time-to-botec

Benchmark sampling in different programming languages
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main.js (3200B)

      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 setReadOnly = require( '@stdlib/utils/define-nonenumerable-read-only-property' );
     24 var iteratorSymbol = require( '@stdlib/symbol/iterator' );
     25 var FLOAT64_MAX_SAFE_INTEGER = require( '@stdlib/constants/float64/max-safe-integer' );
     26 var validate = require( './validate.js' );
     27 
     28 
     29 // VARIABLES //
     30 
     31 var MAX_ITER = FLOAT64_MAX_SAFE_INTEGER * 2;
     32 
     33 
     34 // MAIN //
     35 
     36 /**
     37 * Returns an iterator which generates an interleaved integer sequence.
     38 *
     39 * ## Notes
     40 *
     41 * -   If an environment supports `Symbol.iterator`, the returned iterator is iterable.
     42 *
     43 * @param {Options} [options] - function options
     44 * @param {NonNegativeInteger} [options.iter=18014398509481984] - number of iterations
     45 * @throws {TypeError} options argument must be an object
     46 * @throws {TypeError} must provide valid options
     47 * @returns {Iterator} iterator
     48 *
     49 * @example
     50 * var iter = iterIntegersSeq();
     51 *
     52 * var v = iter.next().value;
     53 * // returns 0
     54 *
     55 * v = iter.next().value;
     56 * // returns 1
     57 *
     58 * v = iter.next().value;
     59 * // returns -1
     60 *
     61 * // ...
     62 */
     63 function iterIntegersSeq( options ) {
     64 	var opts;
     65 	var iter;
     66 	var FLG;
     67 	var err;
     68 	var sgn;
     69 	var i;
     70 	var j;
     71 
     72 	opts = {
     73 		'iter': MAX_ITER
     74 	};
     75 	if ( arguments.length ) {
     76 		err = validate( opts, options );
     77 		if ( err ) {
     78 			throw err;
     79 		}
     80 	}
     81 	sgn = -1;
     82 	i = 0;
     83 	j = 0;
     84 
     85 	// Create an iterator protocol-compliant object:
     86 	iter = {};
     87 	setReadOnly( iter, 'next', next );
     88 	setReadOnly( iter, 'return', end );
     89 
     90 	// If an environment supports `Symbol.iterator`, make the iterator iterable:
     91 	if ( iteratorSymbol ) {
     92 		setReadOnly( iter, iteratorSymbol, factory );
     93 	}
     94 	return iter;
     95 
     96 	/**
     97 	* Returns an iterator protocol-compliant object containing the next iterated value.
     98 	*
     99 	* @private
    100 	* @returns {Object} iterator protocol-compliant object
    101 	*/
    102 	function next() {
    103 		i += 1;
    104 		if ( FLG || i > opts.iter ) {
    105 			return {
    106 				'done': true
    107 			};
    108 		}
    109 		if ( i === 1 ) {
    110 			return {
    111 				'value': 0,
    112 				'done': false
    113 			};
    114 		}
    115 		// Increment every other iteration...
    116 		if ( sgn < 0 ) {
    117 			j += 1;
    118 		}
    119 		sgn *= -1;
    120 		return {
    121 			'value': sgn * j,
    122 			'done': false
    123 		};
    124 	}
    125 
    126 	/**
    127 	* Finishes an iterator.
    128 	*
    129 	* @private
    130 	* @param {*} [value] - value to return
    131 	* @returns {Object} iterator protocol-compliant object
    132 	*/
    133 	function end( value ) {
    134 		FLG = true;
    135 		if ( arguments.length ) {
    136 			return {
    137 				'value': value,
    138 				'done': true
    139 			};
    140 		}
    141 		return {
    142 			'done': true
    143 		};
    144 	}
    145 
    146 	/**
    147 	* Returns a new iterator.
    148 	*
    149 	* @private
    150 	* @returns {Iterator} iterator
    151 	*/
    152 	function factory() {
    153 		return iterIntegersSeq( opts );
    154 	}
    155 }
    156 
    157 
    158 // EXPORTS //
    159 
    160 module.exports = iterIntegersSeq;