[commit: ghc] master: Eta-reduce data/newtype family instance axioms (Trac #4185) (827cc50)

[Simon Peyton Jones]

Repository : http://darcs.haskell.org/ghc.git/

On branch  : master

https://github.com/ghc/ghc/commit/827cc509fe9d4ccff2874913b73df4d659f3e785

>---------------------------------------------------------------

commit 827cc509fe9d4ccff2874913b73df4d659f3e785
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Thu May 30 13:56:07 2013 +0100

    Eta-reduce data/newtype family instance axioms (Trac #4185)
    
    This long-overdue fix arranges to eta-reduce the axiom for a
    data/newtype instance in the same way that we have longq
    eta-reduced the axiom for a newtype.
    
    See Note [Eta reduction for data family axioms] in TcInstDcls
    and Note [Deriving, type families, and partial applications] in TcDeriv.

 compiler/typecheck/FamInst.lhs    |  49 +-------------
 compiler/typecheck/TcDeriv.lhs    | 135 ++++++++++++++++++++++++--------------
 compiler/typecheck/TcInstDcls.lhs |  43 +++++++++++-
 compiler/types/FamInstEnv.lhs     |  55 ++++++++++------
 4 files changed, 163 insertions(+), 119 deletions(-)


Diff suppressed because of size. To see it, use:

    git show 827cc509fe9d4ccff2874913b73df4d659f3e785