if the implementation allows it.
+	 * @param amount the amount of elements that should be reversed
+	 * @return the amount of elements that were reversed
+	 */
+	public default int back(int amount) {
+		if(amount < 0) throw new IllegalStateException("Can't go forward");
+		int i = 0;
+		for(;i<amount && hasPrevious();previousBoolean(),i++);
+		return i;
+	}
+}

src/main/java/speiger/src/collections/booleans/collections/BooleanCollection.java

@@ -0,0 +1,231 @@
+package speiger.src.collections.booleans.collections;
+
+import java.util.Collection;
+import speiger.src.collections.booleans.functions.BooleanConsumer;
+import speiger.src.collections.booleans.utils.BooleanSplititerators;
+import speiger.src.collections.booleans.utils.BooleanCollections;
+import speiger.src.collections.utils.ISizeProvider;
+import speiger.src.collections.utils.SanityChecks;
+
+/**
+ * A Type-Specific {@link Collection} that reduces (un)boxing
+ */
+public interface BooleanCollection extends Collection<Boolean>, BooleanIterable, ISizeProvider
+{
+	/**
+	 * A Type-Specific add function to reduce (un)boxing
+	 * @param o the element that should be added
+	 * @return true if the element was added to the collection
+	 */
+	public boolean add(boolean o);
+	
+	/**
+	 * A Type-Specific addAll function to reduce (un)boxing
+	 * @param c the collection of elements that should be added
+	 * @return true if elements were added into the collection
+	 */
+	public boolean addAll(BooleanCollection c);
+	
+	/**
+	 * A Type-Specific Array based addAll method to reduce the amount of Wrapping
+	 * @param e the elements that should be added
+	 * @return if the collection was modified
+	 */
+	public default boolean addAll(boolean... e) { return addAll(e, 0, e.length); }
+	
+	/**
+	 * A Type-Specific Array based addAll method to reduce the amount of Wrapping
+	 * @param e the elements that should be added
+	 * @param length how many elements of the array should be added
+	 * @return if the collection was modified
+	 */
+	public default boolean addAll(boolean[] e, int length) { return addAll(e, 0, length); }
+	
+	/**
+	 * A Type-Specific Array based addAll method to reduce the amount of Wrapping
+	 * @param e the elements that should be added
+	 * @param offset where to start within the array
+	 * @param length how many elements of the array should be added
+	 * @return if the collection was modified
+	 */
+	public default boolean addAll(boolean[] e, int offset, int length) {
+		if(length <= 0) return false;
+		SanityChecks.checkArrayCapacity(e.length, offset, length);
+		boolean added = false;
+		for(int i = 0;i<length;i++) {
+			if(add(e[offset+i])) added = true;
+		}
+		return added;
+	}
+	
+	/**
+	 * A Type-Specific contains function to reduce (un)boxing
+	 * @param o the element that is checked for
+	 * @return true if the element is found in the collection
+	 */
+	public boolean contains(boolean o);
+	
+	/**
+ 	 * A Type-Specific containsAll function to reduce (un)boxing
+ 	 * @param c the collection of elements that should be tested for
+ 	 * @return true if all the element is found in the collection
+ 	 */
+	public boolean containsAll(BooleanCollection c);
+	
+	/**
+	 * A Type-Specific containsAny function to reduce (un)boxing
+ 	 * @param c the collection of elements that should be tested for
+	 * @return true if any element was found
+	 */
+	public boolean containsAny(BooleanCollection c);
+	
+	/**
+	 * Returns true if any element of the Collection is found in the provided collection.
+	 * A Small Optimization function to find out of any element is present when comparing collections and not all of them.
+ 	 * @param c the collection of elements that should be tested for
+	 * @return true if any element was found.
+	 */
+	@Deprecated
+	public boolean containsAny(Collection<?> c);
+	
+	/**
+	 * A Type-Specific remove function that reduces (un)boxing.
+	 * @param o the element that should be removed
+	 * @return true if the element was removed
+	 * @see Collection#remove(Object)
+	 */
+	public boolean remBoolean(boolean o);
+	
+	/**
+	 * A Type-Specific removeAll function that reduces (un)boxing.
+	 * @param c the collection of elements that should be removed
+	 * @return true if any element was removed
+	 * @see Collection#removeAll(Collection)
+	 */
+	public boolean removeAll(BooleanCollection c);
+	
+	/**
+	 * A Type-Specific removeAll function that reduces (un)boxing.
+	 * It also notifies the remover of which exact element is going to be removed.
+	 * @param c the collection of elements that should be removed
+	 * @param r elements that got removed
+	 * @return true if any element was removed
+	 * @see Collection#removeAll(Collection)
+	 */
+	public boolean removeAll(BooleanCollection c, BooleanConsumer r);
+	
+	/**
+ 	 * A Type-Specific retainAll function that reduces (un)boxing.
+	 * @param c the collection of elements that should be kept
+ 	 * @return true if any element was removed
+ 	 * @see Collection#retainAll(Collection)
+ 	 */
+	public boolean retainAll(BooleanCollection c);
+	
+	/**
+ 	 * A Type-Specific retainAll function that reduces (un)boxing.
+	 * It also notifies the remover of which exact element is going to be removed.
+	 * @param c the collection of elements that should be kept
+	 * @param r elements that got removed
+ 	 * @return true if any element was removed
+ 	 * @see Collection#retainAll(Collection)
+ 	 */
+	public boolean retainAll(BooleanCollection c, BooleanConsumer r);
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to collect all elements
+	 * @param collection that the elements should be inserted to
+	 * @param <E> the collection type
+	 * @return the input with the desired elements
+	 */
+	default <E extends BooleanCollection> E pour(E collection) {
+		collection.addAll(this);
+		return collection;
+	}
+	
+	/**
+	 * A Function that does a shallow clone of the Collection itself.
+	 * This function is more optimized then a copy constructor since the Collection does not have to be unsorted/resorted.
+	 * It can be compared to Cloneable but with less exception risk
+	 * @return a Shallow Copy of the collection
+	 * @note Wrappers and view collections will not support this feature
+	 */
+	public BooleanCollection copy();
+	
+	/**
+	 * A Type-Specific toArray function that delegates to {@link #toBooleanArray(boolean[])} with a newly created array.
+	 * @return an array containing all of the elements in this collection
+	 * @see Collection#toArray()
+	 */
+	public boolean[] toBooleanArray();
+	
+	/**
+	 * A Type-Specific toArray function that reduces (un)boxing.
+	 * @param a array that the elements should be injected to. If null or to small a new array with the right size is created
+	 * @return an array containing all of the elements in this collection
+	 * @see Collection#toArray(Object[])
+	 */
+	public boolean[] toBooleanArray(boolean[] a);
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	public default boolean add(Boolean o) { return add(o.booleanValue()); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	public default boolean contains(Object o) { return o != null && contains(((Boolean)o).booleanValue()); }
+	
+	/** {@inheritDoc}
+ 	 * <p>This default implementation delegates to the corresponding type-specific function.
+ 	 * @deprecated Please use the corresponding type-specific function instead. 
+ 	 */
+	@Override
+	@Deprecated
+	public default boolean remove(Object o) { return o != null && remBoolean(((Boolean)o).booleanValue()); }
+	
+	/**
+	 * Returns a Type-Specific Iterator to reduce (un)boxing
+	 * @return a iterator of the collection
+	 * @see Collection#iterator()
+	 */
+	@Override
+	public BooleanIterator iterator();
+	
+	/**
+	 * Creates a Wrapped Collection that is Synchronized
+	 * @return a new Collection that is synchronized
+	 * @see BooleanCollections#synchronize
+	 */
+	public default BooleanCollection synchronize() { return BooleanCollections.synchronize(this); }
+	
+	/**
+	 * Creates a Wrapped Collection that is Synchronized
+	 * @param mutex is the controller of the synchronization block
+	 * @return a new Collection Wrapper that is synchronized
+	 * @see BooleanCollections#synchronize
+	 */
+	public default BooleanCollection synchronize(Object mutex) { return BooleanCollections.synchronize(this, mutex); }
+	
+	/**
+	 * Creates a Wrapped Collection that is unmodifiable
+	 * @return a new Collection Wrapper that is unmodifiable
+	 * @see BooleanCollections#unmodifiable
+	 */
+	public default BooleanCollection unmodifiable() { return BooleanCollections.unmodifiable(this); }
+	
+
+	/**
+	 * A Type Specific Type Splititerator to reduce boxing/unboxing
+	 * @return type specific splititerator
+	 */
+	@Override
+	default BooleanSplititerator spliterator() { return BooleanSplititerators.createSplititerator(this, 0); }
+}

