; Convert a char* to a Scheme string
; Extracted from this paper:
; http://scheme2011.ucombinator.org/papers/Keep2011.pdf
(define (char*->string fptr)
  (let f ([i 0])
    (let ([c (ftype-ref char () fptr i)])
      (if (char=? c #\nul) 
          (make-string i)
          (let ([str (f (fx+ i 1))])
            (string-set! str i c)str)))))

(define (alloc size fx)
  (let ([v (foreign-alloc size)])
    (fx v)
    (foreign-free v)))

(define (check-err ret msg)
  (cond
    ((< ret 0)
     (perror msg)
     (raise msg))
    (#t ret)))