time-to-botec

Benchmark sampling in different programming languages
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order.js (2246B)

      1 /**
      2 * @license Apache-2.0
      3 *
      4 * Copyright (c) 2020 The Stdlib Authors.
      5 *
      6 * Licensed under the Apache License, Version 2.0 (the "License");
      7 * you may not use this file except in compliance with the License.
      8 * You may obtain a copy of the License at
      9 *
     10 *    http://www.apache.org/licenses/LICENSE-2.0
     11 *
     12 * Unless required by applicable law or agreed to in writing, software
     13 * distributed under the License is distributed on an "AS IS" BASIS,
     14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     15 * See the License for the specific language governing permissions and
     16 * limitations under the License.
     17 */
     18 
     19 'use strict';
     20 
     21 // MODULES //
     22 
     23 var Int32Array = require( '@stdlib/array/int32' );
     24 
     25 
     26 // FUNCTIONS //
     27 
     28 /**
     29 * Returns a comparison result. If `-1`, `a` comes before `b`. If `1`, `b` comes before `a`. If `0`, the order stays the same.
     30 *
     31 * @private
     32 * @param {number} a - first number
     33 * @param {number} b - second number
     34 * @returns {boolean} comparison result
     35 */
     36 function ascending( a, b ) {
     37 	if ( a < b ) {
     38 		return -1;
     39 	}
     40 	if ( a > b ) {
     41 		return 1;
     42 	}
     43 	return 0;
     44 }
     45 
     46 /**
     47 * Returns a comparison result. If `-1`, `a` comes before `b`. If `1`, `b` comes before `a`. If `0`, the order stays the same.
     48 *
     49 * @private
     50 * @param {number} a - first number
     51 * @param {number} b - second number
     52 * @returns {boolean} comparison result
     53 */
     54 function descending( a, b ) {
     55 	if ( a < b ) {
     56 		return 1;
     57 	}
     58 	if ( a > b ) {
     59 		return -1;
     60 	}
     61 	return 0;
     62 }
     63 
     64 
     65 // MAIN //
     66 
     67 /**
     68 * Returns a permutation which rearranges input array.
     69 *
     70 * @private
     71 * @param {ArrayLike} x - input array-like object
     72 * @param {boolean} invert - controls whether to permutation that sorts input array in descending order
     73 * @returns {Array} permutation array
     74 */
     75 function order( x, invert ) {
     76 	var comparator;
     77 	var arr;
     78 	var i;
     79 
     80 	comparator = ( invert ) ? descending : ascending;
     81 	arr = new Int32Array( x.length );
     82 	for ( i = 0; i < x.length; i++ ) {
     83 		arr[ i ] = i;
     84 	}
     85 	return arr.sort( compare );
     86 
     87 	/**
     88 	* Compare the elements of the input array.
     89 	*
     90 	* @private
     91 	* @param {number} a - first number
     92 	* @param {number} b - second number
     93 	* @returns {boolean} comparison result
     94 	*/
     95 	function compare( a, b ) {
     96 		return comparator( x[a], x[b] );
     97 	}
     98 }
     99 
    100 
    101 // EXPORTS //
    102 
    103 module.exports = order;