| 'use strict'; |
| |
| var $SyntaxError = require('es-errors/syntax'); |
| var $TypeError = require('es-errors/type'); |
| |
| var GetValueFromBuffer = require('./GetValueFromBuffer'); |
| var IsDetachedBuffer = require('./IsDetachedBuffer'); |
| var IsInteger = require('./IsInteger'); |
| |
| var isNegativeZero = require('../helpers/isNegativeZero'); |
| |
| var typedArrayLength = require('typed-array-length'); |
| var typedArrayBuffer = require('typed-array-buffer'); |
| var typedArrayByteOffset = require('typed-array-byte-offset'); |
| var whichTypedArray = require('which-typed-array'); |
| |
| var tableTAO = require('./tables/typed-array-objects'); |
| |
| // https://262.ecma-international.org/6.0/#sec-integerindexedelementget |
| |
| module.exports = function IntegerIndexedElementGet(O, index) { |
| if (typeof index !== 'number') { |
| throw new $TypeError('`index` must be a Number'); // step 1 |
| } |
| var arrayTypeName = whichTypedArray(O); // step 10 |
| if (!arrayTypeName) { |
| throw new $TypeError('`O` must be a TypedArray'); // step 2 |
| } |
| if (arrayTypeName === 'BigInt64Array' || arrayTypeName === 'BigUint64Array') { |
| throw new $SyntaxError('BigInt64Array and BigUint64Array do not exist until ES2020'); |
| } |
| |
| var buffer = typedArrayBuffer(O); // step 3 |
| |
| if (IsDetachedBuffer(buffer)) { |
| throw new $TypeError('`O` has a detached buffer'); // step 4 |
| } |
| |
| if (!IsInteger(index) || isNegativeZero(index)) { |
| return void undefined; // steps 5 - 6 |
| } |
| |
| var length = typedArrayLength(O); // step 7 |
| |
| if (index < 0 || index >= length) { |
| return void undefined; // step 8 |
| } |
| |
| var offset = typedArrayByteOffset(O); // step 9 |
| |
| var elementType = tableTAO.name['$' + arrayTypeName]; // step 13 |
| |
| var elementSize = tableTAO.size['$' + elementType]; // step 11 |
| |
| var indexedPosition = (index * elementSize) + offset; // step 12 |
| |
| return GetValueFromBuffer(buffer, indexedPosition, elementType); // step 14 |
| }; |