[m-dev.] Here's an idea.

[Fergus Henderson]

Tyson Richard DOWD, you wrote:
> > However, I'm not really sure exactly how it would interact with
> > type inference, maybe we should try it out and get some experience with
> > it.
> 
> This could still be worthwhile. Perhaps it's worth adding a heterogenous
> list type to the library (or to a library), and playing with some
> different syntaxes.

Well, if you want to try it out, one worthwhile experiment would be to add
the heterogenous list type into library/io.m, where it will get imported
into everything, and see what breaks.

(I'm not suggesting you commit it in io.m, just that you try it out there.)

> Or we could throw it to the wolves (mercury-users, that is ;-)

That's not a bad idea either.

> Also, C style formatting strings are pretty important, as almost every
> programmer is familiar with them. You would need to provide something 
> _significantly_ better to get people to change (I think in this case,
> "worse is better" is appropriate).

Yes, that's a good point.

> > The '|+' is kinda baroque syntax, though.
> 
> This isn't bad at all - it's certainly pretty easy to use, and easy to
> implement.
> (I assume you mean for this to be actually implemented as a list(univ)).

Yep.  Although it should really be list(printable), where printable
is defined as

	:- type printable == univ. % for now

but defined differently when we have type classes and existential types.

-- 
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.