Re: getting the argument list of a procedure

[David Nalesnik]

Hi Orm,

On Wed, Mar 4, 2015 at 3:54 PM, Orm Finnendahl <address@hidden> wrote:

Dear David,

Am Mittwoch, den 04. März 2015 um 15:35:46 Uhr (-0600) schrieb David Nalesnik:
>
> I would like to be able to return the argument list of a Scheme function,
> say as a list of symbols.

I'm not sure I understand what exactly you're looking for. In scheme,
you can assign a name to all arguments of a function and refer to it
in the function body if you use dot notation. All arguments are
accessible within the body as a list referred to by the symbol after
the dot:

(define (return-args . args)
        args)


(return-args 1 2 3 'blah 'foo "blub")

-> (1 2 3 blah foo "blub")

Does that answer your question?

Sorry for being opaque! 

What I'm trying to do (ultimately) is come up with a way to automatically document the large number of public Scheme functions (like grob::has interface or grob::name) in a similar format as used for the functions here: http://lilypond.org/doc/v2.18/Documentation/internals/scheme-functions

Some of the information is easily accessible: procedure-name gives us the name of the function, procedure-documentation gives the doc string.  What I'm missing is a good way to get at the names of the arguments.

Now I suppose I could manipulate strings.  Something like the following (just a proof-of-concept  I just hacked together):

#(use-modules (ice-9 regex))

#(define (find-args proc)

   (let* ((str (format #f "~a" proc))

          (s (string-match "\\(.*\\)" str)))

     (match:substring s)))

#(display (find-args grob-interpret-markup))

==> (grob text)

However, this feels a little hacky to me, and I'm hoping that there's some better technique available to get at the names assigned to the arguments.

--David