[commit: ghc] master: Improve occurs-check error reporting (fix Trac #6123) (05289c2)

[Simon Peyton Jones]

Repository : ssh://darcs.haskell.org//srv/darcs/ghc

On branch  : master

http://hackage.haskell.org/trac/ghc/changeset/05289c2ac1203a5d5bbe8236d0239946b5093116

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

commit 05289c2ac1203a5d5bbe8236d0239946b5093116
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Fri May 25 11:45:53 2012 +0100

    Improve occurs-check error reporting (fix Trac #6123)
    
    We were wrongly reporting (a ~ F a) as an occurs-check error
    when F is a type function.

 compiler/typecheck/TcCanonical.lhs |  112 ++++++++++++++++++-----------------
 compiler/typecheck/TcErrors.lhs    |   41 ++++++--------
 compiler/typecheck/TcInteract.lhs  |    5 ++
 3 files changed, 80 insertions(+), 78 deletions(-)


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

    git show 05289c2ac1203a5d5bbe8236d0239946b5093116