uk.co.strangeskies.collection

Class EquivalenceComparator<T>

java.lang.Object

uk.co.strangeskies.collection.EquivalenceComparator<T>

Type Parameters:

T - The type of object to compare.

All Implemented Interfaces:

java.util.Comparator<T>

public class EquivalenceComparator<T>
extends java.lang.Object
implements java.util.Comparator<T>

Provides an arbitrary total ordering over a type of object from an equality relation. Guaranteed to be a consistent ordering for a particular EquivalenceComparator, but not necessarily between different instances of EquivalenceComparator.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected class	EquivalenceComparator.IDReference

Constructor Summary

Constructors

Constructor and Description
EquivalenceComparator(java.util.function.BiPredicate<? super T,? super T> equality) Create a fresh identity comparator.

Method Summary

Modifier and Type	Method and Description
void	clean() This method can be called to prune stale references from the hash-collision map.
int	compare(T first, T second)
static <T> EquivalenceComparator<T>	identityComparator() Create a new EquivalenceComparator over the identity operation.
static <T> EquivalenceComparator<T>	naturalComparator() Create a new EquivalenceComparator over the Object.equals(java.lang.Object) equality operation.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.Comparator

comparing, comparing, comparingDouble, comparingInt, comparingLong, equals, naturalOrder, nullsFirst, nullsLast, reversed, reverseOrder, thenComparing, thenComparing, thenComparing, thenComparingDouble, thenComparingInt, thenComparingLong

Constructor Detail

EquivalenceComparator

public EquivalenceComparator(java.util.function.BiPredicate<? super T,? super T> equality)

Create a fresh identity comparator.

Parameters:

equality - The equality predicate with respect to which we wish to create a consistent ordering.

Method Detail

identityComparator

public static <T> EquivalenceComparator<T> identityComparator()

Create a new EquivalenceComparator over the identity operation.

Type Parameters:

T - The type of the items to compare

Returns:

The new equality comparator instance.

naturalComparator

public static <T> EquivalenceComparator<T> naturalComparator()

Create a new EquivalenceComparator over the Object.equals(java.lang.Object) equality operation.

Type Parameters:

T - The type of the items to compare

Returns:

The new equality comparator instance.

compare

public int compare(T first,
                   T second)

Specified by:

compare in interface java.util.Comparator<T>

clean

public void clean()

This method can be called to prune stale references from the hash-collision map. It is also called automatically