| Allegro CL version 6.1 Unrevised | |||||||||
Arguments: x
Returns true if the argument is an instance of the class window and that window
is still open (has not been closed). In releases prior to 6.0, window
objects changed class when they were closed, so any instance of
window was
automatically open. In release 6.0, window objects do not change class
when closed. The change in the behavior of windowp thus preserves the
pre-6.0 behavior.
windowp also checks that the process that created the window is still
in the *all-processes* list, and returns
true only if it is. (If a thread where a window is created is
destroyed, the window object may still look open even though it is
closed for all intents and purposes.)
Copyright (c) 1998-2001, Franz Inc. Berkeley, CA., USA. All rights reserved.
Documentation for Allegro CL version 6.1 update # 1. This page was not revised.
Created 2001.12.15.
| Allegro CL version 6.1 Unrevised | |||||||||