[79a0317] | 1 | 'use strict';
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| 2 | var $ = require('../internals/export');
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| 3 | var uncurryThis = require('../internals/function-uncurry-this');
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| 4 | var toIntegerOrInfinity = require('../internals/to-integer-or-infinity');
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| 5 | var thisNumberValue = require('../internals/this-number-value');
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| 6 | var $repeat = require('../internals/string-repeat');
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| 7 | var fails = require('../internals/fails');
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| 8 |
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| 9 | var $RangeError = RangeError;
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| 10 | var $String = String;
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| 11 | var floor = Math.floor;
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| 12 | var repeat = uncurryThis($repeat);
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| 13 | var stringSlice = uncurryThis(''.slice);
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| 14 | var nativeToFixed = uncurryThis(1.0.toFixed);
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| 15 |
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| 16 | var pow = function (x, n, acc) {
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| 17 | return n === 0 ? acc : n % 2 === 1 ? pow(x, n - 1, acc * x) : pow(x * x, n / 2, acc);
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| 18 | };
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| 19 |
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| 20 | var log = function (x) {
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| 21 | var n = 0;
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| 22 | var x2 = x;
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| 23 | while (x2 >= 4096) {
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| 24 | n += 12;
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| 25 | x2 /= 4096;
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| 26 | }
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| 27 | while (x2 >= 2) {
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| 28 | n += 1;
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| 29 | x2 /= 2;
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| 30 | } return n;
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| 31 | };
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| 32 |
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| 33 | var multiply = function (data, n, c) {
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| 34 | var index = -1;
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| 35 | var c2 = c;
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| 36 | while (++index < 6) {
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| 37 | c2 += n * data[index];
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| 38 | data[index] = c2 % 1e7;
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| 39 | c2 = floor(c2 / 1e7);
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| 40 | }
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| 41 | };
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| 42 |
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| 43 | var divide = function (data, n) {
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| 44 | var index = 6;
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| 45 | var c = 0;
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| 46 | while (--index >= 0) {
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| 47 | c += data[index];
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| 48 | data[index] = floor(c / n);
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| 49 | c = (c % n) * 1e7;
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| 50 | }
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| 51 | };
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| 52 |
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| 53 | var dataToString = function (data) {
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| 54 | var index = 6;
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| 55 | var s = '';
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| 56 | while (--index >= 0) {
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| 57 | if (s !== '' || index === 0 || data[index] !== 0) {
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| 58 | var t = $String(data[index]);
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| 59 | s = s === '' ? t : s + repeat('0', 7 - t.length) + t;
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| 60 | }
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| 61 | } return s;
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| 62 | };
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| 63 |
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| 64 | var FORCED = fails(function () {
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| 65 | return nativeToFixed(0.00008, 3) !== '0.000' ||
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| 66 | nativeToFixed(0.9, 0) !== '1' ||
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| 67 | nativeToFixed(1.255, 2) !== '1.25' ||
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| 68 | nativeToFixed(1000000000000000128.0, 0) !== '1000000000000000128';
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| 69 | }) || !fails(function () {
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| 70 | // V8 ~ Android 4.3-
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| 71 | nativeToFixed({});
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| 72 | });
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| 73 |
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| 74 | // `Number.prototype.toFixed` method
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| 75 | // https://tc39.es/ecma262/#sec-number.prototype.tofixed
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| 76 | $({ target: 'Number', proto: true, forced: FORCED }, {
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| 77 | toFixed: function toFixed(fractionDigits) {
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| 78 | var number = thisNumberValue(this);
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| 79 | var fractDigits = toIntegerOrInfinity(fractionDigits);
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| 80 | var data = [0, 0, 0, 0, 0, 0];
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| 81 | var sign = '';
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| 82 | var result = '0';
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| 83 | var e, z, j, k;
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| 84 |
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| 85 | // TODO: ES2018 increased the maximum number of fraction digits to 100, need to improve the implementation
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| 86 | if (fractDigits < 0 || fractDigits > 20) throw new $RangeError('Incorrect fraction digits');
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| 87 | // eslint-disable-next-line no-self-compare -- NaN check
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| 88 | if (number !== number) return 'NaN';
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| 89 | if (number <= -1e21 || number >= 1e21) return $String(number);
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| 90 | if (number < 0) {
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| 91 | sign = '-';
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| 92 | number = -number;
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| 93 | }
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| 94 | if (number > 1e-21) {
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| 95 | e = log(number * pow(2, 69, 1)) - 69;
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| 96 | z = e < 0 ? number * pow(2, -e, 1) : number / pow(2, e, 1);
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| 97 | z *= 0x10000000000000;
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| 98 | e = 52 - e;
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| 99 | if (e > 0) {
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| 100 | multiply(data, 0, z);
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| 101 | j = fractDigits;
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| 102 | while (j >= 7) {
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| 103 | multiply(data, 1e7, 0);
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| 104 | j -= 7;
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| 105 | }
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| 106 | multiply(data, pow(10, j, 1), 0);
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| 107 | j = e - 1;
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| 108 | while (j >= 23) {
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| 109 | divide(data, 1 << 23);
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| 110 | j -= 23;
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| 111 | }
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| 112 | divide(data, 1 << j);
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| 113 | multiply(data, 1, 1);
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| 114 | divide(data, 2);
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| 115 | result = dataToString(data);
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| 116 | } else {
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| 117 | multiply(data, 0, z);
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| 118 | multiply(data, 1 << -e, 0);
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| 119 | result = dataToString(data) + repeat('0', fractDigits);
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| 120 | }
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| 121 | }
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| 122 | if (fractDigits > 0) {
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| 123 | k = result.length;
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| 124 | result = sign + (k <= fractDigits
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| 125 | ? '0.' + repeat('0', fractDigits - k) + result
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| 126 | : stringSlice(result, 0, k - fractDigits) + '.' + stringSlice(result, k - fractDigits));
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| 127 | } else {
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| 128 | result = sign + result;
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| 129 | } return result;
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| 130 | }
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| 131 | });
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