| 'use strict'; |
| |
| var GetIntrinsic = require('get-intrinsic'); |
| |
| var $ArrayPrototype = GetIntrinsic('%Array.prototype%'); |
| var $RangeError = require('es-errors/range'); |
| var $SyntaxError = require('es-errors/syntax'); |
| var $TypeError = require('es-errors/type'); |
| var isInteger = require('math-intrinsics/isInteger'); |
| var MAX_ARRAY_LENGTH = require('math-intrinsics/constants/maxArrayLength'); |
| var $setProto = require('set-proto'); |
| |
| // https://262.ecma-international.org/12.0/#sec-arraycreate |
| |
| module.exports = function ArrayCreate(length) { |
| if (!isInteger(length) || length < 0) { |
| throw new $TypeError('Assertion failed: `length` must be an integer Number >= 0'); |
| } |
| if (length > MAX_ARRAY_LENGTH) { |
| throw new $RangeError('length is greater than (2**32 - 1)'); |
| } |
| var proto = arguments.length > 1 ? arguments[1] : $ArrayPrototype; |
| var A = []; // steps 3, 5 |
| if (proto !== $ArrayPrototype) { // step 4 |
| if (!$setProto) { |
| throw new $SyntaxError('ArrayCreate: a `proto` argument that is not `Array.prototype` is not supported in an environment that does not support setting the [[Prototype]]'); |
| } |
| $setProto(A, proto); |
| } |
| if (length !== 0) { // bypasses the need for step 6 |
| A.length = length; |
| } |
| /* step 6, the above as a shortcut for the below |
| OrdinaryDefineOwnProperty(A, 'length', { |
| '[[Configurable]]': false, |
| '[[Enumerable]]': false, |
| '[[Value]]': length, |
| '[[Writable]]': true |
| }); |
| */ |
| return A; |
| }; |