Re: [xml-dev] parsing markup with Perl

[Michael Sokolov <msokolov@safaribooksonline.com>]

On 2/8/14 4:08 PM, Arjun Ray wrote:
> But why blame Perl, other than it's the language eveyone loves to
> hate?  (Actually, I thought that would be C++.)
I think it's because regexes (*real* perl regexes, not the pale 
imitations purists refer to as "regular expressions") are so easy to 
use, convenient, and powerful in Perl, unlike other languages (cough, 
Java I'm looking at you).   Python has them too (and Javascript - I 
guess we have to include that now), but re's in these are not 
first-class language constructs the way they are in Perl. Perl 
practically cries out to the programmer "use regexes! I will give you 
magically-scoped variables with all your capture groups. I will drive 
your iteration using /g.  Your program will be super compact!  No more 
RSI!"  Who cares if your code is unreadable and undebuggable.  If you're 
sane, you'll use Perl primarily for one-time text-processing tasks.

I will confess to having built a complex account/subscription management 
system including a web application in 1999 that is still in operation 
today in Perl, that uses regexes to parse its templates, which are in a 
homegrown subset of XML not too far from MicroXML that I stumbled into 
using because I didn't bother to learn what XML syntax really required 
to be parsed.  I would never do this today, but the fact is the system 
actually works fine.  Several other people have had to learn it and 
perform major updates, and this seems to go fairly smoothly.  The 
pseudo-XML templates in particular and their parser (HTML::Macro) have 
never caused any trouble in the least.  They are not used for 
interchange with other systems, so standards are not really particularly 
relevant, and besides they include potentially ill-formed HTML, 
unescaped, something I never could have achieved with a *real* XML 
parser. We fix them when we find them, but in the meantime, no real harm 
is done. So I think there are places for parsing markup with (perl) regexes.

I do agree that Perl lends itself to confusing coding idioms, but at 
least it doesn't have inheritance (not really).  Java programmers I have 
worked with seem to have become so deliriously enamored of formal 
conventions ("patterns," they call them), that they tend to ignore the 
actual problem at hand.  "Ah wait!" they say, "here is an opportunity to 
decorate the interface with a delegation facade!" Every language has its 
pitfalls. C++, yes, very scary traps, but in the end I find that bad 
taste knows no linguistic bounds.  Bad programmers will be bad.

-Mike