src/main/java/speiger/src/collections/booleans/collections/BooleanIterable.java

@@ -0,0 +1,334 @@
+package speiger.src.collections.booleans.collections;
+
+import java.util.Objects;
+import java.util.function.Consumer;
+
+
+import speiger.src.collections.booleans.functions.BooleanConsumer;
+import speiger.src.collections.booleans.functions.BooleanComparator;
+import speiger.src.collections.objects.collections.ObjectIterable;
+import speiger.src.collections.booleans.functions.OptionalBoolean;
+import speiger.src.collections.booleans.functions.function.BooleanFunction;
+import speiger.src.collections.ints.functions.consumer.IntBooleanConsumer;
+import speiger.src.collections.objects.functions.consumer.ObjectBooleanConsumer;
+import speiger.src.collections.booleans.functions.function.BooleanPredicate;
+import speiger.src.collections.booleans.functions.function.BooleanBooleanUnaryOperator;
+import speiger.src.collections.booleans.lists.BooleanList;
+import speiger.src.collections.booleans.lists.BooleanArrayList;
+import speiger.src.collections.booleans.utils.BooleanArrays;
+import speiger.src.collections.booleans.utils.BooleanAsyncBuilder;
+import speiger.src.collections.booleans.utils.BooleanSplititerators;
+import speiger.src.collections.booleans.utils.BooleanIterables;
+import speiger.src.collections.booleans.utils.BooleanIterators;
+import speiger.src.collections.utils.ISizeProvider;
+
+/**
+ * A Type-Specific {@link Iterable} that reduces (un)boxing
+ */
+public interface BooleanIterable extends Iterable<Boolean>
+{
+	/**
+	 * Returns an iterator over elements of type {@code T}.
+	 *
+	 * @return an Iterator.
+	 */
+	@Override
+	BooleanIterator iterator();
+	
+	/**
+	 * A Type Specific foreach function that reduces (un)boxing
+	 * 
+	 * @implSpec
+	 * <p>The default implementation behaves as if:
+	 * <pre>{@code
+	 *	iterator().forEachRemaining(action);
+	 * }</pre>
+	 *
+	 * @param action The action to be performed for each element
+	 * @throws NullPointerException if the specified action is null
+	 * @see Iterable#forEach(Consumer)
+	 */
+	default void forEach(BooleanConsumer action) {
+		Objects.requireNonNull(action);
+		iterator().forEachRemaining(action);
+	}
+	
+	/** {@inheritDoc}
+	* <p>This default implementation delegates to the corresponding type-specific function.
+	* @deprecated Please use the corresponding type-specific function instead. 
+	*/
+	@Deprecated
+	@Override
+	default void forEach(Consumer<? super Boolean> action) {
+		Objects.requireNonNull(action);
+		iterator().forEachRemaining(action);
+	}
+	
+	/**
+	 * A Indexed forEach implementation that allows you to keep track of how many elements were already iterated over.
+	 * @param action The action to be performed for each element
+	 * @throws java.lang.NullPointerException if the specified action is null
+	 */
+	public default void forEachIndexed(IntBooleanConsumer action) {
+		Objects.requireNonNull(action);
+		int index = 0;
+		for(BooleanIterator iter = iterator();iter.hasNext();action.accept(index++, iter.nextBoolean()));
+	}
+	
+	/**
+	 * Helper function to reduce Lambda usage and allow for more method references, since these are faster/cleaner.
+	 * @param input the object that should be included
+	 * @param action The action to be performed for each element
+	 * @param <E> the generic type of the Object
+	 * @throws java.lang.NullPointerException if the specified action is null
+	 */
+	default <E> void forEach(E input, ObjectBooleanConsumer<E> action) {
+		Objects.requireNonNull(action);
+		iterator().forEachRemaining(input, action);
+	}
+	
+	/**
+	 * A Type Specific Type Splititerator to reduce boxing/unboxing
+	 * @return type specific splititerator
+	 */
+	@Override
+	default BooleanSplititerator spliterator() { return BooleanSplititerators.createUnknownSplititerator(iterator(), 0); }
+	
+	/**
+	 * Creates a Async Builder for moving work of the thread.
+	 * It is not designed to split the work to multithreaded work, so using this keep it singlethreaded, but it allows to be moved to another thread.
+	 * @see BooleanAsyncBuilder
+	 * @return a AsyncBuilder
+	 */
+	default BooleanAsyncBuilder asAsync() {
+		return new BooleanAsyncBuilder(this);
+	}
+
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to convert a Iterable to something else.
+	 * @param mapper the mapping function
+	 * @param <E> The return type.
+	 * @return a new Iterable that returns the desired result
+	 */
+	default <E> ObjectIterable<E> map(BooleanFunction<E> mapper) {
+		return BooleanIterables.map(this, mapper);
+	}
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to convert a Iterable to something else.
+	 * @param mapper the flatMapping function
+	 * @param <V> The return type supplier.
+	 * @param <E> The return type.
+	 * @return a new Iterable that returns the desired result
+	 * @note does not support toBooleanArray optimizations.
+	 */
+	default <E, V extends Iterable<E>> ObjectIterable<E> flatMap(BooleanFunction<V> mapper) {
+		return BooleanIterables.flatMap(this, mapper);
+	}
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to convert a Iterable to something else.
+	 * @param mapper the flatMapping function
+	 * @param <E> The return type.
+	 * @return a new Iterable that returns the desired result
+	 * @note does not support toBooleanArray optimizations.
+	 */
+	default <E> ObjectIterable<E> arrayflatMap(BooleanFunction<E[]> mapper) {
+		return BooleanIterables.arrayFlatMap(this, mapper);
+	}
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to filter out unwanted elements
+	 * @param filter the elements that should be kept.
+	 * @return a Iterable that filtered out all unwanted elements
+	 * @note does not support toBooleanArray optimizations.
+	 */
+	default BooleanIterable filter(BooleanPredicate filter) {
+		return BooleanIterables.filter(this, filter);
+	}
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to filter out duplicated elements
