odin-js-fundamentals-part-5/node_modules/es-abstract/helpers/fractionToBinaryString.js

34 lines
845 B
JavaScript

'use strict';
var MAX_ITER = 1075; // 1023+52 (subnormals) => BIAS+NUM_SIGNFICAND_BITS-1
var maxBits = 54; // only 53 bits for fraction
module.exports = function fractionToBitString(x) {
var str = '';
if (x === 0) {
return str;
}
var j = MAX_ITER;
var y;
// Each time we multiply by 2 and find a ones digit, add a '1'; otherwise, add a '0'..
for (var i = 0; i < MAX_ITER; i += 1) {
y = x * 2;
if (y >= 1) {
x = y - 1; // eslint-disable-line no-param-reassign
str += '1';
if (j === MAX_ITER) {
j = i; // first 1
}
} else {
x = y; // eslint-disable-line no-param-reassign
str += '0';
}
// Stop when we have no more decimals to process or in the event we found a fraction which cannot be represented in a finite number of bits...
if (y === 1 || i - j > maxBits) {
return str;
}
}
return str;
};