Re: [Ocaml-lib-devel] Re: regeps (repost)

[skaller <sk...@us...>]

On Sat, 2004-09-11 at 04:50, Jesse Guardiani wrote:
> Richard Jones wrote:
> 
> > (Repost: original was apparently tagged as sp*m).
> > 
> > Not really sure I understand it from a user's point of view.
> > 
> > For me what really matters is that I could write something like:
> > 
> >   if string =~ /(a+)(b*)/ then ...
> > 
> > The regular expression (Perl-compatible, please!) ought to be compiled
> > and checked at compile time, and the compiler should handle caching
> > compiled expressions containing variables.
> 
> That would certainly be nice.

Felix actually uses a syntax like this:

open Lexer;

regexp digit = ["0123456789"];
regexp digits3 = digit digit digit;
regexp digits4 =  digits3 digit;

regexp area_code = digits3 | "(" digits3 ")";
regexp exchange = digits3;

regexp phone = area_code " " exchange (" " | "-") digits4;

reglex start to finish with
  | phone => ....
  | _ => ""
endmatch

which is an excerpt from the Bagley Shootout test.

-- 
John Skaller, mailto:sk...@us...
voice: 061-2-9660-0850, 
snail: PO BOX 401 Glebe NSW 2037 Australia
Checkout the Felix programming language http://felix.sf.net