Watershed -- what's up ?

David Wragg dpw93@ecs.southampton.ac.uk
26 Oct 94 15:38:00 GMT

Francois-Rene Rideau writes:
>   Can you give me any news from your Watershed project ?
>   I'm currently trying to revive my own project, and would like to know
> where yours is, if we can merge, etc.
>   Thanks.

The news is ... not much.

A few weeks after I had gone public and gathered opinions about the
project I went on a long holiday away from the Internet, and I had a
lot of time to think about the design. So some things changed quite a
lot. The most important thing - what I want it to be like in use has
remained the same.

For a lot of efficiency reasons, I would now like to make the system
pure functional, and so its roots have gone from being in OO languages
to being in pure functional languages (such as Haskell and
Miranda). The attraction of pure functional semantics is that it makes
some important aspects of Watershed (the garbage collector and the
"transaction processing" model) much easier to think about, and

But pure functional semantics have a big problem - they don't go well
with user-interfaces, since user-interfaces rely heavily on a concept
of state.

I intend to stick with language independence (using the right language
for the right job at the right time) but I will need to write
something very like a functional language compiler. This will be a
difficult task (lazy functional language compilation is still very much
a research topic).

And that's about it. I'm confident that this is a "better" design than
the one I had before, but it relies on too many things that are still
being researched by people worldwide.

Perhaps we could merge, or at least exchange ideas. I'd be happy to
hlp with a project which has a better chance than Watershed of being
completed. (At the moment I'm thinking that writing Watershed might be
a good project for my doctorate, but that puts even early versions at
3+ years away).

Please write and tell me what your aims are. If you are interested,
I'll try to write out my current design more fully.

Dave W.