#!/usr/bin/guile \
-e main -s
!#
;;; Copyright 2005 Daniel Cer (daniel.cer@cs.colorado.edu)
;;;
;;; This work is licensed under the Creative Commons Attribution-NonCommercial-
;;; ShareAlike License. To view a copy of this license, visit 
;;; http://creativecommons.org/licenses/by-nc-sa/2.5/ or send a letter to 
;;; Creative Commons, 543 Howard Street, 5th Floor, San Francisco, California, 
;;; 94105, USA.

(define (fibonacci n)  
  (cond 
  ((<= n 0) -1) ((<= n 2) 1)
  (else (+ (fibonacci (- n 1)) (fibonacci (- n 2))))))

(define (main args) 
 (if (eqv? (length args) 2) 
   (let ((n (string->number (car (cdr args))))) 
   (display (string-append "fibonacci(" 
       (number->string n) "): " 
       (number->string (fibonacci n)) "\n")))
   (display 
   (string-append "Usage:\n\t" (car args) "(n-th fibonacci # to calculate)\n"))))