[racket] Literate programming: help with @chunks

That should work. When I require that file I get this:

  compile: unbound identifier in module in: define-empty-tokens

and then when I fix it like this:

@chunk[<*>
       (require parser-tools/lex)
       (define-empty-tokens mt-token-group (<empty-tokens>))]

things seem to work fine.

Robby

On Fri, May 20, 2011 at 6:45 AM, Tim Brown <tim.brown at cityc.co.uk> wrote:
> Hello,
>
> I'm writing a literate program which includes a lexer/parser.
> I am trying to build up the lexer a token at a time...
>
> ---------
> #lang scribble/lp
> @section{newlines}
> A newline is at the end of a line... in fact we'll consume all newlines,
> since we don't care how many there are.
> @chunk[<empty-tokens> new-line]
> @chunk[<lex-rules> ((:+ (:or #\newline #\return)) (token-new-line))]
>
> @section{End of file}
> The parser would like to know when I've run out of file...
> @chunk[<empty-tokens> end-of-file]
> @chunk[<lex-rules> ((eof) (token-end-of-file))]
>
>
> @chunk[<*>
> (define-empty-tokens mt-token-group (<empty-tokens>))
> ]
> -------------
>
> Upon requiring this module; I get:
>  "lex-lp.rkt:5:22: compile: unbound identifier in module in: new-line"
>
> Should I be able to do this? Should the LP code replace <*> with:
> (define-empty-tokens mt-token-group (new-line end-of-file))
> and then evaluate it?
>
> Or am I doing something horribly wrong (again).
>
> Regards,
>
> Tim
>
> --
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