deriving over renamed types

3 Apr 2002


      Why can't I do this:
...
import FiniteMap
type FM = FiniteMap
instance (Show a, Show b) => Show (FiniteMap a b) where
    show = show . fmToList
data X = X (FM Int Int)
       deriving (Show)
if I replace
...
type FM = FiniteMap
with
...
type FM a b = FiniteMap a b
it works fine.  I wasn't aware there was (supposed to be) a difference
between these two declarations?  Is there?

 - Hal


--
Hal Daume III

 "Computer science is no more about computers    | hdaume@isi.edu
  than astronomy is about telescopes." -Dijkstra | www.isi.edu/~hdaume