[OT] Should exist / does exist?
andy at hexten.net
Thu Dec 7 00:54:16 GMT 2006
On 7 Dec 2006, at 00:12, Joel Bernstein wrote:
> I've got code working which can do the earlier stuff you mentioned,
> except specific loop labels. I'm not so sure it couldn't do what
> asking. I'll post it to the list if you want a look, it's basically
> using a lot of sugar around eval/die though, which as I understand it
> you have already got working... I have subs Next/Last/Redo which
> construct Iterator::Error objects which are trapped out of $@ and
> on appropriately.
Yes, that's the way I'm gravitating. I might play with a module the
exports methods called next, last and redo into the caller's
namespace and has them construct unambiguous loop exit exceptions as
you describe. I can nearly convince that plus helpers to assist in
the classification of the exit exception might be worth having.
I guess the same module could expose optional sugar that'd use
B::Disassembler / B::Assembler or B::Deparse to rewrite the closure
although I'm not sure it's really worth it.
> My worry is that to add the kind of tree-walking
> behaviour you outline above you would have to bolt the sugar in so
> to the algorithm that you would end up with code that was less clear
> overall than when you started out...
Quite possibly :)
Although I think that in the tree walking example I posted it'd be
easy enough - and useful - to bail out of the recursion if the loop
closure called $tree_walker->last;
Andy Armstrong, hexten.net
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