[m-dev.] subtyping proposal (repost)

[Fergus Henderson]

On 09-Feb-2000, Ralph Becket <rbeck at microsoft.com> wrote:
> > 	For polymorphically typed predicates, we could
> > 	propagate type information into the modes so that all
> >	polymorphically typed predicates also become polymorphically moded.
> 
> Would this mode propagation render the now polymorphic mode
> declarations redundant, then?

No.  As mentioned in the part that you snipped, in general it's not
safe to do that kind of automatic propagation for polymorphic types
which are type class constrained.  So explicit polymorphic modes
declarations would still be necessary for those cases of predicates
which take type class constrained polymorphic types and which are
also polymorphically moded.

-- 
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.
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