[plt-scheme] help with parser-tools collection

Thanks for the info, I really appreciate it.

I had thought about doing something like this, but it just seemed SO 
kludgetastic that was I was sure there had to be another way.

Now that I know there *is* no other way... I'll kludge away

Thanks!

On Aug 6, 2004, at 3:59 PM, Scott Owens wrote:

> The lexer doesn't have built-in support for case-insensitivity.
>  The best you can do is:
>  (define-lex-abbrevs (z (: "Z" "z")) (o (: "O" "o")) (n (: "N" "n")) (e
> (: "E" "e")))
>  (lexer
>    ...
>    ((@ z o n e) ...)
>    ...)
>
> which is what I do in the Scheme lexer in
> collects/syntax-color/scheme-lexer.ss
>
> -Scott
>
>
>
> On Aug 6, 2004, at 3:44 PM, Bob McCormick wrote:
>
> >  For list-related administrative tasks:
>  >  http://list.cs.brown.edu/mailman/listinfo/plt-scheme
>  >
>  > I'm having some problems figuring out how to use the Parser-Tools
> > collection, and I'm hoping someone here can help me.   The answer
> > might very well be quite simple, but I'm a newbie to Scheme, and I
>  > haven't had much exposure to other parsers/lexers before either.  
> I'm
> > trying to figure out how to match a case-insensitive string with the
> > lexer.   Does anyone know how to do this?
>  >
>  > More specifically, I'm trying to parse a named.conf file (the
> > configuration file for the Unix name server daemon "bind").  The data
> > I'm trying to parse looks like this:
>  >
>  > zone "web-wide.net"{
>  >         type slave;
>  >         masters {
>  >         67.176.28.44;
>  >         };
>  >         file "web-wide.net";
>  > };
>  >
>  >
>  > And here's what I have so far as a lexer:
>  >
>  > (require (lib "yacc.ss" "parser-tools")
>  >          (lib "lex.ss" "parser-tools")
>  >          (lib "readerr.ss" "syntax"))
>  >
>  > (define-tokens value-tokens (STRING))
>  > (define-empty-tokens stanza-tokens (newline ZONE OB CB EOF QUOTE))
>  >
>  > (define-lex-abbrevs
>  >  (lower-letter (- "a" "z"))
>  >
>  >  (upper-letter (- #\A #\Z))
>  >
>  >  ;; (- 0 9) would not work because the lexer does not understand
> > numbers.  (- #\0 #\9) is ok too.
>  >  (digit (- "0" "9")))
>  >
>  > (define zonel
> >   (lexer
>  >    ((eof) 'EOF)
>  >    (#\newline 'newline)
>  >    ((: #\tab #\space) (zonel input-port))
>  >    ("{" 'OB)
>  >    ("}" 'CB)
>  >    ("\"" 'QUOTE)
>  >    ("zone" 'ZONE)
>  >    ((+ (: lower-letter upper-letter)) (token-STRING (string->symbol
>  > lexeme)))))
>  >
>  >
>  > This will match the string "zone" in lowercase, but the named.conf
> > file is case-insensitive, so I need to also be able to match "ZONE",
> > "zOne", etc.
>  >
>  > Does anyone have some guidance on how to go about doing this?