From: Robert Klemme <bob.news@...>
Date: 2005-09-07T02:06:29+09:00
Subject: Re: ruby style blocks in java

Martin Ankerl <martin.ankerl@gmail.com> wrote:
> Is there a nice way to implement Ruby-style blocks in Java? I have to
> code in Java and I really miss this feature. This is the best thing I
> came up with, but it is soooo verbose (untested, just from my head):
>
>
> interface Block {
>   public Object yield(Object o);
> }
>
> class Array {
>   public void do(Block b) {
>     // do something here
>     while (it.hasNext()) {
>       Object o = it.next();
>       block.yield(o);
>    }
> }
>
> class Someth
>   public void doSomething() {
>     Array a = new Array();
>     // do something before
>     a.do(new Block() {
>       public void yield(Object o) {
>         // here is the yield code
>       }
>     }
>     // do something afterwards
>   }
> }

That's probably as close as it can get.  If you want methods from Enumerable 
you probably end up writing static methods that receive an Iterator or a 
Collection and a Block.  Not very elegant though.

You can also use Groovy - which is quite Ruby like and Java under the hoods. 
Unfortunately it's significantly slower that pure Java - and maybe also as 
Ruby.

Kind regards

    robert