NetNews Usenet Archive 1992 #16/NN_1992_16.iso/spool/comp/lang/prolog/1440

Internet Message Format | 1992-07-22 | 1.6 KB

Path: sparky!uunet!mcsun!uknet!edcastle!edcogsci!asch
From: [e-mail] (Andreas Schoter)
Newsgroups: comp.lang.prolog
Subject: Re: Prolog-WIMP interfacing principles
Message-ID: <[e-mail]>
Date: 22 Jul 92 08:49:34 GMT
References: <[e-mail]>
Organization: Centre for Cognitive Science, Edinburgh, UK
Lines: 25

In article <[e-mail]> [e-mail] (Paul Singleton) writes:
>Please can anyone with experience or insight suggest some principles
>for interfacing Prolog programs to WIMP interfaces, i.e. buttons, sliders,
>menus, dialog boxes and all that stuff.  I avoid asserting and retracting
>global state, and try to contain side-effects, and I can't see how to
>employ WIMP features without compromising this style.  Well, I can, but ...

You don't specify what level of abstraction the WIMP features are
specified at, low level wiget type facilities, or high level packaged
utilityies, but...

Last summer I did some work at Sussex with the Poplog Prolog system
interfacing it to the Athena X system.  There was already an interface
for the Pop11 language so what I did was to hook the Prolog into the
Pop11.  The net result was a set of new "builtin" predictes in Prolog
which behaved like write/1 etc.  (Admitedly much of this took advantage
of the Pop11 datastructures to store wiget info thus avoiding explicit
asserts and retracts at the Prolog end).

Yes, these are, strictly, side effect predicates, but I don't see
anyway around that.  If your Prolog has a good C interface the same
technique should work, hook Prolog predictes into foreign language
functions that perform the necessary graphics.

Andreas