Lobashov_Ivan_PIBD-21_IP/Lab2/node_modules/es-abstract/2017/RawBytesToNumber.js
2024-01-10 22:39:31 +04:00

75 lines
2.2 KiB
JavaScript

'use strict';
var GetIntrinsic = require('get-intrinsic');
var callBound = require('call-bind/callBound');
var $RangeError = GetIntrinsic('%RangeError%');
var $TypeError = GetIntrinsic('%TypeError%');
var $charAt = callBound('String.prototype.charAt');
var $reverse = callBound('Array.prototype.reverse');
var $slice = callBound('Array.prototype.slice');
var hasOwnProperty = require('./HasOwnProperty');
var IsArray = require('./IsArray');
var Type = require('./Type');
var bytesAsFloat32 = require('../helpers/bytesAsFloat32');
var bytesAsFloat64 = require('../helpers/bytesAsFloat64');
var bytesAsInteger = require('../helpers/bytesAsInteger');
var every = require('../helpers/every');
var isByteValue = require('../helpers/isByteValue');
var keys = require('object-keys');
// https://262.ecma-international.org/8.0/#table-50
var TypeToSizes = {
__proto__: null,
Int8: 1,
Uint8: 1,
Uint8C: 1,
Int16: 2,
Uint16: 2,
Int32: 4,
Uint32: 4,
Float32: 4,
Float64: 8
};
// https://262.ecma-international.org/8.0/#sec-rawbytestonumber
module.exports = function RawBytesToNumber(type, rawBytes, isLittleEndian) {
if (typeof type !== 'string' || !hasOwnProperty(TypeToSizes, type)) {
throw new $TypeError('Assertion failed: `type` must be a TypedArray element type: ' + keys(TypeToSizes));
}
if (!IsArray(rawBytes) || !every(rawBytes, isByteValue)) {
throw new $TypeError('Assertion failed: `rawBytes` must be an Array of bytes');
}
if (Type(isLittleEndian) !== 'Boolean') {
throw new $TypeError('Assertion failed: `isLittleEndian` must be a Boolean');
}
var elementSize = TypeToSizes[type]; // step 1
if (rawBytes.length !== elementSize) {
// this assertion is not in the spec, but it'd be an editorial error if it were ever violated
throw new $RangeError('Assertion failed: `rawBytes` must have a length of ' + elementSize + ' for type ' + type);
}
// eslint-disable-next-line no-param-reassign
rawBytes = $slice(rawBytes, 0, elementSize);
if (!isLittleEndian) {
$reverse(rawBytes); // step 2
}
if (type === 'Float32') { // step 3
return bytesAsFloat32(rawBytes);
}
if (type === 'Float64') { // step 4
return bytesAsFloat64(rawBytes);
}
return bytesAsInteger(rawBytes, elementSize, $charAt(type, 0) === 'U', false);
};