(define-module (agar util)
  #:use-module (system foreign)
  #:export (with-string-inputs))

(define (with-string-inputs ptr-nums fn)
  (define (ptrfy-inputs arglist count)
    (cond
     [(null? arglist) '()]
     [(memq count ptr-nums)
      (cons (if (not (car arglist)) %null-pointer (string->pointer (car arglist)))
	    (ptrfy-inputs (cdr arglist) (1+ count)))]
     [else
      (cons (car arglist)
	    (ptrfy-inputs (cdr arglist) (1+ count)))]))
  (lambda args
    (apply fn (ptrfy-inputs args 0))))