Re: [ikarus-users] Procedure arity in macros

[leppie]

From: "leppie" <xacc....@gmail.com>

I am trying to write a proof of concept quick  :)


Here is something that seems to work.

(library (smart-curry)
(export
 smart-curry smart-aux) ;; must export samrt-aux for eval to work
(import
 (ironscheme)) ;; for procedure-arity

 (define-syntax curry
   (lambda (x)
     (syntax-case x ()
       [(_ proc arg ...)
         (let f ((args #'(arg ...)))
           (if (null? args)
               #'(lambda () (proc arg ...))
               #`(lambda (#,(car args)) #,(f (cdr args)))))])))

 (define-syntax smart-aux
   (lambda (x)
     (syntax-case x ()
       [(_ n)
         (with-syntax (((arg ...) (generate-temporaries
                                    (make-list (syntax->datum #'n)))))
           #'(lambda (f) (curry f arg ...)))])))

 (define (smart-curry x)
   ;; todo all kinds of checks
   (let ((n (procedure-arity x)))
     ((eval `(smart-aux ,n) (environment '(smart-curry))) x))))

Usage:

(import (smart-curry))
(define vector-set!* (smart-curry vector-set!))
(define v (make-vector 5 0))
((((vector-set!* v) 1) 'boo))

I never use currying, so I am not sure if the semantics is exactly what you 
are looking for  :)

Cheers

leppie