+	 * @return a Iterable that filtered out all duplicated elements
+	 * @note does not support toBooleanArray optimizations.
+	 */
+	default BooleanIterable distinct() {
+		return BooleanIterables.distinct(this);
+	}
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to repeat elements a desired amount of times
+	 * @param repeats how many times the elements should be repeated
+	 * @return a Iterable that is repeating multiple times
+	 */
+	default BooleanIterable repeat(int repeats) {
+		return BooleanIterables.repeat(this, repeats);
+	}
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to limit the amount of elements
+	 * @param limit the amount of elements it should be limited to
+	 * @return a Iterable that is limited in length
+	 */
+	default BooleanIterable limit(long limit) {
+		return BooleanIterables.limit(this, limit);
+	}
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to sort the elements
+	 * @param sorter that sorts the elements.
+	 * @return a Iterable that is sorted
+	 */
+	default BooleanIterable sorted(BooleanComparator sorter) {
+		return BooleanIterables.sorted(this, sorter);
+	}
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to preview elements before they are iterated through
+	 * @param action the action that should be applied
+	 * @return a Peeked Iterable
+	 */
+	default BooleanIterable peek(BooleanConsumer action) {
+		return BooleanIterables.peek(this, action);
+	}
+	
+	/**
+	 * A Helper function to reduce the usage of Streams and allows to collect all elements
+	 * @param collection that the elements should be inserted to
+	 * @param <E> the collection type
+	 * @return the input with the desired elements
+	 */
+	default <E extends BooleanCollection> E pour(E collection) {
+		BooleanIterators.pour(iterator(), collection);
+		return collection;
+	}
+	
+	/**
+	 * A Helper function that reduces the usage of streams and allows to collect all elements as a ArrayList
+	 * @return a new ArrayList of all elements
+	 */
+	default BooleanList pourAsList() {
+		return pour(new BooleanArrayList());
+	}
+	
+	/**
+	 * A Helper function that reduces the usage of streams and allows to collect all elements as a Array
+	 * @return a new Array of all elements
+	 */
+	default boolean[] toBooleanArray() {
+		ISizeProvider prov = ISizeProvider.of(this);
+		if(prov != null) {
+			int size = prov.size();
+			if(size >= 0) {
+				boolean[] array = new boolean[size];
+				BooleanIterators.unwrap(array, iterator());
+				return array;
+			}
+		}
+		return BooleanArrays.pour(iterator());
+	}
+	
+	/**
+	 * Helper function to reduce stream usage that allows to filter for any matches.
+	 * @param filter that should be applied
+	 * @return true if any matches were found
+	 */
+	default boolean matchesAny(BooleanPredicate filter) {
+		Objects.requireNonNull(filter);
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			if(filter.test(iter.nextBoolean())) return true;
+		}
+		return false;
+	}
+	
+	/**
+	 * Helper function to reduce stream usage that allows to filter for no matches.
+	 * @param filter that should be applied
+	 * @return true if no matches were found
+	 */
+	default boolean matchesNone(BooleanPredicate filter) {
+		Objects.requireNonNull(filter);
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			if(filter.test(iter.nextBoolean())) return false;
+		}
+		return true;
+	}
+	
+	/**
+	 * Helper function to reduce stream usage that allows to filter for all matches.
+	 * @param filter that should be applied
+	 * @return true if all matches.
+	 */
+	default boolean matchesAll(BooleanPredicate filter) {
+		Objects.requireNonNull(filter);
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			if(!filter.test(iter.nextBoolean())) return false;
+		}
+		return true;
+	}
+	
+	/**
+	 * Helper function to reduce stream usage that allows to filter for the first match.
+	 * @param filter that should be applied
+	 * @return the found value or the null equivalent variant.
+	 */
+	default OptionalBoolean findFirst(BooleanPredicate filter) {
+		Objects.requireNonNull(filter);
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			boolean entry = iter.nextBoolean();
+			if(filter.test(entry)) return OptionalBoolean.of(entry);
+		}
+		return OptionalBoolean.empty();
+	}
+	
+	/**
+	 * Performs a <a href="package-summary.html#Reduction">reduction</a> on the
+     * elements of this Iterable
+	 * @param operator the operation that should be applied
+	 * @param identity the start value
+	 * @return the reduction result, returns identity if nothing was found
+	 */
+	default boolean reduce(boolean identity, BooleanBooleanUnaryOperator operator) {
+		Objects.requireNonNull(operator);
+		boolean state = identity;
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			state = operator.applyAsBoolean(state, iter.nextBoolean());
+		}
+		return state;
+	}
+	
+	/**
+	 * Performs a <a href="package-summary.html#Reduction">reduction</a> on the
+	 * elements of this Iterable
+	 * @param operator the operation that should be applied
+	 * @return the reduction result, returns null value if nothing was found
+	 */
+	default OptionalBoolean reduce(BooleanBooleanUnaryOperator operator) {
+		Objects.requireNonNull(operator);
+		boolean state = false;
+		boolean empty = true;
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			if(empty) {
+				empty = false;
+				state = iter.nextBoolean();
+				continue;
+			}
+			state = operator.applyAsBoolean(state, iter.nextBoolean());
+		}
+		return empty ? OptionalBoolean.empty() : OptionalBoolean.of(state);
+	}	
+	
+	/**
+	 * Helper function to reduce stream usage that allows to count the valid elements.
+	 * @param filter that should be applied
+	 * @return the amount of Valid Elements
+	 */
+	default int count(BooleanPredicate filter) {
+		Objects.requireNonNull(filter);
+		int result = 0;
+		for(BooleanIterator iter = iterator();iter.hasNext();) {
+			if(filter.test(iter.nextBoolean())) result++;
+		}
+		return result;
+	}
+}

