Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cornell!batcomputer!rpi!turing.cs.rpi.edu!mcintyre
From: mcintyre@turing.cs.rpi.edu (David McIntyre)
Newsgroups: comp.lang.visual,comp.lang.misc
Subject: Re: metaphor and programming
Message-ID: <1989Nov17.040858.22886@rpi.edu>
Date: 17 Nov 89 04:08:58 GMT
References: <13770@orstcs.CS.ORST.EDU> <7000@ficc.uu.net>
Reply-To: mcintyre@turing.cs.rpi.edu (David McIntyre)
Organization: Rensselaer Instipoly Technitute
Lines: 23

In article <7000@ficc.uu.net> peter@ficc.uu.net (Peter da Silva) writes:
>I think visual languages would be most closely related to the dataflow
>metaphor. That is the most dimensionally ordered one. Think of building
>UNIX shell programs by fitting together pipes to little tanks called
>"awk" and "sed"...
>

I am not so sure about this.  Let's stay with the example of a Unix pipe
"program".  This is always a one-dimensional flow of data.  I am not
sure that a visual representation of this would add anything, although
it might make building pipes more fun.

The visual programming system I have worked on, SunPict, views programs
procedurally, mapping program statements to icons on the screen.  I
think that this control flow visualization adds much more to the 
understanding of programs.  Control flow is obviously not only
one-dimensional.  Between conditional statements and function calls,
a two (or more) dimensional mapping adds a lot.
  
Dave "mr question" McIntyre     |      "....say you're thinking about a plate
mcintyre@turing.cs.rpi.edu      |       of shrimp.....and someone says to 
office : 518-276-8633		|	you `plate,' or `shrimp'......"
home   : 518-271-6664		|