io.fabric8.zjsonpatch.internal.collections4.Equator Maven / Gradle / Ivy
/**
* Copyright 2016 flipkart.com zjsonpatch.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.fabric8.zjsonpatch.internal.collections4;
/**
* An equation function, which determines equality between objects of type T.
*
* It is the functional sibling of {@link java.util.Comparator}; {@link Equator} is to
* {@link Object} as {@link java.util.Comparator} is to {@link java.lang.Comparable}.
*
* @param the types of object this {@link Equator} can evaluate.
* @version $Id: Equator.html -11-24 13:43:45Z tn $
* @since 4.0
*/
public interface Equator {
/**
* Evaluates the two arguments for their equality.
*
* @param o1 the first object to be equated.
* @param o2 the second object to be equated.
* @return whether the two objects are equal.
*/
boolean equate(T o1, T o2);
/**
* Calculates the hash for the object, based on the method of equality used in the equate
* method. This is used for classes that delegate their {@link Object#equals(Object) equals(Object)} method to an
* Equator (and so must also delegate their {@link Object#hashCode() hashCode()} method), or for implementations
* of {@link org.apache.commons.collections4.map.HashedMap} that use an Equator for the key objects.
*
* @param o the object to calculate the hash for.
* @return the hash of the object.
*/
int hash(T o);
}