| 'use strict'; |
| var $ = require('../internals/export'); |
| var toInteger = require('../internals/to-integer'); |
| var thisNumberValue = require('../internals/this-number-value'); |
| var repeat = require('../internals/string-repeat'); |
| var fails = require('../internals/fails'); |
| |
| var nativeToFixed = 1.0.toFixed; |
| var floor = Math.floor; |
| |
| var pow = function (x, n, acc) { |
| return n === 0 ? acc : n % 2 === 1 ? pow(x, n - 1, acc * x) : pow(x * x, n / 2, acc); |
| }; |
| |
| var log = function (x) { |
| var n = 0; |
| var x2 = x; |
| while (x2 >= 4096) { |
| n += 12; |
| x2 /= 4096; |
| } |
| while (x2 >= 2) { |
| n += 1; |
| x2 /= 2; |
| } return n; |
| }; |
| |
| var FORCED = nativeToFixed && ( |
| 0.00008.toFixed(3) !== '0.000' || |
| 0.9.toFixed(0) !== '1' || |
| 1.255.toFixed(2) !== '1.25' || |
| 1000000000000000128.0.toFixed(0) !== '1000000000000000128' |
| ) || !fails(function () { |
| // V8 ~ Android 4.3- |
| nativeToFixed.call({}); |
| }); |
| |
| // `Number.prototype.toFixed` method |
| // https://tc39.github.io/ecma262/#sec-number.prototype.tofixed |
| $({ target: 'Number', proto: true, forced: FORCED }, { |
| // eslint-disable-next-line max-statements |
| toFixed: function toFixed(fractionDigits) { |
| var number = thisNumberValue(this); |
| var fractDigits = toInteger(fractionDigits); |
| var data = [0, 0, 0, 0, 0, 0]; |
| var sign = ''; |
| var result = '0'; |
| var e, z, j, k; |
| |
| var multiply = function (n, c) { |
| var index = -1; |
| var c2 = c; |
| while (++index < 6) { |
| c2 += n * data[index]; |
| data[index] = c2 % 1e7; |
| c2 = floor(c2 / 1e7); |
| } |
| }; |
| |
| var divide = function (n) { |
| var index = 6; |
| var c = 0; |
| while (--index >= 0) { |
| c += data[index]; |
| data[index] = floor(c / n); |
| c = (c % n) * 1e7; |
| } |
| }; |
| |
| var dataToString = function () { |
| var index = 6; |
| var s = ''; |
| while (--index >= 0) { |
| if (s !== '' || index === 0 || data[index] !== 0) { |
| var t = String(data[index]); |
| s = s === '' ? t : s + repeat.call('0', 7 - t.length) + t; |
| } |
| } return s; |
| }; |
| |
| if (fractDigits < 0 || fractDigits > 20) throw RangeError('Incorrect fraction digits'); |
| // eslint-disable-next-line no-self-compare |
| if (number != number) return 'NaN'; |
| if (number <= -1e21 || number >= 1e21) return String(number); |
| if (number < 0) { |
| sign = '-'; |
| number = -number; |
| } |
| if (number > 1e-21) { |
| e = log(number * pow(2, 69, 1)) - 69; |
| z = e < 0 ? number * pow(2, -e, 1) : number / pow(2, e, 1); |
| z *= 0x10000000000000; |
| e = 52 - e; |
| if (e > 0) { |
| multiply(0, z); |
| j = fractDigits; |
| while (j >= 7) { |
| multiply(1e7, 0); |
| j -= 7; |
| } |
| multiply(pow(10, j, 1), 0); |
| j = e - 1; |
| while (j >= 23) { |
| divide(1 << 23); |
| j -= 23; |
| } |
| divide(1 << j); |
| multiply(1, 1); |
| divide(2); |
| result = dataToString(); |
| } else { |
| multiply(0, z); |
| multiply(1 << -e, 0); |
| result = dataToString() + repeat.call('0', fractDigits); |
| } |
| } |
| if (fractDigits > 0) { |
| k = result.length; |
| result = sign + (k <= fractDigits |
| ? '0.' + repeat.call('0', fractDigits - k) + result |
| : result.slice(0, k - fractDigits) + '.' + result.slice(k - fractDigits)); |
| } else { |
| result = sign + result; |
| } return result; |
| } |
| }); |