On Wed, Jun 08, 2005 at 12:20:57PM -0700, Larry Wall wrote:
>  : I'm not sure how this selection mechanism is meant to be used.
>  
>  The skip is meant to be applied after filtration.  Don't filter out
>  things you want to see later, in other words.

Okay, caller done as r4555. Without :label for now, because we don't
have that yet.

>  : - AES does not enumerate the complete member set. We can use that now :)
>  
>  Um.  That's something I wouldn't mind delegating to whoever is slogging
>  it out on the ground.

That's fine for caller, but half the examples for want imply things that
aren't available in Pugs' exisitng want yet (count, rw), and I think they
might not be straightforward to add. If there are other things come to
mind they'll probably be easier to add all at once.

[.sub ->  .subname ; .sub returns coderef]
>  That's the direction we're going with &?SUB and $?SUBNAME, so I don't
>  see why it couldn't apply here too.
 
Done.

>  It would be nice if the interfaces were similar where they try to do
>  similar things.
>  
>  But then, it might be nice to copy over the :nth($n) interface from
>  pattern matching too, somehow or other.  Right now our selectors don't
>  have a way to generalize that.  You almost want to be able to say
>  something like caller(3rd(Sub)), which causes ~~ to match Sub, but
>  only on the third thing that could be construed as a Sub, presuming
>  ~~ is treating the other argument as some kind of iterator.  But up
>  till now we've been treating such iterators as external to ~~, with
>  the args matched one at a time.  One could imagine seeing things like:
>  
>      given =$IN {
>  	when 1st(/foo/)  {...}
>  	when 2nd(/bar/)  {...}
>  	when 3rd(/baz/)  {...}
>      }
>  
>  but the semantics of such a construct are more than somewhat problematic.

Is caller so time-critical that saying 3rd(caller(Sub)) is too bad?

FWIW, this is how I interpreted caller(Sub, :skip<2> ), as "the third
sub". And unless I'm wrong, caller(Block, :skip<2> , :label<moose>) would
mean, "once you get to the third Block, look on for one labeled "moose".
So we don't have a way to skip three methods and then look for a labeled
block, but if the user really wants that, let them grovel over a
complete call chain themselves.

-- 
Gaal Yahas <gaal@[...].org> 
http://gaal.livejournal.com/