Existentials
Malcolm Wallace
Malcolm.Wallace@cs.york.ac.uk
Thu, 17 Apr 2003 16:16:34 +0100
"Simon Marlow" <simonmar@microsoft.com> writes:
> > The example I tried failed, so I assumed it wasn't supported.
>
> You've written an existential constructor. For universal
> quantification, write it like this:
>
> data T = Foo (forall a . Enum a => a -> a)
>
> a good illustration of the confusion caused by the dual use of forall, I
> guess :-)
Exactly so. :-) If we change the syntax of existentials, would it
be possible to write my local universal example as I did originally
and have it work as expected? Or will it still be necessary to push
the quantifier inside the constructor?
Regards,
Malcolm