Colm programming language released: best parser-writer ever

#1

Post by edwardog » Wed, May 18, 2011, 2:43 PM UTC

Colm programming language released: best parser-writer ever
complang.org

Re: Colm programming language released: best parser-writer ever

#2

Post by bdfh42 » Wed, May 18, 2011, 3:08 PM UTC

Quote "Colm does not yet have any documentation".

Then I would hazard that it is not yet a language as without documentation it has no "grammar". At best it is a patois.

Re: Colm programming language released: best parser-writer ever

#3

Post by thurston » Wed, May 18, 2011, 3:20 PM UTC

bdfh42 wrote: post #2

Quote "Colm does not yet have any documentation". Then I would hazard that it is not yet a language as without documentation it has no "grammar". At best it is a patois.

Grammar: http://svn.complang.org/colm/trunk/colm/lmparse.kl

Re: Colm programming language released: best parser-writer ever

#4

Post by scscsc » Wed, May 18, 2011, 3:26 PM UTC

bdfh42 wrote: post #2

Quote "Colm does not yet have any documentation". Then I would hazard that it is not yet a language as without documentation it has no "grammar". At best it is a patois.

There seems to be a PhD thesis behind, so you should check it for the grammar.

Re: Colm programming language released: best parser-writer ever

#5

Post by wzdd » Wed, May 18, 2011, 3:35 PM UTC

bdfh42 wrote: post #2

Quote "Colm does not yet have any documentation". Then I would hazard that it is not yet a language as without documentation it has no "grammar". At best it is a patois.

TXL, its apparently predecessor, is very well documented (http://www.txl.ca/). TXL is a very interesting approach to parsing and worth reading up on if you're interested in the area (or are waiting for documentation for Colm :)

Re: Colm programming language released: best parser-writer ever

#6

Post by colomon » Wed, May 18, 2011, 3:49 PM UTC

It would be interesting to see someone who understood both this and Perl 6's grammars to do a comparison. Based on Colm's quick description and my rough understanding of Perl 6 grammars, they sound like they are roughly equally powerful. But I admit I'm not sure I understand what "transformation language" means...

Re: Colm programming language released: best parser-writer ever

#7

Post by jws » Wed, May 18, 2011, 3:52 PM UTC

Notice that the DNS example is parsing a binary DNS request, not a text file.

Re: Colm programming language released: best parser-writer ever

#8

Post by thurston » Wed, May 18, 2011, 4:14 PM UTC

colomon wrote: post #6

It would be interesting to see someone who understood both this and Perl 6's grammars to do a comparison. Based on Colm's quick description and my rough understanding of Perl 6 grammars, they sound like they are roughly equally powerful. But I admit I'm not sure I understand what "transformation language" means...

If they are then I don't deserve to be called "Dr. Thurston!"

Re: Colm programming language released: best parser-writer ever

#9

Post by DrCatbox » Wed, May 18, 2011, 4:38 PM UTC

I am more interested in DSNP, how come this project has not received more fame than the infamous Disapora? http://www.complang.org/dsnp/

Re: Colm programming language released: best parser-writer ever

#10

Post by ScottBurson » Wed, May 18, 2011, 4:40 PM UTC

Thurston claims that no previous grammar system supports his three requirements of generalized parsing, grammar-dependent scanning, and context-dependent parsing.

I would argue that Prolog Definite Clause Grammars, which date back to the early 1970s, have all three of these properties. Furthermore, since the context is maintained functionally, by threading additional values through the productions, no "undo actions" are required; Prolog's built-in backtracking is all that's needed.

Of course, the problem with DCGs is performance: they're exponential in the worst case. But I think they deserve mention in a dissertation like this anyway. Also, any backtracking parser risks exponential worst-case performance; it will be interesting to see how Colm avoids this fate (I've only read the first few pages yet).