src/main/java/speiger/src/collections/booleans/collections/BooleanIterator.java

@@ -0,0 +1,88 @@
+package speiger.src.collections.booleans.collections;
+
+import java.util.Iterator;
+import java.util.Objects;
+import java.util.function.Consumer;
+
+import speiger.src.collections.booleans.functions.BooleanConsumer;
+
+import speiger.src.collections.objects.functions.consumer.ObjectBooleanConsumer;
+
+/**
+ * A Type-Specific {@link Iterator} that reduces (un)boxing
+ */
+public interface BooleanIterator extends Iterator<Boolean>
+{
+	/**
+ 	* Returns the next element in the iteration.
+ 	*
+ 	* @return the next element in the iteration
+ 	* @throws java.util.NoSuchElementException if the iteration has no more elements
+ 	* @see Iterator#next()
+ 	*/
+	public boolean nextBoolean();
+	
+	/** {@inheritDoc}
+	* <p>This default implementation delegates to the corresponding type-specific function.
+	* @deprecated Please use the corresponding type-specific function instead. 
+	*/
+	@Override
+	@Deprecated
+	public default Boolean next() { return Boolean.valueOf(nextBoolean()); }
+	
+	/**
+	 * Performs the given action for each remaining element until all elements
+	 * have been processed or the action throws an exception.  Actions are
+	 * performed in the order of iteration, if that order is specified.
+	 * Exceptions thrown by the action are relayed to the caller.
+	 *
+	 * @implSpec
+	 * <p>The default implementation behaves as if:
+	 * <pre>{@code
+	 *	while (hasNext()) action.accept(nextBoolean());
+	 * }</pre>
+	 *
+	 * @param action The action to be performed for each element
+	 * @throws java.lang.NullPointerException if the specified action is null
+	 * @see Iterator#forEachRemaining(Consumer)
+	 */
+	public default void forEachRemaining(BooleanConsumer action) {
+		Objects.requireNonNull(action);
+		while(hasNext()) { action.accept(nextBoolean()); }
+	}
+	
+	/** {@inheritDoc}
+ 	* <p>This default implementation delegates to the corresponding type-specific function.
+ 	* @deprecated Please use the corresponding type-specific function instead. 
+ 	*/
+	@Deprecated
+	@Override
+	default void forEachRemaining(Consumer<? super Boolean> action) {
+		Objects.requireNonNull(action);
+		forEachRemaining(action::accept);
+	}
+	
+	/**
+	 * Helper function to reduce Lambda usage and allow for more method references, since these are faster/cleaner.
+	 * @param input the object that should be included
+	 * @param action The action to be performed for each element
+	 * @param <E> the generic type of the Object
+	 * @throws java.lang.NullPointerException if the specified action is null
+	 */
+	default <E> void forEachRemaining(E input, ObjectBooleanConsumer<E> action) {
+		Objects.requireNonNull(action);
+		while(hasNext()) { action.accept(input, nextBoolean()); }
+	}
+	
+	/**
+	 * Skips the Given amount of elements if possible. A Optimization function to skip elements faster if the implementation allows it.
+	 * @param amount the amount of elements that should be skipped
+	 * @return the amount of elements that were skipped
+	 */
+	default int skip(int amount) {
+		if(amount < 0) throw new IllegalStateException("Negative Numbers are not allowed");
+		int i = 0;
+		for(;i<amount && hasNext();nextBoolean(), i++);
+		return i;
+	}
+}

src/main/java/speiger/src/collections/booleans/collections/BooleanOrderedCollection.java

