blob: e218b1dcb8d282f671fdd28f7aebd6d85f155cc2 [file] [log] [blame]
'use strict';
var isArray = require('../internals/is-array');
var toLength = require('../internals/to-length');
var bind = require('../internals/bind-context');
// `FlattenIntoArray` abstract operation
// https://tc39.github.io/proposal-flatMap/#sec-FlattenIntoArray
var flattenIntoArray = function (target, original, source, sourceLen, start, depth, mapper, thisArg) {
var targetIndex = start;
var sourceIndex = 0;
var mapFn = mapper ? bind(mapper, thisArg, 3) : false;
var element;
while (sourceIndex < sourceLen) {
if (sourceIndex in source) {
element = mapFn ? mapFn(source[sourceIndex], sourceIndex, original) : source[sourceIndex];
if (depth > 0 && isArray(element)) {
targetIndex = flattenIntoArray(target, original, element, toLength(element.length), targetIndex, depth - 1) - 1;
} else {
if (targetIndex >= 0x1FFFFFFFFFFFFF) throw TypeError('Exceed the acceptable array length');
target[targetIndex] = element;
}
targetIndex++;
}
sourceIndex++;
}
return targetIndex;
};
module.exports = flattenIntoArray;