Lambda the Ultimate

inactiveTopic Just wondering (strings)
started 12/4/2002; 4:56:21 AM - last post 12/5/2002; 10:11:20 AM
Ehud Lamm - Just wondering (strings)  blueArrow
12/4/2002; 4:56:21 AM (reads: 573, responses: 9)
How come discussions of string processing languages don't mention perl? Aren't regular experssions, and extended regular expressions important approaches for string manipulation?

Isaac Gouy - Re: Just wondering (strings)  blueArrow
12/4/2002; 9:40:49 AM (reads: 591, responses: 1)
Isn't that discussion more about languages that influenced Icon? I don't imagine they were specifically ignoring Perl - they don't mention Awk or Tcl either.

Given that Perl style Regex is available within C# and J2SE, are we back to languages vs. libraries?

Ehud Lamm - Re: Just wondering (strings)  blueArrow
12/4/2002; 12:36:56 PM (reads: 631, responses: 0)
I am not sure. Icon and Snobol4 both have specific language features helpful for string processing.

Noel Welsh - Re: Just wondering (strings)  blueArrow
12/5/2002; 4:50:11 AM (reads: 554, responses: 1)
I guess its because the paper is from 1993, which is before the great web explosion that bought Perl to many people's attention.

Though I don't know much of either languages I believe Icon has more language specific features that make it easier to process strings. Specifically its evaluation order makes it quite easy to write lexers and parsers. Perl has many nice syntax hacks like as-strings but nothing at this deep a level.

Ehud Lamm - Re: Just wondering (strings)  blueArrow
12/5/2002; 5:00:14 AM (reads: 595, responses: 0)
Well, Perl 6 is going to add several cool features.

Noel Welsh - Re: Just wondering (strings)  blueArrow
12/5/2002; 5:24:01 AM (reads: 555, responses: 3)
Really? You're not referrring to a reinvention of 1970s parser technology that the rest of the world calls recursive descent parsing but the Perl community calls regular expressions (as featured on LtU)?

Frank Atanassow - Re: Just wondering (strings)  blueArrow
12/5/2002; 10:11:20 AM (reads: 554, responses: 0)
You may find this hard to believe, but I swear that was not me posting under Noel's account. :)

Ehud Lamm - Re: Just wondering (strings)  blueArrow
12/5/2002; 11:21:36 AM (reads: 575, responses: 2)
But doesn't putting this in a language qualify as disruptive technology?!

Noel Welsh - Re: Just wondering (strings)  blueArrow
12/6/2002; 6:23:53 AM (reads: 579, responses: 1)
My tone was a bit inflammatory, for which I apologise. I do think there is value (lots of value indeed) in intergrating parsing into a language. I just think just about everything Perl does is butt-ugly, and it really annoys me that they don't pay their respects to those who came before. E.g.:

Larry could have taken the same approach with regular expressions. He could have tweaked some of the syntax, added new ... constructs, cleaned up the rougher edges, and moved on.

Fortunately, however, he's taking a much broader view of Perl's future than powerful as Perl 5 regexes are, they are not nearly powerful enough. Modern text manipulation is predominantly about processing structured, hierarchical text. And that's just plain painful with regular expressions. The advent of modules like Parse::Yapp and Parse::RecDescent reflects the community's widespread need for more sophisticated parsing mechanisms. Mechanisms that should be native to Perl.

As if we haven't know that FSMs are strictly less expressive than push-down automata since, what, 1965? As if Larry Wall was some language designer god creating these amazing constructs no-one has ever thought of before. Sheesh.

The original post on the topic is I was more civil there ;-)

BTW, I'm honoured to be mistaken for Frank!

Ehud Lamm - Re: Just wondering (strings)  blueArrow
12/6/2002; 6:52:58 AM (reads: 614, responses: 0)
BTW, I'm honoured to be mistaken for Frank! Yeah, I was going for that myself...

Anyway, I agree that there are many papers that discuss how Perl fits in with the rich history of parsing, and string processing. That was my original point!

Indeed, I am not aware of any such paper (but maybe I am just being forgetful)