var global = require('../internals/global');
var call = require('../internals/function-call');
var aCallable = require('../internals/a-callable');
var anObject = require('../internals/an-object');
var tryToString = require('../internals/try-to-string');
var getIteratorMethod = require('../internals/get-iterator-method');

var TypeError = global.TypeError;

module.exports = function (argument, usingIterator) {
  var iteratorMethod = arguments.length < 2 ? getIteratorMethod(argument) : usingIterator;
  if (aCallable(iteratorMethod)) return anObject(call(iteratorMethod, argument));
  throw TypeError(tryToString(argument) + ' is not iterable');
};