FORMAT-GRAPH-FROM-ROOT in a REDIPLAYER...

["RDP@ALAN.LAAC-AI.Dialnet.Symbolics.COM" <"RDP%ALAN.LAAC-AI.Dialnet.Symbolics.COM %ALAN.KAHUNA.DECNET.LOCKHEED.COM"@WARBUCKS.AI.SRI.COM>]

Date: Thu, 3 Aug 89 09:24 PDT
From: Robert D. Pfeiffer <RDP@ALAN.LAAC-AI.Dialnet.Symbolics.COM>
Subject: FORMAT-GRAPH-FROM-ROOT in a REDIPLAYER...
To: SLUG@ALAN.LAAC-AI.Dialnet.Symbolics.COM
In-Reply-To: Your message of 2 Aug 89 20:41 PDT
Message-ID: <19890803162423.2.RDP@ALAN.LAAC-AI.Dialnet.Symbolics.COM>
 
    Date: Wed, 2 Aug 89 12:36:09 PDT
    From: felix@Warbucks.AI.SRI.COM (Francois Felix INGRAND)
 
    I have an application were I want to display a graph which is
    constantly changing.  The content of the nodes is also changing...
 
    I tried to make a format-graph-from-root in a redisplayer and did not
    have that much success... The screen get messy with garbages coming
    from the different redisplay passes. 
 
    Is it suppose to work? or is it hopeless?  I thought I saw an example
    like that in the Documentation, but I cannot find it anymore.
 
    I would appreciate any hints or code example dealing with such
    problem. 
 
    Felix
 
It's definitely supposed to work and, after some initial stumbling, I've been
fairly successful in doing these kinds of things.  The biggest problem
is debugging.  It can be very hard (I find) to relate a symptom to a
cause when using a lot of the sophisticated functionality together.  My
approach is to start from a working example and then to keep making and
debugging small changes until I've transformed it into what I want.
That way, when something strange happens, I can identify what I just
broke.
 
See the section "Incremental Redisplay of Graphs" for an useful example.
 
BIG DEBUGGING HINT:  Make sure you always supply the same stream
argument to all functions involved.