[commit: ghc] master: Revert "Restore invariant in `Data (Ratio a)` instance" (22c4d60)

[git at git.haskell.org]

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

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/22c4d60b0665a15535c0ec9fe0b8e65d2c948e7d/ghc

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

commit 22c4d60b0665a15535c0ec9fe0b8e65d2c948e7d
Author: Herbert Valerio Riedel <hvr at gnu.org>
Date:   Wed Jan 21 22:13:07 2015 +0100

    Revert "Restore invariant in `Data (Ratio a)` instance"
    
    This reverts commit 79b0d0e633af8302d2dd907663a4a231cd889b67
    due to
    
      Compile failed (status 256) errors were:
      [1 of 2] Compiling A                ( A.hs, A.o )
      [2 of 2] Compiling Main             ( T4491.hs, T4491.o )
      T4491.hs:19:11:
        Illegal data constructor name: ‘%’
        When splicing a TH expression: (GHC.Real.%) 11 2
        In the splice: $(dataToExpQ (const Nothing) (5.5 :: Rational))
      *** unexpected failure for T4491(normal)
    
    Therefore re-opening #10011


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22c4d60b0665a15535c0ec9fe0b8e65d2c948e7d
 libraries/base/Data/Data.hs | 8 ++++----
 libraries/base/changelog.md | 2 --
 2 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/libraries/base/Data/Data.hs b/libraries/base/Data/Data.hs
index 4a6c8be..dce610b 100644
--- a/libraries/base/Data/Data.hs
+++ b/libraries/base/Data/Data.hs
@@ -1059,15 +1059,15 @@ instance Data Word64 where
 ------------------------------------------------------------------------------
 
 ratioConstr :: Constr
-ratioConstr = mkConstr ratioDataType "%" [] Infix
+ratioConstr = mkConstr ratioDataType ":%" [] Infix
 
 ratioDataType :: DataType
 ratioDataType = mkDataType "GHC.Real.Ratio" [ratioConstr]
 
-instance (Data a, Integral a) => Data (Ratio a) where
-  gfoldl k z (a :% b) = z (%) `k` a `k` b
+instance Data a => Data (Ratio a) where
+  gfoldl k z (a :% b) = z (:%) `k` a `k` b
   toConstr _ = ratioConstr
-  gunfold k z c | constrIndex c == 1 = k (k (z (%)))
+  gunfold k z c | constrIndex c == 1 = k (k (z (:%)))
   gunfold _ _ _ = error "Data.Data.gunfold(Ratio)"
   dataTypeOf _  = ratioDataType
 
diff --git a/libraries/base/changelog.md b/libraries/base/changelog.md
index 0d7ebcf..83ae5e4 100644
--- a/libraries/base/changelog.md
+++ b/libraries/base/changelog.md
@@ -140,8 +140,6 @@
 
   * Add `callocArray` and `callocArray0` to `Foreign.Marshal.Array`. (#9859)
 
-  * Restore invariant in `Data (Ratio a)` instance (#10011)
-
 ## 4.7.0.2  *Dec 2014*
 
   * Bundled with GHC 7.8.4