[haXe] blocks and yield?

[blackdog]

On Fri, 06 Apr 2007 18:40:49 +0200
Nicolas Cannasse <ncannasse at motion-twin.com> wrote:

> > hi list
> > 
> > It'd be nice to have the rubyish block and yield construct in haxe,
> > it's just a bit of 'syntactic sugar' as it seems to me all the
> > requisite plumbing exists.
> > 
> > obj.method() { x -> block }
> 
> For blocks, there is a problem of syntax, since using { } will lead to
> major conflicts.
> 

i'm not stuck on {} :), how about a double {{ .... }} ?

> For "yield", this need appropriate VM support which is not available
> either in Flash or JS.
>

yeild is really just calling a closure, no? I guess i'm thinking much
more of the groovy implementation which is much closer to haxe than
ruby is

java doesn't have a yield in the vm either (as far as i know), but
groovy does it like this

public method(int x,Closure c)  {
// snip
 	c.call(myparam);
// snip
}

called with

obj.method(1) { p ->
	println p
}

OR

obj.method(1,{p-> println p})

the block/closure is tacked onto the end of the param list.

in haxe within the called method it could know it's dealing with a
pointer to a function in the same way, and have an anonymous function
passed as the the last parameter, 

in haxe

public function generate(x:Int,f:Dynamic->Void) {
	f(myparam);
}


called with

obj.generate() {{ x ->
	trace(x)
}}



the groovy way is not intrinsic to the VM it is syntactic sugar on the
calling side, and works very well. 

if you're interested here's some groovy info

http://groovy.codehaus.org/Closures

  
> Nicolas
>