PROPOSAL: Enhanced for each loop iteration control

[Stefan Schulz]

I don't particularly like the enriched for each iteration control. While 
the J5-for-each loop only adds as syntactic sugar for convenient 
looping, iteration control adds overhead to the loop by creating two 
instances per for-each, counting the index, etc. Hence, as a developer 
in most cases one would be better off with doing the iterator stuff 
oneself.

Frankly, I cannot see a great advantage of:
   for (Foo foo : fooList : it) {
     ...
   }
saving two lines of code over:
   Iterator<Foo> it = fooList.iterator();
   while (it.hasNext()) {
     Foo foo = it.next();
     ...
   }
by adding two wrappers and stuff to the code in the background.

The idea to employ a label to access the iterator I find even worse. A 
label does not relate to anything at runtime but a location in code.

Stefan

Marek Kozieł schrieb:
> As you can see i was thinking about it for while:
> http://mail.openjdk.java.net/pipermail/coin-dev/2009-March/001105.html
> 
> And i found few problems.
> New iterator Interface is wrong path, because people will be not able
> to use it with their iterators.
> 
> 
> So from your proposal I would remove Interface-s and link iterator
> through label,
> label type is return type of .iterator() method.
> 
> 
> like:
> 
> ArrayList<String> some ....;
> ...
> i: for (Strign s:some){
>     if (  (s==null) || (s.equals("bad")) )) i.remove();
>     ...
>     i.next(); // compile time error ?
>     i.hasNext(); // OK
>     Iterator<String> s = i; // error i is not variable (it just allow
> to access it;)
> }
> 
> String[] array ...;
> i: for (String s:array){
>     i.getIndex;//?
> }
> 
> 
> 
> --
> Pozdrowionka. / Regards.
> Lasu aka Marek Kozieł
> 
> http://lasu2string.blogspot.com/
>