Re: unhandled constant?

[Han-Wen Nienhuys <hanwenn@gmail.com>]

[guile1.8]$ grep -ir define-syntax-rule .

(empty)

I  need something that works in GUILE 1.8 too.

this is what I got from David Kastrup:

>Got any comments about macros being sooo yesterday compared to syntax
forms?  Syntax forms actually don't work in LilyPond: there was an
incompatibility because the 1.8 implementation will balk if some symbol
used in syntax forms already has a definition, and we have that.  I
forgot the exact symbol at fault.  I think it was some music function
name.

Would there be a way that we can use our source code unchanged with GUILE 2.2?

Can you explain why I get this error message?

On Wed, Jan 29, 2020 at 4:06 PM Ricardo Wurmus <rekado@elephly.net> wrote:
>
>
> Han-Wen Nienhuys <hanwenn@gmail.com> writes:
>
> > Some of the lilypond Scheme files do the following:
> >
> >
> > (define decl '())
> > (define (make-var n v) (list "var" n v))
> > (defmacro define-session (name value)
> >   (define (inner n v)
> >     (set! decl
> >         (cons
> >          (make-var n v)
> >          decl))
> >     )
> >   `(,inner ',name ,value))
> > (define-session foo 1)
> > (display decl)
> > (newline)
> >
> > In GUILE 2.2, this yields
> >
> > ;;; WARNING: compilation of /home/hanwen/vc/lilypond/q.scm failed:
> > ;;; unhandled constant #<procedure inner (a b)>
> >
> > What does this error message mean, and what should I do to address the problem?
>
> Would it be feasible to use define-syntax-rule here?
>
> --8<---------------cut here---------------start------------->8---
> (define decl '())
> (define (make-var n v) (list "var" n v))
> (define-syntax-rule (define-session name value)
>   (let ((inner (lambda (n v)
>                  (set! decl
>                        (cons
>                         (make-var n v)
>                         decl)))))
>     (inner 'name value)))
> (define-session foo 1)
> (display decl)
> (newline)
> --8<---------------cut here---------------end--------------->8---
>
>
> --
> Ricardo



-- 
Han-Wen Nienhuys - hanwenn@gmail.com - http://www.xs4all.nl/~hanwen