main.js (1567B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2018 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 ctors = require( './ctors.js' ); 24 25 26 // VARIABLES // 27 28 var bool; 29 30 31 // FUNCTIONS // 32 33 /** 34 * Returns a boolean indicating if an environment is little endian. 35 * 36 * @private 37 * @returns {boolean} boolean indicating if an environment is little endian 38 * 39 * @example 40 * var bool = isLittleEndian(); 41 * // returns <boolean> 42 */ 43 function isLittleEndian() { 44 var uint16view; 45 var uint8view; 46 47 uint16view = new ctors[ 'uint16' ]( 1 ); 48 49 /* 50 * Set the uint16 view to a value having distinguishable lower and higher order words. 51 * 52 * 4660 => 0x1234 => 0x12 0x34 => '00010010 00110100' => (0x12,0x34) == (18,52) 53 */ 54 uint16view[ 0 ] = 0x1234; 55 56 // Create a uint8 view on top of the uint16 buffer: 57 uint8view = new ctors[ 'uint8' ]( uint16view.buffer ); 58 59 // If little endian, the least significant byte will be first... 60 return ( uint8view[ 0 ] === 0x34 ); 61 } 62 63 64 // MAIN // 65 66 bool = isLittleEndian(); 67 68 69 // EXPORTS // 70 71 module.exports = bool;