'use strict'; | |
var $export = require('./_export') | |
, anInstance = require('./_an-instance') | |
, toInteger = require('./_to-integer') | |
, aNumberValue = require('./_a-number-value') | |
, repeat = require('./_string-repeat') | |
, $toFixed = 1..toFixed | |
, floor = Math.floor | |
, data = [0, 0, 0, 0, 0, 0] | |
, ERROR = 'Number.toFixed: incorrect invocation!' | |
, ZERO = '0'; | |
var multiply = function(n, c){ | |
var i = -1 | |
, c2 = c; | |
while(++i < 6){ | |
c2 += n * data[i]; | |
data[i] = c2 % 1e7; | |
c2 = floor(c2 / 1e7); | |
} | |
}; | |
var divide = function(n){ | |
var i = 6 | |
, c = 0; | |
while(--i >= 0){ | |
c += data[i]; | |
data[i] = floor(c / n); | |
c = (c % n) * 1e7; | |
} | |
}; | |
var numToString = function(){ | |
var i = 6 | |
, 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 | |
, 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..toFixed(0) !== '1000000000000000128' | |
) || !require('./_fails')(function(){ | |
// V8 ~ Android 4.3- | |
$toFixed.call({}); | |
})), 'Number', { | |
toFixed: function toFixed(fractionDigits){ | |
var x = aNumberValue(this, ERROR) | |
, f = toInteger(fractionDigits) | |
, s = '' | |
, m = ZERO | |
, e, z, j, k; | |
if(f < 0 || f > 20)throw RangeError(ERROR); | |
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; | |
} | |
}); |