> I've become interested in visual programming languages, but a bit
> disappointed that visual notation tends to be based on topological
> rather than geometrical relationships.
I think you need to define a little more carefully what you mean
by 'geometrical relationships'. Within the theory of visual
languages community, there are many formalisations that include
information other than node-link connectivity. Check out Marriott
and Meyer's book for an overview of other approaches.
> ... In fact the only example of a
> computer language using geometrical notation I've found is the
> ReacTable and the related TurTan, which use relative orientation and
> proximity of symbols. Are there others?
Those two systems are from the same research group, and based on
the same ideas. Symbol orientation is a very natural interaction
technique with a tangible interface such as the one this group
have created, but not so convenient when using a mouse.
> Also, perhaps a more interesting question is, why aren't there more?
> I can see why you wouldn't want (practically) continuous parameters of
> distance involved in business logic, but how about programming
> languages for use in the arts?
Well, I guess your examples are both in the arts. What about
other domains? A natural place to look might be interactive
geometry tutors, computer aided design, or any other area where
geometry is significant.
Reader in Interdisciplinary Design, University of Cambridge
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