梁美英 / programming · Files

'use strict';
var hide     = require('./_hide')
  , redefine = require('./_redefine')
  , fails    = require('./_fails')
  , defined  = require('./_defined')
  , wks      = require('./_wks');

module.exports = function(KEY, length, exec){
  var SYMBOL   = wks(KEY)
    , fns      = exec(defined, SYMBOL, ''[KEY])
    , strfn    = fns[0]
    , rxfn     = fns[1];
  if(fails(function(){
    var O = {};
    O[SYMBOL] = function(){ return 7; };
    return ''[KEY](O) != 7;
  })){
    redefine(String.prototype, KEY, strfn);
    hide(RegExp.prototype, SYMBOL, length == 2
      // 21.2.5.8 RegExp.prototype[@@replace](string, replaceValue)
      // 21.2.5.11 RegExp.prototype[@@split](string, limit)
      ? function(string, arg){ return rxfn.call(string, this, arg); }
      // 21.2.5.6 RegExp.prototype[@@match](string)
      // 21.2.5.9 RegExp.prototype[@@search](string)
      : function(string){ return rxfn.call(string, this); }
    );
  }
};