es6.number.constructor.js
2.56 KB
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
'use strict';
var $ = require('./$')
, global = require('./$.global')
, has = require('./$.has')
, cof = require('./$.cof')
, toPrimitive = require('./$.to-primitive')
, fails = require('./$.fails')
, $trim = require('./$.string-trim').trim
, NUMBER = 'Number'
, $Number = global[NUMBER]
, Base = $Number
, proto = $Number.prototype
// Opera ~12 has broken Object#toString
, BROKEN_COF = cof($.create(proto)) == NUMBER
, TRIM = 'trim' in String.prototype;
// 7.1.3 ToNumber(argument)
var toNumber = function(argument){
var it = toPrimitive(argument, false);
if(typeof it == 'string' && it.length > 2){
it = TRIM ? it.trim() : $trim(it, 3);
var first = it.charCodeAt(0)
, third, radix, maxCode;
if(first === 43 || first === 45){
third = it.charCodeAt(2);
if(third === 88 || third === 120)return NaN; // Number('+0x1') should be NaN, old V8 fix
} else if(first === 48){
switch(it.charCodeAt(1)){
case 66 : case 98 : radix = 2; maxCode = 49; break; // fast equal /^0b[01]+$/i
case 79 : case 111 : radix = 8; maxCode = 55; break; // fast equal /^0o[0-7]+$/i
default : return +it;
}
for(var digits = it.slice(2), i = 0, l = digits.length, code; i < l; i++){
code = digits.charCodeAt(i);
// parseInt parses a string to a first unavailable symbol
// but ToNumber should return NaN if a string contains unavailable symbols
if(code < 48 || code > maxCode)return NaN;
} return parseInt(digits, radix);
}
} return +it;
};
if(!$Number(' 0o1') || !$Number('0b1') || $Number('+0x1')){
$Number = function Number(value){
var it = arguments.length < 1 ? 0 : value
, that = this;
return that instanceof $Number
// check on 1..constructor(foo) case
&& (BROKEN_COF ? fails(function(){ proto.valueOf.call(that); }) : cof(that) != NUMBER)
? new Base(toNumber(it)) : toNumber(it);
};
$.each.call(require('./$.descriptors') ? $.getNames(Base) : (
// ES3:
'MAX_VALUE,MIN_VALUE,NaN,NEGATIVE_INFINITY,POSITIVE_INFINITY,' +
// ES6 (in case, if modules with ES6 Number statics required before):
'EPSILON,isFinite,isInteger,isNaN,isSafeInteger,MAX_SAFE_INTEGER,' +
'MIN_SAFE_INTEGER,parseFloat,parseInt,isInteger'
).split(','), function(key){
if(has(Base, key) && !has($Number, key)){
$.setDesc($Number, key, $.getDesc(Base, key));
}
});
$Number.prototype = proto;
proto.constructor = $Number;
require('./$.redefine')(global, NUMBER, $Number);
}