Haxe: Null object pattern for iterables -

i'd implement null object design pattern iterable class. example if internal array isn't initialized, wrapper class anyway returns empty iterator doesn't break main logic:

public function iterator():iterator<t> {   // ...of cause doesn't work, because iterator typedef not class   return mlist != null ? mlist.iterator() : new iterator<t>(); }  var mlist:array<t>; 

should instantiate static empty dummy array desired type of items or else implements iterator interface contains nothing? or may there more straight solution?

you check @ forehand in object class itself, adding kind of isempty function:

public function isempty():bool {   return mlist == null || mlist.length == 0; } 

then use this:

if(!iter.isempty()) {   for(i in iter) {     trace(i);   } } 

example: http://try.haxe.org/#8719e

or

you use dummy iterator this:

class nulliterator  {     public inline function hasnext() return false;     public inline function next() return null;     public inline function new() {} } 

.. , use

public function iterator():iterator<t> {   return mlist != null ? mlist.iterator() : new nulliterator(); } 

example: http://try.haxe.org/#b2d7e

if think behavior should changed, raise issue on github. https://github.com/haxefoundation/haxe/issues