From: "Hal Fulton (Manning)" <hafu@...>
Date: 2003-04-17T06:42:05+09:00
Subject: Re: regular expressions

----- Original Message ----- 
From: "Arthur Chance" <{spamtrap}@qeng-ho.org>
Newsgroups: comp.lang.ruby
To: "ruby-talk ML" <ruby-talk@ruby-lang.org>
Sent: Wednesday, April 16, 2003 1:14 PM
Subject: Re: regular expressions


> > First of all, it does my heart good to know that I am not 
> > actually the oldest person on this list. When you were
> > programming in SNOBOL, I was barely in sixth grade, and 
> > the only computers I knew of were in _Star Trek_ reruns.
> 
> Excuse me while I go and quietly crumble in the corner. :-)
> 
> As you get older either the memory goes or the mental arithmetic
> abilities, but I can't remember which. However, a recalculation shows
> me that it was only a mere 27-28 years ago that I started using
> Snobol. Even with that correction it was still back when I had far
> more hair and far less waist. :-)

Ha... don't take it personally. I'm constantly reminded that
some of these people are current undergraduates, and were born
in 1983 or so. In the perspective of many such people, I am 
nothing but a dinosaur, I who learned Pascal in 1980. No worries. 
We've all been young, and we will all all either grow old or 
die young. Eternity is very democratic.

[snippage]
 
> Anyway, I hadn't seen Rockit before you mentioned it, so this is an
> off the top of the head response. I have seriously used lexical and
> parser generators as well as hand writing lexers and parsers over the
> years (part of my career has been in academic CS, part designing and
> implementing proprietary languages for industry including one (Magik)
> that's remarkably like Ruby in feel. Matz and I obviously absorbed the
> same influences.)
> 
> My general feeling is that regexps or similar ideas like Snobol
> patterns are at a different level from parsing. Of course, the fact
> that Rockit (like a few other parser generators) generates both lexer
> and scanner from the same input rather blurs the distinction, but I
> tend to think lexing is like brick laying and parsing is like
> architecture - you generally wouldn't want one job done by the
> practitioner of the other.

Well, frankly I can't remember how I reached the
conclusion that Rockit was the superior to what
I had conceived. Search the archives if you wish,
it's in there.  :)

[snip comments on parsers]

I don't know enough about parsers to fully grasp what
you're saying. But it sounds OK to me. :)

Hal