[Haskell-cafe] is Haskell missing a non-instantiating polymorphic case? (missing link added)

Adam Megacz megacz at cs.berkeley.edu
Mon Oct 24 04:30:32 CEST 2011

On 2011-10-23 17:02:47 -0700, Brandon Moore said:
> It sounds like the entire point of this is syntax representation?

Not really...... the entire point of this is parametricity. :)

There are a lot of examples involving syntax and binding because ruling 
out exotic terms is one of the things that parametricity is really 
useful for.

> If so, have you seen Conor McBride's recent post
> http://www.e-pig.org/epilogue/?p=773

Yes, a while back; it's very cool but basically orthogonal: the data 
types in that blog post aren't indexed by the object-language-term's 
type (nor should they be -- he's writing a typechecker, after all!).

  - a

More information about the Haskell-Cafe mailing list