Re: List functions

[Marco Maggi]

"Hans Aberg" wrote:
> I am  writing on a parser that  translates normal function
> syntax in to Guile code.

I do not know which scenario you are working with, but it is
perfectly possible to convert the input syntax:

  ((sin , cos , tan) 1.2)

to the output:

  ((lambda args
     (map (lambda (f)
            (apply f args))
       (list sin cos tan)))
   1.2)

if you accept to write  the input syntax expressions only as
part of a  macro use, let's call this macro  H; so the macro
use:

  (h
   ((sin , cos) 1.2))

can be expanded to:

  ((lambda args
     (map (lambda (f)
            (apply f args))
       (list sin cos tan)))
   1.2)

  It is  also possible  to write the  H macro such  that any
expression with nested expressions  can appear in its use; H
can be  made just  like the built  in syntax BEGIN  but with
syntax different from standard Scheme.  Example:

  (h
   (display (+ 4 ((sin , cos) 1.2))))

  Once  you have  H you  can write  a DEFINE/H  syntax which
works just like the standard  DEFINE but accepts in its body
the modified syntax:

  (define/h (doit x y)
   (display (+ x ((sin , cos) y))))

  The tool to do it is the syntax-case macro system.

HTH
-- 
Marco Maggi