#!/bin/sh
string=? ; exec mzscheme -g -l core.ss -r $0 "$@"

(if (file-exists? "average.ss")
    (require "average.ss")
    (error 'average "couldn't find average.ss"))

(define (L)
   (let [(n (read))]
      (cond
	 [(eof-object? n) empty]
	 [(number? n)     (cons n (L))]
	 [else            (error 'average "not a number: ~e~n" n)])))

(printf "The average is: ~s~n" (average (L)))