es-abstract/2023/SetTypedArrayFromArrayLike.js

ECMAScript spec abstract operations.

'use strict';

var $RangeError = require('es-errors/range');
var $TypeError = require('es-errors/type');
var isInteger = require('math-intrinsics/isInteger');

var isTypedArray = require('is-typed-array');
var typedArrayBuffer = require('typed-array-buffer');
var typedArrayLength = require('typed-array-length');
var whichTypedArray = require('which-typed-array');

var Get = require('./Get');
var IntegerIndexedElementSet = require('./IntegerIndexedElementSet');
var IsDetachedBuffer = require('./IsDetachedBuffer');
var LengthOfArrayLike = require('./LengthOfArrayLike');
var ToObject = require('./ToObject');
var ToString = require('./ToString');

// https://262.ecma-international.org/14.0/#sec-settypedarrayfromarraylike

module.exports = function SetTypedArrayFromArrayLike(target, targetOffset, source) {
	var whichTarget = whichTypedArray(target);
	if (!whichTarget) {
		throw new $TypeError('Assertion failed: target must be a TypedArray instance');
	}

	if (targetOffset !== Infinity && (!isInteger(targetOffset) || targetOffset < 0)) {
		throw new $TypeError('Assertion failed: targetOffset must be a non-negative integer or +Infinity');
	}

	if (isTypedArray(source)) {
		throw new $TypeError('Assertion failed: source must not be a TypedArray instance');
	}

	var targetBuffer = typedArrayBuffer(target); // step 1

	if (IsDetachedBuffer(targetBuffer)) {
		throw new $TypeError('target’s buffer is detached'); // step 2
	}

	var targetLength = typedArrayLength(target); // step 3

	var src = ToObject(source); // step 4

	var srcLength = LengthOfArrayLike(src); // step 5

	if (targetOffset === Infinity) {
		throw new $RangeError('targetOffset must be a finite integer'); // step 6
	}

	if (srcLength + targetOffset > targetLength) {
		throw new $RangeError('targetOffset + srcLength must be <= target.length'); // step 7
	}

	var k = 0; // step 8

	while (k < srcLength) { // step 9
		var Pk = ToString(k); // step 9.a

		var value = Get(src, Pk); // step 9.b

		var targetIndex = targetOffset + k; // step 9.c

		IntegerIndexedElementSet(target, targetIndex, value); // step 9.d

		k += 1; // step 9.e
	}
};