Added Flat/Mapping Functions for Iterables/Iterators (Object Only)

This commit is contained in:
Speiger 2021-07-21 16:32:30 +02:00
parent 0ed1208d59
commit 4a3cc66401
4 changed files with 273 additions and 2 deletions

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@ -1,6 +1,9 @@
# Changelog of versions # Changelog of versions
### Version 0.3.3
- Added: Flat/Mapping function for Iterables/Iterators to help avoid streams for cleaner looking code
### Version 0.3.2 ### Version 0.3.2
- Fixed: Map.put wasn't referring to primitive variants. - Fixed: Map.put wasn't referring to primitive variants.
- Added: ImmutableList. - Added: ImmutableList.

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@ -5,6 +5,9 @@ import java.util.Objects;
import java.util.function.Consumer; import java.util.function.Consumer;
import speiger.src.collections.PACKAGE.functions.CONSUMER; import speiger.src.collections.PACKAGE.functions.CONSUMER;
#else
import java.util.function.Function;
import speiger.src.collections.PACKAGE.utils.ITERATORS;
#endif #endif
import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR; import speiger.src.collections.PACKAGE.collections.SPLIT_ITERATOR;
import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS; import speiger.src.collections.PACKAGE.utils.SPLIT_ITERATORS;
@ -60,4 +63,38 @@ public interface ITERABLE KEY_GENERIC_TYPE extends Iterable<CLASS_TYPE>
*/ */
@Override @Override
default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createUnknownSplititerator(iterator(), 0); } default SPLIT_ITERATOR KEY_GENERIC_TYPE spliterator() { return SPLIT_ITERATORS.createUnknownSplititerator(iterator(), 0); }
#if TYPE_OBJECT
/**
* A Helper function to reduce the usage of Streams and allows to convert a Iterable to something else.
* @param map the mapping function
* @Type(E)
* @return a new Iterable that returns the desired result
*/
public default <E> ObjectIterable<E> map(Function<T, E> map) {
return ObjectIterators.map(this, map);
}
/**
* A Helper function to reduce the usage of Streams and allows to convert a Iterable to something else.
* @param map the flatMapping function
* @Type(E)
* @Type(V)
* @return a new Iterable that returns the desired result
*/
public default <E, V extends Iterable<E>> ObjectIterable<E> flatMap(Function<T, V> map) {
return ObjectIterators.flatMap(this, map);
}
/**
* A Helper function to reduce the usage of Streams and allows to convert a Iterable to something else.
* @param map the flatMapping function
* @Type(E)
* @return a new Iterable that returns the desired result
*/
public default <E> ObjectIterable<E> arrayflatMap(Function<T, E[]> map) {
return ObjectIterators.arrayFlatMap(this, map);
}
#endif
} }

