Added Identity HashMap support via Strategies

This commit is contained in:
Speiger 2021-05-22 06:08:27 +02:00
parent 7fcfecf308
commit 13b2c727fc
1 changed files with 28 additions and 0 deletions

View File

@ -6,6 +6,19 @@ package speiger.src.collections.PACKAGE.utils;
*/ */
public interface STRATEGY KEY_GENERIC_TYPE public interface STRATEGY KEY_GENERIC_TYPE
{ {
#if TYPE_OBJECT
/**
* Identity Strategy
*/
public static final STRATEGY NO_GENERIC_TYPE IDENTITY = new IdentityStrategyBRACES();
/**
* @Type(T)
* @return a IdentityStrategy that allows to emulate a IdentityHashMap
*/
public static GENERIC_KEY_BRACES STRATEGY KEY_GENERIC_TYPE identityStrategy() { return (STRATEGY<KEY_TYPE>)IDENTITY; }
#endif
/** /**
* Type Specific HashCode function * Type Specific HashCode function
* @param o the element that the hashcode is requested for (if object may be null) * @param o the element that the hashcode is requested for (if object may be null)
@ -20,4 +33,19 @@ public interface STRATEGY KEY_GENERIC_TYPE
* @return if the elements match * @return if the elements match
*/ */
public boolean equals(KEY_TYPE key, KEY_TYPE value); public boolean equals(KEY_TYPE key, KEY_TYPE value);
#if TYPE_OBJECT
/**
* A Strategy that uses Identity HashCode instead of the normal hashing function.
* This simulates a IdentityHashMap without having the need to actually implement it.
* @Type(T)
*/
public static class IdentityStrategy KEY_GENERIC_TYPE implements STRATEGY KEY_GENERIC_TYPE
{
@Override
public int hashCode(KEY_TYPE o) { return System.identityHashCode(o); }
@Override
public boolean equals(KEY_TYPE key, KEY_TYPE value) { return key == value; }
}
#endif
} }