Initial Save

node_modules/es-abstract/helpers/valueToFloat64Bytes.js

@@ -0,0 +1,83 @@
+'use strict';
+
+var GetIntrinsic = require('get-intrinsic');
+
+var $parseInt = GetIntrinsic('%parseInt%');
+var $abs = require('math-intrinsics/abs');
+var $floor = require('math-intrinsics/floor');
+var isNegativeZero = require('math-intrinsics/isNegativeZero');
+
+var callBound = require('call-bound');
+
+var $strIndexOf = callBound('String.prototype.indexOf');
+var $strSlice = callBound('String.prototype.slice');
+
+var fractionToBitString = require('../helpers/fractionToBinaryString');
+var intToBinString = require('../helpers/intToBinaryString');
+
+var float64bias = 1023;
+
+var elevenOnes = '11111111111';
+var elevenZeroes = '00000000000';
+var fiftyOneZeroes = elevenZeroes + elevenZeroes + elevenZeroes + elevenZeroes + '0000000';
+
+// IEEE 754-1985
+module.exports = function valueToFloat64Bytes(value, isLittleEndian) {
+	var signBit = value < 0 || isNegativeZero(value) ? '1' : '0';
+	var exponentBits;
+	var significandBits;
+
+	if (isNaN(value)) {
+		exponentBits = elevenOnes;
+		significandBits = '1' + fiftyOneZeroes;
+	} else if (!isFinite(value)) {
+		exponentBits = elevenOnes;
+		significandBits = '0' + fiftyOneZeroes;
+	} else if (value === 0) {
+		exponentBits = elevenZeroes;
+		significandBits = '0' + fiftyOneZeroes;
+	} else {
+		value = $abs(value); // eslint-disable-line no-param-reassign
+
+		// Isolate the integer part (digits before the decimal):
+		var integerPart = $floor(value);
+
+		var intBinString = intToBinString(integerPart); // bit string for integer part
+		var fracBinString = fractionToBitString(value - integerPart); // bit string for fractional part
+
+		var numberOfBits;
+		// find exponent needed to normalize integer+fractional parts
+		if (intBinString) {
+			exponentBits = intBinString.length - 1; // move the decimal to the left
+		} else {
+			var first1 = $strIndexOf(fracBinString, '1');
+			if (first1 > -1) {
+				numberOfBits = first1 + 1;
+			}
+			exponentBits = -numberOfBits; // move the decimal to the right
+		}
+
+		significandBits = intBinString + fracBinString;
+		if (exponentBits < 0) {
+			// subnormals
+			if (exponentBits <= -float64bias) {
+				numberOfBits = float64bias - 1; // limit number of removed bits
+			}
+			significandBits = $strSlice(significandBits, numberOfBits); // remove all leading 0s and the first 1 for normal values; for subnormals, remove up to `float64bias - 1` leading bits
+		} else {
+			significandBits = $strSlice(significandBits, 1); // remove the leading '1' (implicit/hidden bit)
+		}
+		exponentBits = $strSlice(elevenZeroes + intToBinString(exponentBits + float64bias), -11); // Convert the exponent to a bit string
+
+		significandBits = $strSlice(significandBits + fiftyOneZeroes + '0', 0, 52); // fill in any trailing zeros and ensure we have only 52 fraction bits
+	}
+
+	var bits = signBit + exponentBits + significandBits;
+	var rawBytes = [];
+	for (var i = 0; i < 8; i++) {
+		var targetIndex = isLittleEndian ? 8 - i - 1 : i;
+		rawBytes[targetIndex] = $parseInt($strSlice(bits, i * 8, (i + 1) * 8), 2);
+	}
+
+	return rawBytes;
+};