43 lines
1.4 KiB
JavaScript
43 lines
1.4 KiB
JavaScript
'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/6.0/#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 5 - 7, and 9
|
|
if (proto !== $ArrayPrototype) { // step 8
|
|
if (!$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 2
|
|
A.length = length;
|
|
}
|
|
/* step 10, the above as a shortcut for the below
|
|
OrdinaryDefineOwnProperty(A, 'length', {
|
|
'[[Configurable]]': false,
|
|
'[[Enumerable]]': false,
|
|
'[[Value]]': length,
|
|
'[[Writable]]': true
|
|
});
|
|
*/
|
|
return A;
|
|
};
|