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From: ALarson@HI-MULTICS.ARPA.UUCP
Newsgroups: comp.emacs
Subject: Redisplay hooks in GNU
Message-ID: <870302154746.568447@HI-MULTICS.ARPA>
Date: Mon, 2-Mar-87 10:47:00 EST
Article-I.D.: HI-MULTI.870302154746.568447
Posted: Mon Mar  2 10:47:00 1987
Date-Received: Tue, 3-Mar-87 22:28:55 EST
Sender: daemon@ucbvax.BERKELEY.EDU
Distribution: world
Organization: The ARPA Internet
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I appologize if this question has been raised before, but I'm new to the
list ...

I am looking for a way to do parenthesis highlighting in a manner
similar to the way the lisp machines work.  Whenever the cursor appears
on a parenthesis, the mate is highlighted.  I could not find any
mechanism to do this in our version of GNU (17.33), so I added some
redisplay hooks.  I was able to get this working reasonably well, but it
is obvious that a better understanding of the redisplay code is
necessary to do it right.  The main problem being that most of the
screen management routines are C based, and I was hoping to write the
hooks in lisp.  This would require either exporting the C routines to
lisp, or defining a protocol for the hook to return an expression, then
having the C routines munge the display accordingly.

So, before I dive into the redisplay code any further, my question is 
this: 

   Does anyone have code that implements redisplay hooks right, or a
   better idea of how to do the paren matching?

Aaron Larson    ALarson@HI-Multics