gistfile1.txt

(defmacro run (code evfun)
  `((lambda (code)
      (declare (optimize (speed 3))
               (type (simple-array fixnum (*)) code)
               (type function evfun)
               (inline ,evfun))
      (loop with steps = 0
            with ptr = 0
            with code = (copy-seq code)
            with code-length = (length code)
            until (exited? code-length ptr)
            do (progn (setf ptr (,evfun code ptr))
                      (incf (the fixnum steps)))
            finally (return steps)))
    ,code))