@@ -0,0 +1,40 @@
+package speiger.src.collections.booleans.collections;
+
+public interface BooleanOrderedCollection extends BooleanCollection {
+	
+	BooleanOrderedCollection reversed();
+	
+	/**
+	 * A method to add an element to the start of a collection
+	 * @param e that should be added at the start.
+	 */
+	public void addFirst(boolean e);
+	
+	/**
+	 * A method to add an element to the end of a collection
+	 * @param e that should be added at the end.
+	 */
+	public void addLast(boolean e);
+	
+	/**
+	 * A method to get the first element in the collection
+	 * @return first element in the collection
+	 */
+	public boolean getFirstBoolean();
+	/**
+	 * A method to get and remove the first element in the collection
+	 * @return first element in the collection
+	 */
+	public boolean removeFirstBoolean();
+	/**
+	 * A method to get the last element in the collection
+	 * @return last element in the collection
+	 */
+	public boolean getLastBoolean();
+	/**
+	 * A method to get and remove the last element in the collection
+	 * @return last element in the collection
+	 */
+	public boolean removeLastBoolean();
+	
+}

src/main/java/speiger/src/collections/booleans/collections/BooleanSplititerator.java

@@ -0,0 +1,19 @@
+package speiger.src.collections.booleans.collections;
+
+import java.util.Spliterator.OfPrimitive;
+import java.util.function.Consumer;
+
+import speiger.src.collections.booleans.functions.BooleanConsumer;
+
+/**
+ * A Type Specific Split-Iterator that reduces boxing/unboxing
+ * It fills the gaps of the java and uses this collection interfaces
+ */
+public interface BooleanSplititerator extends OfPrimitive<Boolean, BooleanConsumer, BooleanSplititerator>, BooleanIterator
+{
+	@Override
+	default void forEachRemaining(BooleanConsumer action) { BooleanIterator.super.forEachRemaining(action); }
+	@Override
+	@Deprecated
+	default void forEachRemaining(Consumer<? super Boolean> action) { BooleanIterator.super.forEachRemaining(action); }
+}

src/main/java/speiger/src/collections/booleans/collections/BooleanStack.java

@@ -0,0 +1,85 @@
+package speiger.src.collections.booleans.collections;
+
+import java.util.NoSuchElementException;
+
+import speiger.src.collections.utils.Stack;
+
+/**
+ * A Type-Specific {@link Stack} that reduces (un)boxing
+ */
+public interface BooleanStack
+{
+	/**
+	 * Inserts a given Object on top of the stack
+	 * @param e the Object to insert
+	 * @see Stack#push(Object)
+	 */
+	public void push(boolean e);
+	
+	/**
+	 * Helper function that pushes the top element on top of the stack again.
+	 * @throws NoSuchElementException if the stack is empty
+	 */
+	public default void pushTop() {
+		push(top());
+	}
+	
+	/**
+	 * Removes the Object on top of the stack.
+	 * @return the element that is on top of the stack
+	 * @throws ArrayIndexOutOfBoundsException if the stack is empty
+	 * @see Stack#pop()
+	 */
+	public boolean pop();
+	
+	/**
+	 * Provides the Object on top of the stack
+	 * @return the element that is on top of the stack
+	 * @throws ArrayIndexOutOfBoundsException if the stack is empty
+ 	 * @see Stack#top()
+	 */
+	public default boolean top() {
+		return peek(0);
+	}
+	
+	/**
+	 * Provides the Selected Object from the stack.
+	 * Top to bottom
+	 * @param index of the element that should be provided
+	 * @return the element that was requested
+ 	 * @throws ArrayIndexOutOfBoundsException if the index is out of bounds
+ 	 * @see Stack#peek(int)
+	 */
+	public boolean peek(int index);
+	
+	/**
+	 * Clears the stack
+	 */
+	public void clear();
+	
+	/**
+	 * Provides the amount of elements currently in the stack
+	 * @return amount of elements in the list
+	 */
+	public int size();
+	
+	/**
+	 * @return if the stack is empty
+	 */
+	public default boolean isEmpty() {
+		return size() == 0;
+	}
+	
+	/**
+	 * A method to drop the contents of the Stack without clearing the stack
+	 * @return the contents of the stack into a seperate array.
+	 */
+	public default boolean[] toBooleanArray() { return toBooleanArray(new boolean[size()]); }
+	/**
+	 * A method to drop the contents of the Stack without clearing the stack
+	 * @param input where the elements should be inserted to. If it does not fit then it creates a new appropiatly created array
+	 * @return the contents of the stack into a seperate array.
+	 * @note if the Type is generic then a Object Array is created instead of a Type Array
+	 */
+	public boolean[] toBooleanArray(boolean[] input);
+}

