patch applied (ghc): Fix and improve deriving for indexed data types

[email protected] Thu, 4 Jan 2007 17:30:32 -0800

Newsgroups	gmane.comp.lang.haskell.cvs.all,gmane.comp.lang.haskell.cvs.ghc
Message-ID	<[email protected]>

Wed Jan  3 17:31:56 PST 2007  Manuel M T Chakravarty <[email protected]>
  * Fix and improve deriving for indexed data types
  - The test for being able to derive the requested classes needs to be made
    with the representation tycon (not the family tycon).
  - Standalone deriving for indexed types requires the instance types in the
    derive clause to match a data/newtype instance exactly (modulo alpha).

    M ./compiler/typecheck/TcDeriv.lhs -25 +35
    M ./compiler/typecheck/TcEnv.lhs -5 +13
    M ./compiler/types/FamInstEnv.lhs -46
    M ./compiler/types/Type.lhs -1 +8