'use strict';
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var GetIntrinsic = require('get-intrinsic');
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var $floor = GetIntrinsic('%Math.floor%');
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var $log = GetIntrinsic('%Math.log%');
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var $log2E = GetIntrinsic('%Math.LOG2E%');
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var $log2 = GetIntrinsic('%Math.log2%', true) || function log2(x) {
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return $log(x) * $log2E;
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};
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var $parseInt = GetIntrinsic('%parseInt%');
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var $pow = GetIntrinsic('%Math.pow%');
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var $TypeError = GetIntrinsic('%TypeError%');
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var callBound = require('call-bind/callBound');
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var $reverse = callBound('Array.prototype.reverse');
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var $numberToString = callBound('Number.prototype.toString');
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var $strSlice = callBound('String.prototype.slice');
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var abs = require('./abs');
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var hasOwnProperty = require('./HasOwnProperty');
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var ToInt16 = require('./ToInt16');
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var ToInt32 = require('./ToInt32');
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var ToInt8 = require('./ToInt8');
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var ToUint16 = require('./ToUint16');
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var ToUint32 = require('./ToUint32');
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var ToUint8 = require('./ToUint8');
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var ToUint8Clamp = require('./ToUint8Clamp');
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var Type = require('./Type');
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var isNaN = require('../helpers/isNaN');
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var isFinite = require('../helpers/isFinite');
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var keys = require('object-keys');
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// https://262.ecma-international.org/8.0/#table-50
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var TypeToSizes = {
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__proto__: null,
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Int8: 1,
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Uint8: 1,
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Uint8C: 1,
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Int16: 2,
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Uint16: 2,
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Int32: 4,
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Uint32: 4,
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Float32: 4,
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Float64: 8
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};
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var TypeToAO = {
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__proto__: null,
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Int8: ToInt8,
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Uint8: ToUint8,
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Uint8C: ToUint8Clamp,
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Int16: ToInt16,
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Uint16: ToUint16,
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Int32: ToInt32,
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Uint32: ToUint32
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};
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// https://262.ecma-international.org/8.0/#sec-numbertorawbytes
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module.exports = function NumberToRawBytes(type, value, isLittleEndian) {
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if (typeof type !== 'string' || !hasOwnProperty(TypeToSizes, type)) {
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throw new $TypeError('Assertion failed: `type` must be a TypedArray element type: ' + keys(TypeToSizes));
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}
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if (Type(value) !== 'Number') {
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throw new $TypeError('Assertion failed: `value` must be a Number');
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}
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if (Type(isLittleEndian) !== 'Boolean') {
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throw new $TypeError('Assertion failed: `isLittleEndian` must be a Boolean');
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}
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var rawBytes = [];
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var exponent;
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if (type === 'Float32') { // step 1
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if (isNaN(value)) {
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return isLittleEndian ? [0, 0, 192, 127] : [127, 192, 0, 0]; // hardcoded
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}
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var leastSig;
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if (value === 0) {
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leastSig = Object.is(value, -0) ? 0x80 : 0;
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return isLittleEndian ? [0, 0, 0, leastSig] : [leastSig, 0, 0, 0];
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}
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if (!isFinite(value)) {
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leastSig = value < 0 ? 255 : 127;
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return isLittleEndian ? [0, 0, 128, leastSig] : [leastSig, 128, 0, 0];
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}
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var sign = value < 0 ? 1 : 0;
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value = abs(value); // eslint-disable-line no-param-reassign
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exponent = 0;
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while (value >= 2) {
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exponent += 1;
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value /= 2; // eslint-disable-line no-param-reassign
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}
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while (value < 1) {
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exponent -= 1;
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value *= 2; // eslint-disable-line no-param-reassign
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}
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var mantissa = value - 1;
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mantissa *= $pow(2, 23);
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mantissa = $floor(mantissa);
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exponent += 127;
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exponent = exponent << 23;
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var result = sign << 31;
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result |= exponent;
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result |= mantissa;
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var byte0 = result & 255;
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result = result >> 8;
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var byte1 = result & 255;
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result = result >> 8;
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var byte2 = result & 255;
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result = result >> 8;
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var byte3 = result & 255;
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if (isLittleEndian) {
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return [byte0, byte1, byte2, byte3];
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}
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return [byte3, byte2, byte1, byte0];
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} else if (type === 'Float64') { // step 2
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if (value === 0) {
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leastSig = Object.is(value, -0) ? 0x80 : 0;
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return isLittleEndian ? [0, 0, 0, 0, 0, 0, 0, leastSig] : [leastSig, 0, 0, 0, 0, 0, 0, 0];
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}
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if (isNaN(value)) {
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return isLittleEndian ? [0, 0, 0, 0, 0, 0, 248, 127] : [127, 248, 0, 0, 0, 0, 0, 0];
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}
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if (!isFinite(value)) {
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var infBytes = value < 0 ? [0, 0, 0, 0, 0, 0, 240, 255] : [0, 0, 0, 0, 0, 0, 240, 127];
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return isLittleEndian ? infBytes : $reverse(infBytes);
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}
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var isNegative = value < 0;
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if (isNegative) { value = -value; } // eslint-disable-line no-param-reassign
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exponent = $floor($log2(value));
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var significand = (value / $pow(2, exponent)) - 1;
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var bitString = '';
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for (var i = 0; i < 52; i++) {
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significand *= 2;
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if (significand >= 1) {
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bitString += '1';
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significand -= 1;
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} else {
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bitString += '0';
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}
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}
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exponent += 1023;
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var exponentBits = $numberToString(exponent, 2);
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while (exponentBits.length < 11) { exponentBits = '0' + exponentBits; }
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var fullBitString = (isNegative ? '1' : '0') + exponentBits + bitString;
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while (fullBitString.length < 64) { fullBitString = '0' + fullBitString; }
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for (i = 0; i < 8; i++) {
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rawBytes[i] = $parseInt($strSlice(fullBitString, i * 8, (i + 1) * 8), 2);
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}
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return isLittleEndian ? $reverse(rawBytes) : rawBytes;
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} // step 3
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var n = TypeToSizes[type]; // step 3.a
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var convOp = TypeToAO[type]; // step 3.b
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var intValue = convOp(value); // step 3.c
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/*
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if (intValue >= 0) { // step 3.d
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// Let rawBytes be a List containing the n-byte binary encoding of intValue. If isLittleEndian is false, the bytes are ordered in big endian order. Otherwise, the bytes are ordered in little endian order.
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} else { // step 3.e
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// Let rawBytes be a List containing the n-byte binary 2's complement encoding of intValue. If isLittleEndian is false, the bytes are ordered in big endian order. Otherwise, the bytes are ordered in little endian order.
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}
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*/
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if (intValue < 0) {
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intValue = intValue >>> 0;
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}
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for (i = 0; i < n; i++) {
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rawBytes[isLittleEndian ? i : n - 1 - i] = intValue & 0xff;
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intValue = intValue >> 8;
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}
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return rawBytes; // step 4
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};
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