[commit: ghc] master: Make type-level evaluation work with :kind! (b2fa2d4)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/b2fa2d41032882d3cf67be083489cbcbf9e4ec07/ghc

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

commit b2fa2d41032882d3cf67be083489cbcbf9e4ec07
Author: Iavor S. Diatchki <diatchki at galois.com>
Date:   Tue Nov 12 16:36:23 2013 -0800

    Make type-level evaluation work with :kind!
    
    The main change is to add a case to `reduceTyFamApp_maybe` to evaluate
    built-in type constructors (e.g., (+), (*), and friends).
    
    To avoid problems with recursive modules, I moved the definition of
    TcBuiltInSynFamily from `FamInst` to `FamInstEnv`.  I am still not sure if
    this is the right place.
    
    There is also a wibble that it'd be nice to fix:
    
    when we evaluate a built-in type function, using`sfMatchFam`, we get
    a `TcCoercion`.  However, `reduceTyFamApp_maybe` needs a `Corecion`.
    I couldn't find a nice way to convert between the two, so I resorted to
    a bit of hack (marked with `XXX`).
    
    The hack is that we happen to know that the built-in constructors for
    the type-nat functions always return coercions of shape `TcAxiomRuleCo`,
    with no assumptions, so it easy to convert `TcCoercion` to `Coercion`
    in this one case.  This is enough to make things work, but it is clearly
    a cludge.


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

b2fa2d41032882d3cf67be083489cbcbf9e4ec07
 compiler/ghc.mk                                    |    2 +-
 compiler/typecheck/FamInst.lhs                     |   27 +-----------
 compiler/typecheck/TcInteract.lhs                  |    2 +-
 compiler/typecheck/TcTypeNats.hs                   |    2 +-
 compiler/types/FamInstEnv.lhs                      |   43 +++++++++++++++++++-
 .../FamInst.lhs-boot => types/FamInstEnv.lhs-boot} |    2 +-
 compiler/types/TyCon.lhs                           |    2 +-
 7 files changed, 47 insertions(+), 33 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 b2fa2d41032882d3cf67be083489cbcbf9e4ec07