src/main/java/speiger/src/collections/booleans/functions/BooleanComparator.java

@@ -0,0 +1,70 @@
+package speiger.src.collections.booleans.functions;
+
+import java.util.Comparator;
+import java.util.Objects;
+
+/**
+ * Type-Specific Class for Comparator to reduce (un)boxing
+ */
+public interface BooleanComparator extends Comparator<Boolean> 
+{
+	/**
+	 * Type-Specific compare function to reduce (un)boxing
+	 * @param o1 the first object to be compared.
+	 * @param o2 the second object to be compared.
+	 * @return a negative integer, zero, or a positive integer as the first argument is less than, equal to, or greater than the second.
+	 * @see Comparator#compare(Object, Object)
+	 */
+	int compare(boolean o1, boolean o2);
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default int compare(Boolean o1, Boolean o2) {
+		return compare(o1.booleanValue(), o2.booleanValue());
+	}
+	
+	/**
+	 * A Wrapper function to convert a Non-Type-Specific Comparator to a Type-Specific-Comparator
+	 * @param c comparator to convert
+	 * @return the wrapper of the comparator
+	 * @throws NullPointerException if the comparator is null
+	 */
+	public static BooleanComparator of(Comparator<Boolean> c) {
+		Objects.requireNonNull(c);
+		return (K, V) -> c.compare(Boolean.valueOf(K), Boolean.valueOf(V));
+	}
+	
+	@Override
+	public default BooleanComparator reversed() {
+		return new Reversed(this);
+	}
+	
+	/**
+	 * A Type Specific Reversed Comparator to reduce boxing/unboxing
+	 */
+	static class Reversed implements BooleanComparator
+	{
+		BooleanComparator original;
+		
+		/**
+		 * default constructor
+		 * @param original that is going to be reversed
+		 */
+		public Reversed(BooleanComparator original) {
+			this.original = original;
+		}
+		
+		public int compare(boolean o1, boolean o2) {
+			return original.compare(o2, o1);
+		}
+		
+		@Override
+		public BooleanComparator reversed() {
+			return original;
+		}
+	}
+}

src/main/java/speiger/src/collections/booleans/functions/BooleanConsumer.java

@@ -0,0 +1,48 @@
+package speiger.src.collections.booleans.functions;
+
+import java.util.Objects;
+import java.util.function.Consumer;
+/**
+ * Type-Specific Consumer interface that reduces (un)boxing and allows to merge other consumer types into this interface
+ */
+@FunctionalInterface
+public interface BooleanConsumer extends Consumer<Boolean>
+{
+	/**
+	 * Type-Specific function to reduce (un)boxing. 
+	 * Performs this operation on the given argument.
+	 *
+	 * @param t the input argument
+	 */
+	void accept(boolean t);
+	
+	/**
+	 * Type Specific sequencing method to reduce boxing/unboxing.
+	 * @param after a operation that should be performed afterwards
+	 * @return a sequenced consumer that does 2 operations
+	 * @throws NullPointerException if after is null
+	 */
+	public default BooleanConsumer andThen(BooleanConsumer after) {
+		Objects.requireNonNull(after);
+		return T -> {accept(T); after.accept(T);};
+	}
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void accept(Boolean t) { accept(t.booleanValue()); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+ 	 * @deprecated Please use the corresponding type-specific function instead. 
+ 	 */
+	@Override
+	@Deprecated
+	default BooleanConsumer andThen(Consumer<? super Boolean> after) {
+		Objects.requireNonNull(after);
+		return T -> {accept(T); after.accept(Boolean.valueOf(T));};
+	}
+}

src/main/java/speiger/src/collections/booleans/functions/BooleanSupplier.java

@@ -0,0 +1,12 @@
+package speiger.src.collections.booleans.functions;
+
+/**
+ * Type-Specific Supplier interface that reduces (un)boxing and allows to merge other consumer types into this interface
+ */
+public interface BooleanSupplier
+{
+	/**
+	 * @return the supplied value
+	 */
+	public boolean getAsBoolean();
+}

src/main/java/speiger/src/collections/booleans/functions/BooleanTask.java

@@ -0,0 +1,87 @@
+package speiger.src.collections.booleans.functions;
+
+import java.util.concurrent.RunnableFuture;
+import java.util.concurrent.CancellationException;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.TimeoutException;
+
+/**
+ * 
+ * A Type Specific Task interface that allows you to keep track of the task that is currently running.<br>
+ * It extends Runnable future and supports said functions but also provides quality of life functions like:<br>
+ * 
+ * - isSuccesfull: which allows to detect if the task was completed properly and not interrupted or crashed.
+ * - pause/resume: which allows to pause/resume the task at any moment, making it easier to create thread-safe actions.
+ */
+public interface BooleanTask extends RunnableFuture<Boolean> {
+	/**
+	 * Helper function to detect if the task is currently paused.
+	 * @return true if paused
+	 */
+	public boolean isPaused();
+	
+	/**
+	 * Pauses the task, which lets the thread finish without completing the task.
+	 * Tasks are written in the way where they can pause without any issues.
+	 * This won't be instant, as this function is applied asynchronous and doesn't check if the thread paused.
+	 * So make sure it had the time to pause.
+	 */
+	public void pause();
+	
+	/**
+	 * Pauses the task, which lets the thread finish without completing the task.
+	 * Tasks are written in the way where they can pause without any issues.
+	 * This won't be instant, as this function is applied asynchronous.
+	 * It will await the pausing of the task.
+	 */
+	public void awaitPausing();
+	
+	/**
+	 * Continues the task if it wasn't already completed.
+	 * This is done by resubmitting the task to the executor provided.
+	 */
+	public void resume();
+	
+	/**
+	 * Quality of life function that allows to detect if no cancellation/exception was applied to this task and it completed on its own.
+	 * @return true if it was properly completed
+	 */
+	public boolean isSuccessful();
+	
+	/**
+	 * A Type Specific get method that allows to reduce (un)boxing of primtives.
+	 * 
+	 * Waits if necessary for the computation to complete, and then
+	 * retrieves its result.
+	 *
+	 * @return the computed result as primitive
+	 * @throws CancellationException if the computation was cancelled
+	 * @throws ExecutionException if the computation threw an exception
+	 * @throws InterruptedException if the current thread was interrupted
+	 * while waiting
+	 */
+	public boolean getBoolean() throws InterruptedException, ExecutionException;
+
+	/**
+	 * Waits if necessary for at most the given time for the computation
+	 * to complete, and then retrieves its result, if available.
+	 *
+	 * @param timeout the maximum time to wait
+	 * @param unit the time unit of the timeout argument
+	 * @return the computed result as primitive
+	 * @throws CancellationException if the computation was cancelled
+	 * @throws ExecutionException if the computation threw an exception
+	 * @throws InterruptedException if the current thread was interrupted while waiting
+	 * @throws TimeoutException if the wait timed out
+	 */
+	public boolean getBoolean(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException;
+	
+	@Override
+	@Deprecated
+	public default Boolean get() throws InterruptedException, ExecutionException { return Boolean.valueOf(getBoolean()); }
+	
+	@Override
+	@Deprecated
+	public default Boolean get(long timeout, TimeUnit unit) throws InterruptedException, ExecutionException, TimeoutException { return Boolean.valueOf(getBoolean(timeout, unit)); }
+}

