(in-package :car)

;;;; ACL2 builtins (for automatic guards)

(defun zp (obj) (zerop obj))

(defun proper-consp (obj) "
:doc acl2-built-ins
"
 (and obj (consp obj)
  (null (cdr (last obj)))))



;;;; graphviz dot support

(defun dot-stobj (stobj &optional (stream t))
 (loop initially (format stream "digraph {~%")
  for node in (cdr (assoc 'nodes stobj))
  for exits = (cdr (assoc 'exits node))
  for id = (cdr (assoc 'id node))
  do (loop for exit in exits 
      do (format stream "~d -> ~d;~%" id exit))
  finally (format stream "}~%")))

(defun look (stobj)
 (with-open-file (out #p"tmp.dot" :direction :output)
  (dot-stobj stobj out))
 (uiop:run-program "dot -Tpng tmp.dot > tmp.png")
 (uiop:run-program "feh tmp.png")
 (delete-file "tmp.dot"))