org.stjs.javascript.SortFunction Maven / Gradle / Ivy

/**
 *  Copyright 2011 Alexandru Craciun, Eyal Kaspi
 *
 *  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 org.stjs.javascript;

import org.stjs.javascript.annotation.JavascriptFunction;
import org.stjs.javascript.annotation.Template;

@JavascriptFunction
public interface SortFunction {
	 
	/**
	 * Compares its two arguments for order. Returns a negative integer, zero, or a positive 
	 * integer as the first argument is less than, equal to, or greater than the second.
	 * 
	 * The notation:
	 * 

	 * a <_CF b means comparefn(a,b) < 0
	 * 
a =_CF b means comparefn(a,b) = 0 (of either sign)
	 * 
a >_CF b means comparefn(a,b) > 0
	 * 
	 * 
	 * A function comparefn is a consistent comparison function for a set of values 
	 * S if all of the requirements below are met for all values a, 
	 * b, and c (possibly the same value) in the set S: 
	 * 
	 * 

	 * Calling comparefn(a,b) always returns the same value v when given a 
	 *     specific pair of values a and b as its two arguments. Furthermore, 
	 *     Type(v) is Number, and v is not NaN. Note that this 
	 *     implies that exactly one of a <_CF b, a =_CF b,
	 *     and a >_CF b will be true for a given pair of a and b.
	 * 
Calling comparefn(a,b) does not modify the this object 
	 * 
a =_CF a (reflexivity)
	 * 
If a =_CF b, then b =_CF a (symmetry)
	 * 
If a =_CF b and b =_CF c, then a =_CF
	 *     c (transitivity of =_CF)
	 * 
If a <_CF b and b <_CF c, then a 
	 *     <_CF c (transitivity of <_CF)
	 * 
If a >_CF b and b >_CF c, then a >_CF
	 *     c (transitivity of >_CF)
	 * 
	 * 
	 * @param a the first object to be compared
	 * @param b 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.
	 */
	@Template("invoke")
	public int $invoke(V a, V b);
}