es6.number.to-fixed.js
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'use strict';
var $export = require('./_export');
var toInteger = require('./_to-integer');
var aNumberValue = require('./_a-number-value');
var repeat = require('./_string-repeat');
var $toFixed = 1.0.toFixed;
var floor = Math.floor;
var data = [0, 0, 0, 0, 0, 0];
var ERROR = 'Number.toFixed: incorrect invocation!';
var ZERO = '0';
var multiply = function (n, c) {
var i = -1;
var c2 = c;
while (++i < 6) {
c2 += n * data[i];
data[i] = c2 % 1e7;
c2 = floor(c2 / 1e7);
}
};
var divide = function (n) {
var i = 6;
var c = 0;
while (--i >= 0) {
c += data[i];
data[i] = floor(c / n);
c = (c % n) * 1e7;
}
};
var numToString = function () {
var i = 6;
var s = '';
while (--i >= 0) {
if (s !== '' || i === 0 || data[i] !== 0) {
var t = String(data[i]);
s = s === '' ? t : s + repeat.call(ZERO, 7 - t.length) + t;
}
} return s;
};
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;
};
$export($export.P + $export.F * (!!$toFixed && (
0.00008.toFixed(3) !== '0.000' ||
0.9.toFixed(0) !== '1' ||
1.255.toFixed(2) !== '1.25' ||
1000000000000000128.0.toFixed(0) !== '1000000000000000128'
) || !require('./_fails')(function () {
// V8 ~ Android 4.3-
$toFixed.call({});
})), 'Number', {
toFixed: function toFixed(fractionDigits) {
var x = aNumberValue(this, ERROR);
var f = toInteger(fractionDigits);
var s = '';
var m = ZERO;
var e, z, j, k;
if (f < 0 || f > 20) throw RangeError(ERROR);
// eslint-disable-next-line no-self-compare
if (x != x) return 'NaN';
if (x <= -1e21 || x >= 1e21) return String(x);
if (x < 0) {
s = '-';
x = -x;
}
if (x > 1e-21) {
e = log(x * pow(2, 69, 1)) - 69;
z = e < 0 ? x * pow(2, -e, 1) : x / pow(2, e, 1);
z *= 0x10000000000000;
e = 52 - e;
if (e > 0) {
multiply(0, z);
j = f;
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);
m = numToString();
} else {
multiply(0, z);
multiply(1 << -e, 0);
m = numToString() + repeat.call(ZERO, f);
}
}
if (f > 0) {
k = m.length;
m = s + (k <= f ? '0.' + repeat.call(ZERO, f - k) + m : m.slice(0, k - f) + '.' + m.slice(k - f));
} else {
m = s + m;
} return m;
}
});