[commit: ghc] master: Support wild cards in data/type family instances (d9d2102)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/d9d2102ea7f6da1bc3a69fa469b89ea843cb8b02/ghc

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

commit d9d2102ea7f6da1bc3a69fa469b89ea843cb8b02
Author: Thomas Winant <thomas.winant at cs.kuleuven.be>
Date:   Mon Aug 3 14:57:40 2015 +0200

    Support wild cards in data/type family instances
    
    Handle anonymous wild cards in type or data family instance
    declarations like
    unnamed type variables. For instance (pun intented):
    
        type family F (a :: *) (b :: *) :: *
        type instance F Int _ = Int
    
    Is now the same as:
    
        type family F (a :: *) (b :: *) :: *
        type instance F Int x = Int
    
    Note that unlike wild cards in partial type signatures, no errors (or
    warnings
    with -XPartialTypeSignatures) are generated for these wild cards, as
    there is
    nothing interesting to report to the user, i.e. the inferred kind.
    
    Only anonymous wild cards are supported here, named and
    extra-constraints wild
    card are not.
    
    Test Plan: pass new tests
    
    Reviewers: goldfire, austin, simonpj, bgamari
    
    Reviewed By: simonpj, bgamari
    
    Subscribers: goldfire, thomie
    
    Differential Revision: https://phabricator.haskell.org/D1092
    
    GHC Trac Issues: #3699, #10586


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

d9d2102ea7f6da1bc3a69fa469b89ea843cb8b02
 compiler/rename/RnSource.hs                        |  9 +++++-
 compiler/typecheck/TcTyClsDecls.hs                 | 35 ++++++++++++++++++++--
 docs/users_guide/7.12.1-notes.xml                  |  9 ++++++
 docs/users_guide/glasgow_exts.xml                  | 31 +++++++++++++++++++
 .../should_compile/DataFamilyInstanceLHS.hs        | 13 ++++++++
 .../should_compile/DataFamilyInstanceLHS.stderr    | 16 ++++++++++
 .../should_compile/TypeFamilyInstanceLHS.hs        |  9 ++++++
 .../should_compile/TypeFamilyInstanceLHS.stderr    | 13 ++++++++
 testsuite/tests/partial-sigs/should_compile/all.T  |  2 ++
 .../NamedWildcardInDataFamilyInstanceLHS.hs        | 10 +++++++
 .../NamedWildcardInDataFamilyInstanceLHS.stderr    |  4 +++
 .../NamedWildcardInTypeFamilyInstanceLHS.hs        |  5 ++++
 .../NamedWildcardInTypeFamilyInstanceLHS.stderr    |  4 +++
 .../should_fail/WildcardInTypeFamilyInstanceLHS.hs |  8 -----
 .../WildcardInTypeFamilyInstanceLHS.stderr         |  6 ----
 testsuite/tests/partial-sigs/should_fail/all.T     |  3 +-
 16 files changed, 159 insertions(+), 18 deletions(-)

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

    git diff-tree --root --patch-with-stat --no-color --find-copies-harder --ignore-space-at-eol --cc d9d2102ea7f6da1bc3a69fa469b89ea843cb8b02