Type checking is decidable for all of the lambda cube, but not type inference.
Haskell 98 is a subset of Fw, Haskell with extensions is an superset of Fw.
-- Lennart
On Mon, May 25, 2009 at 12:59 PM, Brent Yorgey
On Sun, May 24, 2009 at 10:39:50AM +0200, Petr Pudlak wrote:
On Sun, May 24, 2009 at 12:18:40PM +0400, Eugene Kirpichov wrote:
Haskell has terms depending on types (polymorphic terms) and types depending on types (type families?), but no dependent types.
But how about undecidability? I'd say that lambda2 or lambda-omega have undecidable type checking,
I don't think that's true. Unless I am mistaken, type checking is decidable for all the vertices of the lambda cube.
(BWT, will some future version of Haskell consider including some kind of dependent types?)
I doubt it. But there is a lot of current research into bringing as much of the power of dependent types into the language (e.g. type families) without actually bringing in all the headaches of full-spectrum dependent types.
-Brent _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe