Homework/Fakogram REACT project/node_modules/core-js/modules/$.array-methods.js

// 0 -> Array#forEach
// 1 -> Array#map
// 2 -> Array#filter
// 3 -> Array#some
// 4 -> Array#every
// 5 -> Array#find
// 6 -> Array#findIndex
var ctx      = require('./$.ctx')
  , IObject  = require('./$.iobject')
  , toObject = require('./$.to-object')
  , toLength = require('./$.to-length')
  , asc      = require('./$.array-species-create');
module.exports = function(TYPE){
  var IS_MAP        = TYPE == 1
    , IS_FILTER     = TYPE == 2
    , IS_SOME       = TYPE == 3
    , IS_EVERY      = TYPE == 4
    , IS_FIND_INDEX = TYPE == 6
    , NO_HOLES      = TYPE == 5 || IS_FIND_INDEX;
  return function($this, callbackfn, that){
    var O      = toObject($this)
      , self   = IObject(O)
      , f      = ctx(callbackfn, that, 3)
      , length = toLength(self.length)
      , index  = 0
      , result = IS_MAP ? asc($this, length) : IS_FILTER ? asc($this, 0) : undefined
      , val, res;
    for(;length > index; index++)if(NO_HOLES || index in self){
      val = self[index];
      res = f(val, index, O);
      if(TYPE){
        if(IS_MAP)result[index] = res;            // map
        else if(res)switch(TYPE){
          case 3: return true;                    // some
          case 5: return val;                     // find
          case 6: return index;                   // findIndex
          case 2: result.push(val);               // filter
        } else if(IS_EVERY)return false;          // every
      }
    }
    return IS_FIND_INDEX ? -1 : IS_SOME || IS_EVERY ? IS_EVERY : result;
  };
};