src/main/java/speiger/src/collections/booleans/functions/OptionalBoolean.java

@@ -0,0 +1,89 @@
+package speiger.src.collections.booleans.functions;
+
+import java.util.NoSuchElementException;
+import java.util.function.Supplier;
+
+public final class OptionalBoolean {
+	private static final OptionalBoolean EMPTY = new OptionalBoolean();
+	
+	private final boolean isPresent;
+	private final boolean value;
+	
+	private OptionalBoolean() {
+		this.isPresent = false;
+		this.value = false;
+	}
+	
+	private OptionalBoolean(boolean value) {
+		this.isPresent = true;
+		this.value = value;
+	}
+	
+	public static OptionalBoolean empty() {
+		return EMPTY;
+	}
+	
+	public static OptionalBoolean of(boolean value) {
+		return new OptionalBoolean(value);
+	}
+	
+	public boolean getAsBoolean() {
+		if(!isPresent) throw new NoSuchElementException("No value present");
+		return value;
+	}
+	
+	public boolean isPresent() {
+		return isPresent;
+	}
+	
+	public boolean isEmpty() {
+		return !isPresent;
+	}
+	
+	public void ifPresent(BooleanConsumer consumer) {
+		if(isPresent) consumer.accept(value);
+	}
+	
+    public void ifPresentOrElse(BooleanConsumer action, Runnable emptyAction) {
+        if (isPresent) action.accept(value);
+        else emptyAction.run();
+    }
+	
+	public boolean orElse(boolean other) {
+		return isPresent ? value : other;
+	}
+	
+	public boolean orElseGet(BooleanSupplier other) {
+		return isPresent ? value : other.getAsBoolean();
+	}
+	
+	public boolean orElseThrow() {
+        if (!isPresent) throw new NoSuchElementException("No value present");
+		return value;
+	}
+	
+    public <X extends Throwable> boolean orElseThrow(Supplier<? extends X> exceptionSupplier) throws X {
+    	if(isPresent) return value;
+    	else throw exceptionSupplier.get();
+    }
+    
+    @Override
+    public boolean equals(Object obj) {
+    	if(obj == this) return true;
+    	if(obj instanceof OptionalBoolean) {
+    		OptionalBoolean other = (OptionalBoolean)obj;
+    		return (isPresent && other.isPresent ? value == other.value : isPresent == other.isPresent);
+    	}
+    	return false;
+    }
+    
+    @Override
+    public int hashCode() {
+    	return isPresent ? Boolean.hashCode(value) : 0;
+    }
+    
+    @Override
+    public String toString() {
+    	return isPresent ? "OptionalBoolean["+value+"]" : "OptionalBoolean.empty";
+    }
+}

src/main/java/speiger/src/collections/booleans/functions/consumer/BooleanBooleanConsumer.java

@@ -0,0 +1,49 @@
+package speiger.src.collections.booleans.functions.consumer;
+
+import java.util.Objects;
+import java.util.function.BiConsumer;
+
+/**
+ * A Type Specific BiConsumer class to reduce boxing/unboxing and that fills the gaps that java has.
+ */
+public interface BooleanBooleanConsumer extends BiConsumer<Boolean, Boolean>
+{
+	/**
+	 * A Type Specific operation method to reduce boxing/unboxing
+	 * Performs this operation on the given arguments.
+	 *
+	 * @param k the first input argument
+	 * @param v the second input argument
+	 */
+	void accept(boolean k, boolean v);
+	
+	/**
+	 * Type Specific sequencing method to reduce boxing/unboxing.
+	 * @param after a operation that should be performed afterwards
+	 * @return a sequenced biconsumer that does 2 operations
+	 * @throws NullPointerException if after is null
+	 */
+	public default BooleanBooleanConsumer andThen(BooleanBooleanConsumer after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(K, V);};
+	}
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void accept(Boolean k, Boolean v) { accept(k.booleanValue(), v.booleanValue()); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+ 	 * @deprecated Please use the corresponding type-specific function instead. 
+ 	 */
+	@Override
+	@Deprecated
+	default BooleanBooleanConsumer andThen(BiConsumer<? super Boolean, ? super Boolean> after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(Boolean.valueOf(K), Boolean.valueOf(V));};
+	}
+}

src/main/java/speiger/src/collections/booleans/functions/consumer/BooleanByteConsumer.java