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@ -2,12 +2,17 @@ package speiger.src.collections.PACKAGE.utils;
import java.util.Iterator; import java.util.Iterator;
import java.util.NoSuchElementException; import java.util.NoSuchElementException;
import java.util.function.Function;
import speiger.src.collections.PACKAGE.collections.ITERATOR; import speiger.src.collections.PACKAGE.collections.ITERATOR;
import speiger.src.collections.PACKAGE.lists.ARRAY_LIST; import speiger.src.collections.PACKAGE.lists.ARRAY_LIST;
import speiger.src.collections.PACKAGE.lists.LIST; import speiger.src.collections.PACKAGE.lists.LIST;
import speiger.src.collections.PACKAGE.lists.LIST_ITERATOR; import speiger.src.collections.PACKAGE.lists.LIST_ITERATOR;
import speiger.src.collections.PACKAGE.collections.BI_ITERATOR; import speiger.src.collections.PACKAGE.collections.BI_ITERATOR;
import speiger.src.collections.PACKAGE.collections.COLLECTION; import speiger.src.collections.PACKAGE.collections.COLLECTION;
#if TYPE_OBJECT
import speiger.src.collections.PACKAGE.collections.ITERABLE;
#endif
/** /**
* A Helper class for Iterators * A Helper class for Iterators
@ -81,7 +86,84 @@ public class ITERATORS
public static GENERIC_KEY_BRACES LIST_ITERATOR KEY_GENERIC_TYPE unmodifiable(LIST_ITERATOR KEY_GENERIC_TYPE iterator) { public static GENERIC_KEY_BRACES LIST_ITERATOR KEY_GENERIC_TYPE unmodifiable(LIST_ITERATOR KEY_GENERIC_TYPE iterator) {
return iterator instanceof UnmodifiableListIterator ? iterator : new UnmodifiableListIteratorBRACES(iterator); return iterator instanceof UnmodifiableListIterator ? iterator : new UnmodifiableListIteratorBRACES(iterator);
} }
/**
#if TYPE_OBJECT
/**
* A Helper function that maps a Iterable into a new Type.
* @param iterable the iterable that should be mapped
* @param mapper the function that decides what the result turns into.
* @Type(T)
* @Type(E)
* @return a iterable that is mapped to a new result
*/
public static <T, E> ITERABLE<T> map(ITERABLE<E> iterable, Function<E, T> mapper) {
return new MappedIterableBRACES(iterable, mapper);
}
/**
* A Helper function that maps a Iterator into a new Type.
* @param iterator that should be mapped
* @param mapper the function that decides what the result turns into.
* @Type(T)
* @Type(E)
* @return a iterator that is mapped to a new result
*/
public static <T, E> ITERATOR<T> map(ITERATOR<E> iterator, Function<E, T> mapper) {
return new MappedIteratorBRACES(iterator, mapper);
}
/**
* A Helper function that flatMaps a Iterable into a new Type.
* @param iterable the iterable that should be flatMapped
* @param mapper the function that decides what the result turns into.
* @Type(T)
* @Type(V)
* @Type(E)
* @return a iterable that is flatMapped to a new result
*/
public static <T, E, V extends Iterable<T>> ITERABLE<T> flatMap(ITERABLE<E> iterable, Function<E, V> mapper) {
return new FlatMappedIterableBRACES(iterable, mapper);
}
/**
* A Helper function that flatMaps a Iterable into a new Type.
* @param iterable the iterable that should be flatMapped
* @param mapper the function that decides what the result turns into.
* @Type(T)
* @Type(E)
* @return a iterable that is flatMapped to a new result
*/
public static <T, E> ITERABLE<T> arrayFlatMap(ITERABLE<E> iterable, Function<E, T[]> mapper) {
return new FlatMappedArrayIterableBRACES(iterable, mapper);
}
/**
* A Helper function that flatMaps a Iterator into a new Type.
* @param iterator that should be flatMapped
* @param mapper the function that decides what the result turns into.
* @Type(T)
* @Type(V)
* @Type(E)
* @return a iterator that is flatMapped to a new result
*/
public static <T, E, V extends Iterable<T>> ITERATOR<T> flatMap(ITERATOR<E> iterator, Function<E, V> mapper) {
return new FlatMappedIteratorBRACES(iterator, mapper);
}
/**
* A Helper function that flatMaps a Iterator into a new Type.
* @param iterator that should be flatMapped
* @param mapper the function that decides what the result turns into.
* @Type(T)
* @Type(E)
