May 28, 2012

Perl Core Syntax Wishlist: Class support

I would like to see the class keyword become part of Perl, but unlike some I don't want it simply because it's nicer syntax. I'd like it to behave differently from package. I'd basically like to see this I'm sure smarter people than I could think of a few more things that might be nice to have by default in all classes. I would like to note that method signatures is not that big of a deal to me, unless of course you want to give me named variables in the signature besides just auto shifting off self, e.g. method foo ( $bar ) { return $self->{foo} if $bar }

May 21, 2012

Better Exceptions with Exception::Base

So I've done some complaining and explaining about what I'd like to see in regards to Exceptions in Perl. I Mostly explained what I wanted for catching Exceptions, and a little on throwing Exception objects, but not really how those objects should behave. I've looked at and tried various exception modules, including croak, confess, and Throwable. I basically spent time one day reading the manuals of most of the exception objects on CPAN. Most of them didn't allow me to easily for the exceptions I needed (meaning they required more work than I thought I should do for one or two exceptions ). Among these modules I found Exception::Base, which appears to do everything I need (though I still wish for something like it in core, with shinier syntax). Of course wee need to be able to throw simple Exceptions, preferably ones that can stringify, and are easily matched in a switch or if statement. Exception::Base can do all of that, and it even boolifies to true. A really big thing I wanted was a class I could easily add attributes to without writing a whole new package/pm and subclassing it there. I wanted this because I really wanted to be able to have 2 kinds of messages, one for programmers, and one for users, but truthfully I only had one class where I needed this flexibility (at the time). It is also occasionally useful to have attributes that describe something, e.g. would be really useful in moose attribute exceptions, to be able to have an object where you could catch the exception and get the attribute name without parsing. Fortunately Exception::Base can do this too. You'll notice if you run this script that in the warn, both usermsg and logmsg are printed because they are both string_attributes. You'll also notice that attr isn't printed at all, but that we can look at it directly to make other decisions. Exception::Base has other features such as setting the verbosity so you can go from a croak level message to a full stacktrace. It also allows you to ignore_packages so that the exception does not appear to be thrown from that package. This is similar to @CARP_NOT.

May 14, 2012

Perl Core Syntax Wishlist: die should die

I hate die it is, in my humble opinion, one of the worst parts of perl. I really wish it would be deprecated, and removed, or at least replaced with something that would tell you were the code that was die-ing was being called. Replace its implementation with that of Carp's croak or confess and I'd be happy. Better yet, let's just get real exception support and deprecate die (even if that's never removed deprecation just make that real big on its pod). If you're using die please stop and use Carp, anyone using your module will thank (and by thank I mean not curse) you later.

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, 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: 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.