About "class Coerce a b" - errata

[Nick Name]

On Fri, 21 Feb 2003 08:05:37 +0100
Nick Name <nick.name@inwind.it> wrote:

> -- Does not type if overlapping instances are allowed
>  --
>  --instance Functor SList where
>  --    fmap f End = End
>  --    fmap f (a:::as) = (call f a):::(fmap f as)

I skipped the declaration of SList, which is the coolest part of the
story to my eyes:

data SList a = forall b . (Subtype b a) => (:::) b (SList a) | End

This is a list holding values of subtypes of a.

Vincenzo