mortal

mortal.scm

#!/usr/local/bin/gosh                                                                                                                                                                                                                

(use srfi-1) ; list-index                                                                                                                                                                                                          
(use srfi-14) ; char-set                                                                                                                                                                                                           
(use math.mt-random)
(use gauche.parseopt)

(define (usage)
  (print "Usage: mortal [options ...]")
  (print "  - s|sleep : milli second sleep")
  (print "  - l|length")
  (print "  - h|help")
  (exit 0))

(define (make-lookupper keys values :optional (comp eq?))
  (^ (key)
     (let1 idx (list-index (pa$ comp key) keys)
       (and idx (list-ref values idx)))))

(define rand
  (let1 m (make <mersenne-twister> :seed (sys-time))
    (^ (:optional (len 2))
       (mt-random-integer m len))))

(define (main args)
  (let-args (cdr args)
      ((n "s|sleep=i" 1000)
       (len "l|length=i")
       (help "h|help" => usage))
  (let* ((src1 (char-set->list #[a-zA-Z0-9]))
        (src2 (char-set->list #[ａ-ｚＡ-Ｚ０-９]))
        (lookup (make-lookupper src1 src2)))
    (let1 body (^ _ (sys-nanosleep (* n 100000))
                  (let1 char (list-ref src1 (rand (length src1)))
                    (display (if (zero? (rand 2))
                                 char
                                 (lookup char)))
                    (flush)))
      (if len
          (for-each body (iota len))
          (while #t (body)))))))