main.js (1677B)
1 /** 2 * @license Apache-2.0 3 * 4 * Copyright (c) 2021 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 // MAIN // 22 23 /** 24 * Returns a regular expression to capture everything that is not a space immediately after the `function` keyword and before the first left parenthesis. 25 * 26 * @returns {RegExp} regular expression 27 * 28 * @example 29 * var RE_NATIVE_FUNCTION = reNativeFunction(); 30 * var bool = RE_NATIVE_FUNCTION.test( Date.toString() ); 31 * // returns true 32 */ 33 function reNativeFunction() { 34 var str = ''; 35 36 // Use a native function as a template: 37 str += Function.prototype.toString.call( Function ); 38 39 // Escape special RegExp characters: 40 str = str.replace( /([.*+?^=!:$(){}|[\]\/\\])/g, '\\$1' ); // eslint-disable-line no-useless-escape 41 42 // Replace any mentions of `Function` to make template generic and replace `for ...` and additional info provided in other environments, such as Rhino. 43 str = str.replace( /Function|(function).*?(?=\\\()| for .+?(?=\\\])/g, '$1.*?' ); 44 45 // Bracket the regular expression: 46 str = '^' + str + '$'; 47 48 // Create the regular expression: 49 return new RegExp( str ); 50 } 51 52 53 // EXPORTS // 54 55 module.exports = reNativeFunction;