GoScrobble/web/node_modules/es5-ext/array/#/concat/shim.js

45 lines
1.2 KiB
JavaScript

"use strict";
var isPlainArray = require("../../is-plain-array")
, toPosInt = require("../../../number/to-pos-integer")
, isObject = require("../../../object/is-object")
, isConcatSpreadable = require("es6-symbol").isConcatSpreadable
, isArray = Array.isArray
, concat = Array.prototype.concat
, forEach = Array.prototype.forEach
, isSpreadable;
isSpreadable = function (value) {
if (!value) return false;
if (!isObject(value)) return false;
if (value[isConcatSpreadable] !== undefined) {
return Boolean(value[isConcatSpreadable]);
}
return isArray(value);
};
// eslint-disable-next-line no-unused-vars
module.exports = function (item/*, …items*/) {
var result;
if (!this || !isArray(this) || isPlainArray(this)) {
return concat.apply(this, arguments);
}
result = new this.constructor();
if (isSpreadable(this)) {
forEach.call(this, function (val, i) { result[i] = val; });
} else {
result[0] = this;
}
forEach.call(arguments, function (arg) {
var base;
if (isSpreadable(arg)) {
base = result.length;
result.length += toPosInt(arg.length);
forEach.call(arg, function (val, i) { result[base + i] = val; });
return;
}
result.push(arg);
});
return result;
};