recurse.js (1190B)
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 isArray = require( '@stdlib/assert/is-array' ); 24 25 26 // MAIN // 27 28 /** 29 * Recursively flattens an array. 30 * 31 * @private 32 * @param {Array} out - output array 33 * @param {Array} arr - input array 34 * @param {NonNegativeInteger} depth - recursion depth 35 * @returns {Array} output array 36 */ 37 function recurse( out, arr, depth ) { 38 var v; 39 var i; 40 for ( i = 0; i < arr.length; i++ ) { 41 v = arr[ i ]; 42 if ( depth && isArray( v ) ) { 43 recurse( out, v, depth-1 ); 44 } else { 45 out.push( v ); 46 } 47 } 48 return out; 49 } 50 51 52 // EXPORTS // 53 54 module.exports = recurse;