| var arrayPush = require('./_arrayPush'), |
| isFlattenable = require('./_isFlattenable'); |
| |
| /** |
| * The base implementation of `_.flatten` with support for restricting flattening. |
| * |
| * @private |
| * @param {Array} array The array to flatten. |
| * @param {number} depth The maximum recursion depth. |
| * @param {boolean} [predicate=isFlattenable] The function invoked per iteration. |
| * @param {boolean} [isStrict] Restrict to values that pass `predicate` checks. |
| * @param {Array} [result=[]] The initial result value. |
| * @returns {Array} Returns the new flattened array. |
| */ |
| function baseFlatten(array, depth, predicate, isStrict, result) { |
| var index = -1, |
| length = array.length; |
| |
| predicate || (predicate = isFlattenable); |
| result || (result = []); |
| |
| while (++index < length) { |
| var value = array[index]; |
| if (depth > 0 && predicate(value)) { |
| if (depth > 1) { |
| // Recursively flatten arrays (susceptible to call stack limits). |
| baseFlatten(value, depth - 1, predicate, isStrict, result); |
| } else { |
| arrayPush(result, value); |
| } |
| } else if (!isStrict) { |
| result[result.length] = value; |
| } |
| } |
| return result; |
| } |
| |
| module.exports = baseFlatten; |