Type Pattern-Matching for Existential Types

Ashley Yakeley ashley@semantic.org
Tue, 30 Jan 2001 22:30:17 -0800

At 2001-01-30 22:16, Lennart Augustsson wrote:

>It has large and horrible implications.  To do dynamic type tests you need
>to carry around the types at runtime.  This is not something that Haskell
>does (at least you don't have to).

Hmm. In this:

data Any = forall a. Any a

a1 = Any 3
a2 = Any 'p'

...are you saying that a1 and a2 do not have to carry types at runtime?

Ashley Yakeley, Seattle WA