ball.lisp

#!/bin/sh
#|-*- mode:lisp -*-|#
#|
exec ros -Q -- $0 "$@"
|#
(progn ;;init forms
  (ros:ensure-asdf)
  #+quicklisp(ql:quickload '(:iterate) :silent t)
  )

(defpackage :ros.script.ballfun.3804742596
  (:use :cl :iterate))
(in-package :ros.script.ballfun.3804742596)

(defun main (&rest argv)
  (declare (ignorable argv))
  (let ((*wx* (pop argv))
        (*wy* (pop argv)))
    (format t "rectangle: (~A,~A)~%" *wx* *wy*)
    (iter
      (for i from 1)
      (with wx = *wx*)
      (with wy = *wy*)
      (with xacc = 1)
      (with yacc = 1)
      (for x :initially 1 :then (+ x xacc))
      (for y :initially 1 :then (+ y yacc))
      (format t "~A: (~A,~A)~%" i x y)
      (if-first-time
       nil
       (progn
         (when (or (eq x 1) (eq x wx)) (setf xacc (- xacc)))
         (when (or (eq y 1) (eq y wy)) (setf yacc (- yacc)))))
      (if-first-time
       nil
       (until (or (and (eq x 1) (eq y 1))
                  (and (eq x 1) (eq y wy))
                  (and (eq x wx) (eq y 1))
                  (and (eq x wx) (eq y wy)))))
      (finally (format t "GOAL!~%") (list x y))))
  )
;;; vim: set ft=lisp lisp: