[commit: base] master: Revert "Add code to convert from representation types, to existentially quantified singletons." (216d590)

[Ian Lynagh]

Repository : ssh://darcs.haskell.org//srv/darcs/packages/base

On branch  : master

https://github.com/ghc/packages-base/commit/216d59079cf33647d677b1314e693a49f9e515a8

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

commit 216d59079cf33647d677b1314e693a49f9e515a8
Author: Ian Lynagh <ian at well-typed.com>
Date:   Fri May 31 00:08:51 2013 +0100

    Revert "Add code to convert from representation types, to existentially quantified singletons."
    
    This reverts commit f7fb908ad963f7180c30b55fba57a858b0391de4.
    
    It causes a valdiate failure:
    
    *** Core Lint errors : in result of Simplifier ***
    <no location info>: Warning:
        In the expression: f_aqM
                             (x_aqF
                              `cast` (GHC.TypeLits.NTCo:SingI[0] <k_aKs> <n_aKt>
                                      :: GHC.TypeLits.SingI k_aKs n_aKt
                                           ~#
                                         GHC.TypeLits.Sing k_aKs n_aKt))
        From-type of Cast differs from type of enclosed expression
        From-type: GHC.TypeLits.SingI k_aKs n_aKt
        Type of enclosed expr: GHC.TypeLits.Sing k_aHe n_aHf
        Actual enclosed expr: x_aqF
        Coercion used in cast: GHC.TypeLits.NTCo:SingI[0] <k_aKs> <n_aKt>
    *** Offending Program ***
    [...]

 GHC/TypeLits.hs |  120 ++++++++++++-------------------------------------------
 1 files changed, 26 insertions(+), 94 deletions(-)


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

    git show 216d59079cf33647d677b1314e693a49f9e515a8