File size: 1,733 Bytes
4b876a7 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 | var _ = require('underscore');
var errors = require('../errors.js');
var hex = require('./hex.js');
var numhelp = require('./numhelp.js');
function validate(number)
{
if (number.length < 1 || number.match(/[^0123456789]/)) {
throw new errors.InvalidArgument('Invalid decimal number: ' + number);
}
}
function dec2bin(number)
{
validate(number);
return numhelp.unpad(hex.to.bin(dec2hex(number)));
}
function dec2oct(number)
{
validate(number);
return numhelp.unpad(hex.to.oct(dec2hex(number)));
}
function dec2dec(number)
{
validate(number);
return numhelp.unpad(number);
}
function dec2hex(number)
{
validate(number);
var array = number.split('').map(Number).reverse();
var mult = function(scalar, x) {
if (0 === scalar) return [];
var result = [];
var power = x;
while (true) {
if (scalar & 1) {
result = add(result, power);
}
if (0 === (scalar = (scalar >> 1))) break;
power = add(power, power);
}
return result;
};
var add = function(x, y) {
var ret = [], c = 0;
x = x.slice(0); /* Copy to allow same value for x and y */
y = y.slice(0); /* Copy to allow same value for x and y */
while (0 < x.length || 0 < y.length || c) {
var o = (x.shift() || 0) + (y.shift() || 0) + c;
ret.push(o % 16);
c = Math.floor(o / 16);
}
return ret;
};
var result = [ 0 ], power = [ 1 ];
_.each(array, function(digit) {
if (digit > 0) result = add(result, mult(digit, power));
power = mult(10, power);
});
return result.reverse().map(function(digit) { return digit.toString(16); }).join('');
}
exports.to = {
bin : dec2bin,
oct : dec2oct,
dec : dec2dec,
hex : dec2hex
};
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