[m-dev.] type classes --- thoughts?

[Fergus Henderson]

Zoltan Somogyi, you wrote:
> 
> I think univ should be like Ada's limited private; only permitted operation
> is assign (and univ_to_type of course).

If we don't provide some way for arg to work on univ, then it is
going to be impossible to use arg and functor to recursively traverse a
term, since arg itself returns a list(univ).

Thus, we need to provide a way to do this, even if it requires some dynamic
checking.

-- 
Fergus Henderson <fjh at cs.mu.oz.au>   |  "I have always known that the pursuit
WWW: <http://www.cs.mu.oz.au/~fjh>   |  of excellence is a lethal habit"
PGP: finger fjh at 128.250.37.3         |     -- the last words of T. S. Garp.