From: Andreas Abecker
Subject: Interface between TCL/TK and COMMON LISP
Date: 
Message-ID: <1rg5ecINNm36@serv-200.dfki.uni-kl.de>
In a project implementing high declarative expert system tools we are
looking for a LISP-extension enabling us to build a good graphical user
interface for our algorithms.

The framework we are looking for should provide graphical interface
building on a high level of abstraction. It should be rather portable 
and therefore, public domain. Furthermore it should not slow down the
LISP too much by its space or processor time consumption.

A very promising hint was to use Tcl/Tk. Tcl is an interpreted,
string-based language that is available on a large number of platforms.
Tk is an X toolkit based on Tcl, i.e., widgets, handlers, etc. are all
available through that language. The ftp site for officially released
material is harbor.ecn.purdue.edu (/pub/tcl).

NOW THE PROBLEM IS: How should the LISP process and the
Tcl/Tk interpreter communicate such that:
	- data flow is bidirectional
	- the Tcl/Tk interpreter is started from Lisp
	  (simpler debugging than starting both from one process)
	- the communication interface is small and fairly portable
	  (at the moment we are looking for a lucid and a clisp solution)

For example, it should be possible to mark an object - being a part of
a graph drawn by TCL - as an input for a LISP function and the result
of this function causes a redrawing of the graph.

We feel that a rather similar problem should arise each time 
someone wants to set a TCL/TK user interface on top of an application
program that was originally designed as a stand alone product.

Thanks for all suggestions.
Please mail directly to ········@dfki.uni-kl.de .
I'll summarize.

Best regards, Andreas