Subject: Re: Perl gurus: why do we need Scalar::Util?

From: [email-masked] (Randal L. Schwartz)
Date: 10 Jul 2006 06:28:49 -0700

>>>>> "Johannes" == Johannes Schindelin <[email-masked]> writes:

Johannes> please do not let my die dumb: what is this "blessed" thing all about? And 
Johannes> why do we need it in the private-Error.pm??

Ugh.  Just took a peek for the first time at the "next" branch, and I see the
dangerous syntactic-sugar try { } catch { }.  Sorry for not noticing that
earlier.

While that syntax looks like it would make things easier in theory, in
practice it is a source of leak-after-leak because it creates a closure for
the two blocks, and that can easily lead to a circular reference for
long-running tools.  This would be of some concern if someone writes
a mod_perl module or a standalone webserver that doesn't exec itself
to clean up (which it shouldn't need).

So, if there's going to be rewrite, the first part would be to eliminate
the try { } catch { } sugar, and replace it with more traditional
exception catchers.

        eval { };
        if ($@) { ... }

Note that I'm *not* suggesting not to use Error.pm - that's a great
means by which to create hierarchical error classes that stringify nicely
and carry context on the error.  I'm just saying to throw out the
try/catch syntax helper.

Sorry about that.  If it's any consequence, we got it right in Perl 6. :)

-- 
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