* @return a iterator that is flatMapped to a new result
*/
public static <T, E> ITERATOR<T> arrayFlatMap(ITERATOR<E> iterator, Function<E, T[]> mapper) {
return new FlatMappedArrayIteratorBRACES(iterator, mapper);
}
#endif
/**
* Helper function to convert a Object Iterator into a Primitive Iterator * Helper function to convert a Object Iterator into a Primitive Iterator
* @param iterator that should be converted to a unboxing iterator * @param iterator that should be converted to a unboxing iterator
* @ArrayType(T) * @ArrayType(T)
@ -596,4 +678,154 @@ public class ITERATORS
return amount - left; return amount - left;
} }
} }
#if TYPE_OBJECT
private static class MappedIterable<E, T> implements ITERABLE<T>
{
ITERABLE<E> iterable;
Function<E, T> mapper;
MappedIterable(ITERABLE<E> iterable, Function<E, T> mapper) {
this.iterable = iterable;
this.mapper = mapper;
}
public ITERATOR<T> iterator() {
return new MappedIterator<>(iterable.iterator(), mapper);
}
}
private static class MappedIterator<E, T> implements ITERATOR<T>
{
ITERATOR<E> iterator;
Function<E, T> mapper;
MappedIterator(ITERATOR<E> iterator, Function<E, T> mapper) {
this.iterator = iterator;
this.mapper = mapper;
}
@Override
public boolean hasNext() {
return iterator.hasNext();
}
@Override
public KEY_TYPE NEXT() {
return mapper.apply(iterator.NEXT());
}
@Override
public int skip(int amount) {
return iterator.skip(amount);
}
}
private static class FlatMappedIterable<E, T, V extends Iterable<T>> implements ITERABLE<T>
{
ITERABLE<E> iterable;
Function<E, V> mapper;
FlatMappedIterable(ITERABLE<E> iterable, Function<E, V> mapper) {
this.iterable = iterable;
this.mapper = mapper;
}
@Override
public ITERATOR<T> iterator() {
return new FlatMappedIterator<>(iterable.iterator(), mapper);
}
}
private static class FlatMappedArrayIterable<E, T> implements ITERABLE<T>
{
ITERABLE<E> iterable;
Function<E, T[]> mapper;
FlatMappedArrayIterable(ITERABLE<E> iterable, Function<E, T[]> mapper) {
this.iterable = iterable;
this.mapper = mapper;
}
@Override
public ITERATOR<T> iterator() {
return new FlatMappedArrayIterator<>(iterable.iterator(), mapper);
}
}
private static class FlatMappedIterator<E, T, V extends Iterable<T>> implements ITERATOR<T>
{
ITERATOR<E> iterator;
Iterator<T> last = null;
Function<E, V> mapper;
boolean foundNext = false;
FlatMappedIterator(ITERATOR<E> iterator, Function<E, V> mapper) {
this.iterator = iterator;
this.mapper = mapper;
}
void compute() {
if(foundNext) return;
foundNext = true;
while(iterator.hasNext())
{
if(last != null && last.hasNext()) return;
last = mapper.apply(iterator.next()).iterator();
}
}
@Override
public boolean hasNext() {
compute();
return last != null && last.hasNext();
}
@Override
public KEY_TYPE NEXT() {
if(!hasNext()) throw new IllegalStateException("End of Iterator");
KEY_TYPE result = last.next();
foundNext = false;
return result;
}
}
private static class FlatMappedArrayIterator<E, T> implements ITERATOR<T>
{
ITERATOR<E> iterator;
Iterator<T> last = null;
Function<E, T[]> mapper;
boolean foundNext = false;
FlatMappedArrayIterator(ITERATOR<E> iterator, Function<E, T[]> mapper) {
this.iterator = iterator;
this.mapper = mapper;
}
void compute() {
if(foundNext) return;
foundNext = true;
while(iterator.hasNext())
{
if(last != null && last.hasNext()) return;
last = wrap(mapper.apply(iterator.next()));
}
}
@Override
public boolean hasNext() {
compute();
return last != null && last.hasNext();
}
@Override
public T next() {
if(!hasNext()) throw new IllegalStateException("End of Iterator");
KEY_TYPE result = last.next();
foundNext = false;
return result;
}
}
#endif
} }

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@ -51,7 +51,6 @@ public abstract class BaseIntSortedSetTest extends BaseIntCollectionTest
IntSortedSet set = create(TEST_ARRAY); IntSortedSet set = create(TEST_ARRAY);
Assert.assertEquals(set.pollFirstInt(), 0); Assert.assertEquals(set.pollFirstInt(), 0);
Assert.assertEquals(set.pollLastInt(), 99); Assert.assertEquals(set.pollLastInt(), 99);
} }
} }