_baseFlatten.js (1201B)
1 var arrayPush = require('./_arrayPush'), 2 isFlattenable = require('./_isFlattenable'); 3 4 /** 5 * The base implementation of `_.flatten` with support for restricting flattening. 6 * 7 * @private 8 * @param {Array} array The array to flatten. 9 * @param {number} depth The maximum recursion depth. 10 * @param {boolean} [predicate=isFlattenable] The function invoked per iteration. 11 * @param {boolean} [isStrict] Restrict to values that pass `predicate` checks. 12 * @param {Array} [result=[]] The initial result value. 13 * @returns {Array} Returns the new flattened array. 14 */ 15 function baseFlatten(array, depth, predicate, isStrict, result) { 16 var index = -1, 17 length = array.length; 18 19 predicate || (predicate = isFlattenable); 20 result || (result = []); 21 22 while (++index < length) { 23 var value = array[index]; 24 if (depth > 0 && predicate(value)) { 25 if (depth > 1) { 26 // Recursively flatten arrays (susceptible to call stack limits). 27 baseFlatten(value, depth - 1, predicate, isStrict, result); 28 } else { 29 arrayPush(result, value); 30 } 31 } else if (!isStrict) { 32 result[result.length] = value; 33 } 34 } 35 return result; 36 } 37 38 module.exports = baseFlatten;