[m-dev.] for review: change library to use existential types

[Fergus Henderson]

On 19-Nov-1998, David Glen JEFFERY <dgj at cs.mu.OZ.AU> wrote:
> 
> > +	% XXX what is the right TYPE_QUAL_OP to use here?
> > +	io__write_string(" : "),
> 
> Good question. Is ":" the right thing to use for now?

Currently it doesn't matter too much what we use, because
you can write univs but you can't read them back in again.

In the long term I think ":" is the right thing to use.

> > +io__write_c_pointer(_C_Pointer) -->
> > +	% XXX what should we do here?
> > +	io__write_string("'<<c_pointer>>'").
> 
> Another good question. Perhaps we should print out the pointer value. (?)

Can't do that, because io__write is declared `det' not `cc_multi',
and different pointer values might well represent the same abstract value.

In the long term we need an `io__write_cc' or something like that
which can show representation details rather than (or as well as)
the abstract values.

-- 
Fergus Henderson <fjh at cs.mu.oz.au>  |  "Binaries may die
WWW: <http://www.cs.mu.oz.au/~fjh>  |   but source code lives forever"
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