xenoterracide: Perl Core Syntax Wishlist: an Exception Stack

May 7, 2012

Perl Core Syntax Wishlist: an Exception Stack

I have come to wish many things were part of Perl syntax that are not, and no using external modules is not enough for me. I think it's time Perl got the features as part of the language itself (and yes I suppose I could settle for feature.pm, and no I'm probably not going to write them myself, I'm not smart enough yet). The first of these is a proper exception stack. I want to be able to write:

use 5.018; use warnings; sub foo { throw Exception->new( 'message' ); } try { foo(); } catch ( 'Exception' ) { say "$_"; # object stringifies } catch ( 'Exception::Other' ) { say $_->message #also has an accessor } finally { ... }

I think we need throw, try, catch, and finally keywords. And no I don't think it makes sense to have Object->throw. In fact I think this Original Perl 6 Syntax Proposal reads like just what we need in Perl 5. Unfortunately I think this is what we are getting in Perl 6, which IMO is not as nice.

2 comments:

MySZMay 28, 2012 at 4:35 AM
It's nearly the same what my company needs ;) And i wrote something what allow to work in this way.

You just need few classes of exceptions:
Exception
RuntimeException

and so on.

Next, alias for die/croak (*throw = \&croak - this is our way).

And next, I made a package (based on Try::Tiny): Try::Tiny::SmartCatch.
It has a little strange syntax, but its power forgive this (i think ;) ).
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Caleb CushingMay 28, 2012 at 3:38 PM
we should not, stop adding syntax to Perl because cpan modules are able to do it.
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