Re: [Chicken-users] Chicken 4: how to generate toplevel definitions?

[Mario Domenech Goulart]

On Mon, 25 Aug 2008 14:55:16 +0200 Peter Bex <address@hidden> wrote:

> On Mon, Aug 25, 2008 at 09:47:18AM -0300, Mario Domenech Goulart wrote:
> > 
> > Is it possible with chicken 4 to generate toplevel (or module-level)
> > definitions from a macro (explicit renaming)?
> > 
> > I mean, I'd like something like:
> > 
> >   (module gen-things *
> >   
> >     (define-syntax gen-thing
> >         (lambda (thing)
> >           `(define ,thing (lambda () (display "hello")))))
> >   
> >     (gen-thing one-thing)
> >   )
> > 
> > So I could use `one-thing' from module `gen-things'.
> 
> I think all you need to do is change the macro a bit (untested):
> 
> (define-syntax gen-thing
>    (lambda (exp r cmp)
>      (let ((thing (cadr exp)))
>       `(,(r 'define) ,thing (,(r 'lambda) () (,(r 'display) "hello"))))))

Thanks, Peter.  It works.  I just had to add `(import scheme)' to get
the R5RS stuff.  So, the complete example is:

  (module gen-things (one-thing)
  
    (import scheme)
    
    (define-syntax gen-thing
      (lambda (exp r cmp)
        (let ((thing (cadr exp)))
          `(,(r 'define) ,thing (,(r 'lambda) () (,(r 'display) "hello"))))))
  
    (gen-thing one-thing)
    )


Usage:

$ csi -n

CHICKEN
(c)2008 The Chicken Team
(c)2000-2007 Felix L. Winkelmann
Version 4.0.0x - linux-unix-gnu-x86     [ manyargs dload ptables applyhook ]
SVN rev. 11756  compiled 2008-08-25 on ze-dureza (Linux)

#;1> ,l gen-things.scm
; loading gen-things.scm ...
; loading /usr/local/chicken-hygienic/lib/chicken/4/scheme.import.so ...
#;1> (import gen-things)
#;2> (one-thing)
hello


Or (compiled):

$ csc -s gen-things.scm

$ csi -n

CHICKEN
(c)2008 The Chicken Team
(c)2000-2007 Felix L. Winkelmann
Version 4.0.0x - linux-unix-gnu-x86     [ manyargs dload ptables applyhook ]
SVN rev. 11756  compiled 2008-08-25 on ze-dureza (Linux)

#;1> ,l gen-things.so
; loading gen-things.so ...
; loading /usr/local/chicken-hygienic/lib/chicken/4/scheme.import.so ...
#;1> (import gen-things)
#;2> (one-thing)
hello


Best wishes.
Mario