Spaces:
Configuration error
Configuration error
; | |
var GetIntrinsic = require('get-intrinsic'); | |
var $pow = GetIntrinsic('%Math.pow%'); | |
var $Number = GetIntrinsic('%Number%'); | |
var $BigInt = GetIntrinsic('%BigInt%', true); | |
module.exports = function bytesAsInteger(rawBytes, elementSize, isUnsigned, isBigInt) { | |
var Z = isBigInt ? $BigInt : $Number; | |
// this is common to both branches | |
var intValue = Z(0); | |
for (var i = 0; i < rawBytes.length; i++) { | |
intValue += Z(rawBytes[i]) * Z($pow(2, 8 * i)); | |
} | |
/* | |
Let intValue be the byte elements of rawBytes concatenated and interpreted as a bit string encoding of an unsigned little-endian binary number. | |
*/ | |
if (!isUnsigned) { // steps 5-6 | |
// Let intValue be the byte elements of rawBytes concatenated and interpreted as a bit string encoding of a binary little-endian 2's complement number of bit length elementSize × 8. | |
var bitLength = elementSize * 8; | |
if (rawBytes[elementSize - 1] & 0x80) { | |
intValue -= Z($pow(2, bitLength)); | |
} | |
} | |
return intValue; // step 7 | |
}; | |