George Russell wrote:
I'm sorry if this is a FAQ, but I'm curious to know why Haskell (or at least, GHC and Hugs) doesn't seem able to use contexts on variables at the front of data declarations.
There has been some discussion on contexts on data declarations during the Haskell 98 standardization process. See: http://www.cs.chalmers.se/~rjmh/Haskell/Messages/Display.cgi?id=302 I think this discussion also lead John Hughes to write his paper on "Restricted Datatypes in Haskell" which is available from his homepage: http://www.cs.chalmers.se/~rjmh/ Hope this helps, - Andreas -- Andreas Rossberg, rossberg@ps.uni-sb.de "Computer games don't affect kids. If Pac Man affected us as kids, we would all be running around in darkened rooms, munching pills, and listening to repetitive music."