Updated my little type-level 2s and 16s complement integer library to be ghc 6.6 friendly and uploaded it to hackage based on popular (er.. ok, well, singular) demand.
O.K. it was more of a polite request, but I did update it.
July 2007
Monthly Archive
Fri 13 Jul 2007
Updated Data.Type.*
Posted by Edward Kmett under Haskell , Type Hackery , UncategorizedComments Off
Fri 13 Jul 2007
Parameterized Monads in Haskell
Posted by Edward Kmett under Haskell , Monads , Type Theory[5] Comments
Recently Eric Kidd and Dan Piponi have used a bit of type hackery by Oleg Kiselyov and -fno-implicit-prelude to build some interesting restricted monads, like the Wadler Set and Bag monads.
There is another interesting monad variation - a parameterized monad - where the monad carries around an additional parameter at the type level such as a type-level set of effects. One really good example of this is the separation logic monad in Hoare Type Theory. The pre- and post- conditions can be viewed as the parameter carried around on that monad. Wadler and Thiemann, Jean-Christophe Filliâtre and others have explore this notion for encoding effects.