On Aug 31, 2010, at 12:03 PM, michael rice wrote:
I tried creating an instance earlier but
*Main> :t (->) Int Char
<interactive>:1:1: parse error on input `->'
Try: Prelude> :info (->) data (->) a b -- Defined in GHC.Prim If you want type-information about values, use :t. If you want information about types (and the "type-level language"), use :info. This includes stuff like class definitions and instances in scope. For example, if I include Control.Monad: Prelude Control.Monad.Instances> :info (->) data (->) a b -- Defined in GHC.Prim instance Monad ((->) r) -- Defined in Control.Monad.Instances instance Functor ((->) r) -- Defined in Control.Monad.Instances :info is pretty cool: Prelude Control.Monad.Instances> :info Monad class Monad m where (>>=) :: m a -> (a -> m b) -> m b (>>) :: m a -> m b -> m b return :: a -> m a fail :: String -> m a -- Defined in GHC.Base instance Monad ((->) r) -- Defined in Control.Monad.Instances instance Monad Maybe -- Defined in Data.Maybe instance Monad [] -- Defined in GHC.Base instance Monad IO -- Defined in GHC.Base