Disan

Its only command, D, implements the Disan Count.

Examples

Implement the Disan Count

D

Interpreter

The following implementation is realized in Common Lisp:

(defun interpret-Disan (code)
  "Interprets the piece of Disan CODE and returns NIL."
  (declare (type string code))
  (loop for token of-type character across code do
    (if (char= token #\D)
      (let ((n (parse-integer (read-line))))
        (declare (type integer n))
        (let ((a 0))
          (declare (type integer a))
          (loop while (< a n) do
            (when (evenp a)
              (format T "~&~d is even!" a))
            (incf a 1))))
      (error "Invalid character: \"~c\"." token))))