es6.number.constructor.js 2.9 KB

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  1. 'use strict';
  2. var global = require('./_global')
  3. , has = require('./_has')
  4. , cof = require('./_cof')
  5. , inheritIfRequired = require('./_inherit-if-required')
  6. , toPrimitive = require('./_to-primitive')
  7. , fails = require('./_fails')
  8. , gOPN = require('./_object-gopn').f
  9. , gOPD = require('./_object-gopd').f
  10. , dP = require('./_object-dp').f
  11. , $trim = require('./_string-trim').trim
  12. , NUMBER = 'Number'
  13. , $Number = global[NUMBER]
  14. , Base = $Number
  15. , proto = $Number.prototype
  16. // Opera ~12 has broken Object#toString
  17. , BROKEN_COF = cof(require('./_object-create')(proto)) == NUMBER
  18. , TRIM = 'trim' in String.prototype;
  19. // 7.1.3 ToNumber(argument)
  20. var toNumber = function(argument){
  21. var it = toPrimitive(argument, false);
  22. if(typeof it == 'string' && it.length > 2){
  23. it = TRIM ? it.trim() : $trim(it, 3);
  24. var first = it.charCodeAt(0)
  25. , third, radix, maxCode;
  26. if(first === 43 || first === 45){
  27. third = it.charCodeAt(2);
  28. if(third === 88 || third === 120)return NaN; // Number('+0x1') should be NaN, old V8 fix
  29. } else if(first === 48){
  30. switch(it.charCodeAt(1)){
  31. case 66 : case 98 : radix = 2; maxCode = 49; break; // fast equal /^0b[01]+$/i
  32. case 79 : case 111 : radix = 8; maxCode = 55; break; // fast equal /^0o[0-7]+$/i
  33. default : return +it;
  34. }
  35. for(var digits = it.slice(2), i = 0, l = digits.length, code; i < l; i++){
  36. code = digits.charCodeAt(i);
  37. // parseInt parses a string to a first unavailable symbol
  38. // but ToNumber should return NaN if a string contains unavailable symbols
  39. if(code < 48 || code > maxCode)return NaN;
  40. } return parseInt(digits, radix);
  41. }
  42. } return +it;
  43. };
  44. if(!$Number(' 0o1') || !$Number('0b1') || $Number('+0x1')){
  45. $Number = function Number(value){
  46. var it = arguments.length < 1 ? 0 : value
  47. , that = this;
  48. return that instanceof $Number
  49. // check on 1..constructor(foo) case
  50. && (BROKEN_COF ? fails(function(){ proto.valueOf.call(that); }) : cof(that) != NUMBER)
  51. ? inheritIfRequired(new Base(toNumber(it)), that, $Number) : toNumber(it);
  52. };
  53. for(var keys = require('./_descriptors') ? gOPN(Base) : (
  54. // ES3:
  55. 'MAX_VALUE,MIN_VALUE,NaN,NEGATIVE_INFINITY,POSITIVE_INFINITY,' +
  56. // ES6 (in case, if modules with ES6 Number statics required before):
  57. 'EPSILON,isFinite,isInteger,isNaN,isSafeInteger,MAX_SAFE_INTEGER,' +
  58. 'MIN_SAFE_INTEGER,parseFloat,parseInt,isInteger'
  59. ).split(','), j = 0, key; keys.length > j; j++){
  60. if(has(Base, key = keys[j]) && !has($Number, key)){
  61. dP($Number, key, gOPD(Base, key));
  62. }
  63. }
  64. $Number.prototype = proto;
  65. proto.constructor = $Number;
  66. require('./_redefine')(global, NUMBER, $Number);
  67. }