(define $main
  (lambda [$:]
    (do {[$: (print : "input char : ")]
         [[$: $c] (read-char :)]
         [$: (print : "output : ")]
         [$: (write-char : c)]
         [$: (write-char : '\n')]
         [$: (print : "input number :")]
         [[$: $e] (read :)]
         [$: (print : "output : ")]
         [$: (write : e)]
         [$: (write-char : '\n')]}
      :)))

(execute)


(define $main
  (lambda [$:]
    (do {[$: (print : "Return world? (y/n) : ")]
         [[$: $c] (read-char :)]}
        (match c Character
          {['y' :]
           ['n' 0]}))))

(execute)


(define $main
  (lambda [$:]
    (do {[$: (print : "Return world? (1/0) : ")]
         [[$: $n] (read :)]}
        (match n Integer
          {[,1 :]
           [,0 0]}))))

(execute)