@@ -0,0 +1,49 @@
+package speiger.src.collections.booleans.functions.consumer;
+
+import java.util.Objects;
+import java.util.function.BiConsumer;
+
+/**
+ * A Type Specific BiConsumer class to reduce boxing/unboxing and that fills the gaps that java has.
+ */
+public interface BooleanByteConsumer extends BiConsumer<Boolean, Byte>
+{
+	/**
+	 * A Type Specific operation method to reduce boxing/unboxing
+	 * Performs this operation on the given arguments.
+	 *
+	 * @param k the first input argument
+	 * @param v the second input argument
+	 */
+	void accept(boolean k, byte v);
+	
+	/**
+	 * Type Specific sequencing method to reduce boxing/unboxing.
+	 * @param after a operation that should be performed afterwards
+	 * @return a sequenced biconsumer that does 2 operations
+	 * @throws NullPointerException if after is null
+	 */
+	public default BooleanByteConsumer andThen(BooleanByteConsumer after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(K, V);};
+	}
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void accept(Boolean k, Byte v) { accept(k.booleanValue(), v.byteValue()); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+ 	 * @deprecated Please use the corresponding type-specific function instead. 
+ 	 */
+	@Override
+	@Deprecated
+	default BooleanByteConsumer andThen(BiConsumer<? super Boolean, ? super Byte> after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(Boolean.valueOf(K), Byte.valueOf(V));};
+	}
+}

src/main/java/speiger/src/collections/booleans/functions/consumer/BooleanCharConsumer.java

@@ -0,0 +1,49 @@
+package speiger.src.collections.booleans.functions.consumer;
+
+import java.util.Objects;
+import java.util.function.BiConsumer;
+
+/**
+ * A Type Specific BiConsumer class to reduce boxing/unboxing and that fills the gaps that java has.
+ */
+public interface BooleanCharConsumer extends BiConsumer<Boolean, Character>
+{
+	/**
+	 * A Type Specific operation method to reduce boxing/unboxing
+	 * Performs this operation on the given arguments.
+	 *
+	 * @param k the first input argument
+	 * @param v the second input argument
+	 */
+	void accept(boolean k, char v);
+	
+	/**
+	 * Type Specific sequencing method to reduce boxing/unboxing.
+	 * @param after a operation that should be performed afterwards
+	 * @return a sequenced biconsumer that does 2 operations
+	 * @throws NullPointerException if after is null
+	 */
+	public default BooleanCharConsumer andThen(BooleanCharConsumer after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(K, V);};
+	}
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void accept(Boolean k, Character v) { accept(k.booleanValue(), v.charValue()); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+ 	 * @deprecated Please use the corresponding type-specific function instead. 
+ 	 */
+	@Override
+	@Deprecated
+	default BooleanCharConsumer andThen(BiConsumer<? super Boolean, ? super Character> after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(Boolean.valueOf(K), Character.valueOf(V));};
+	}
+}

src/main/java/speiger/src/collections/booleans/functions/consumer/BooleanDoubleConsumer.java

@@ -0,0 +1,49 @@
+package speiger.src.collections.booleans.functions.consumer;
+
+import java.util.Objects;
+import java.util.function.BiConsumer;
+
+/**
+ * A Type Specific BiConsumer class to reduce boxing/unboxing and that fills the gaps that java has.
+ */
+public interface BooleanDoubleConsumer extends BiConsumer<Boolean, Double>
+{
+	/**
+	 * A Type Specific operation method to reduce boxing/unboxing
+	 * Performs this operation on the given arguments.
+	 *
+	 * @param k the first input argument
+	 * @param v the second input argument
+	 */
+	void accept(boolean k, double v);
+	
+	/**
+	 * Type Specific sequencing method to reduce boxing/unboxing.
+	 * @param after a operation that should be performed afterwards
+	 * @return a sequenced biconsumer that does 2 operations
+	 * @throws NullPointerException if after is null
+	 */
+	public default BooleanDoubleConsumer andThen(BooleanDoubleConsumer after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(K, V);};
+	}
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void accept(Boolean k, Double v) { accept(k.booleanValue(), v.doubleValue()); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+ 	 * @deprecated Please use the corresponding type-specific function instead. 
+ 	 */
+	@Override
+	@Deprecated
+	default BooleanDoubleConsumer andThen(BiConsumer<? super Boolean, ? super Double> after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(Boolean.valueOf(K), Double.valueOf(V));};
+	}
+}

src/main/java/speiger/src/collections/booleans/functions/consumer/BooleanFloatConsumer.java

@@ -0,0 +1,49 @@
+package speiger.src.collections.booleans.functions.consumer;
+
+import java.util.Objects;
+import java.util.function.BiConsumer;
+
+/**
+ * A Type Specific BiConsumer class to reduce boxing/unboxing and that fills the gaps that java has.
+ */
+public interface BooleanFloatConsumer extends BiConsumer<Boolean, Float>
+{
+	/**
+	 * A Type Specific operation method to reduce boxing/unboxing
+	 * Performs this operation on the given arguments.
+	 *
+	 * @param k the first input argument
+	 * @param v the second input argument
+	 */
+	void accept(boolean k, float v);
+	
+	/**
+	 * Type Specific sequencing method to reduce boxing/unboxing.
+	 * @param after a operation that should be performed afterwards
+	 * @return a sequenced biconsumer that does 2 operations
+	 * @throws NullPointerException if after is null
+	 */
+	public default BooleanFloatConsumer andThen(BooleanFloatConsumer after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(K, V);};
+	}
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+	 * @deprecated Please use the corresponding type-specific function instead. 
+	 */
+	@Override
+	@Deprecated
+	default void accept(Boolean k, Float v) { accept(k.booleanValue(), v.floatValue()); }
+	
+	/** {@inheritDoc}
+	 * <p>This default implementation delegates to the corresponding type-specific function.
+ 	 * @deprecated Please use the corresponding type-specific function instead. 
+ 	 */
+	@Override
+	@Deprecated
+	default BooleanFloatConsumer andThen(BiConsumer<? super Boolean, ? super Float> after) {
+		Objects.requireNonNull(after);
+		return (K, V) -> {accept(K, V); after.accept(Boolean.valueOf(K), Float.valueOf(V));};
+	}
+}