Fix Trac #3245: memoising typeOf

[ghc-base.git] / Data / Data.hs

diff --git a/Data/Data.hs b/Data/Data.hs
index ef44933..646249e 100644 (file)
--- a/Data/Data.hs
+++ b/Data/Data.hs
@@ -114,7 +114,6 @@ import Data.Maybe
 import Control.Monad
 
 -- Imports for the instances
-import Data.Typeable
 import Data.Int              -- So we can give Data instance for Int8, ...
 import Data.Word             -- So we can give Data instance for Word8, ...
 #ifdef __GLASGOW_HASKELL__
@@ -640,7 +639,7 @@ readConstr dt str =
       case dataTypeRep dt of
         AlgRep cons -> idx cons
         IntRep      -> mkReadCon (\i -> (mkPrimCon dt str (IntConstr i)))
-        FloatRep    -> mkReadCon (\f -> (mkPrimCon dt str (FloatConstr f)))
+        FloatRep    -> mkReadCon ffloat
         CharRep     -> mkReadCon (\c -> (mkPrimCon dt str (CharConstr c)))
         NoRep       -> Nothing
   where
@@ -658,6 +657,8 @@ readConstr dt str =
                      then Nothing
                      else Just (head fit)
 
+    ffloat :: Double -> Constr
+    ffloat =  mkPrimCon dt str . FloatConstr . toRational
 
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 --