#!/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.

; read-entries - read in the list of new-line seperated numbers from an 
; input-port.  
(define (read-entries port) 
  (let ((in-line (read-line port))) 
  (if (eof-object? in-line) '()
      (append (list (string->number in-line)) (read-entries port)))))

; bubble-sort - returns a list with all of the items in the list 'entries'
; but with the items in ascending order.
(define (bubble-sort entries) 
  (do ((entries-vec (list->vector entries))
       (i (- (length entries) 1) (if (equal? (+ j 1) i) (- i 1) i))
       (j 0 (if (equal? (+ j 1) i) 0 (+ j 1))))
       ((equal? i 0) (vector->list entries-vec))
       (if (< (vector-ref entries-vec (+ j 1)) (vector-ref entries-vec j))
         (let ((swap-tmp (vector-ref entries-vec j)))
           (vector-set! entries-vec j (vector-ref entries-vec (+ j 1)))
           (vector-set! entries-vec (+ j 1) swap-tmp))))) 
       
(define (main args) (if (not (equal? (length args) 2)) (display 
     (string-append "Usage:\n\t" (car args) " (file with numbers to sort)\n"))
  (map (lambda (entry) (display entry) (newline))  ; display the sorted list
    (bubble-sort                                          ; sort everything
    (call-with-input-file (car (cdr args)) read-entries)) ; read in the items
)))