X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FbasicTypes%2FBasicTypes.lhs;h=7ea66e1db2bf722a704c66f5c26e72c1e0e2d035;hp=a76ee64a80ae6a491b03458744f8b2cdad6e32ea;hb=f8f0e76ad302fda30196ebc9230e5fcbc97be537;hpb=3391a03562d4056de7b16cd0f632e6c43ae44cca

diff --git a/compiler/basicTypes/BasicTypes.lhs b/compiler/basicTypes/BasicTypes.lhs
index a76ee64..7ea66e1 100644
--- a/compiler/basicTypes/BasicTypes.lhs
+++ b/compiler/basicTypes/BasicTypes.lhs
@@ -74,7 +74,7 @@ module BasicTypes(
 
 	SuccessFlag(..), succeeded, failed, successIf,
 	
-	FractionalLit(..)
+	FractionalLit(..), negateFractionalLit, integralFractionalLit
    ) where
 
 import FastString
@@ -868,15 +868,23 @@ isEarlyActive _		        = False
 
 
 \begin{code}
--- Used to represent exactly the floating point literal that we encountered in
--- the user's source program. This allows us to pretty-print exactly what the user
--- wrote, which is important e.g. for floating point numbers that can't represented
+-- Used (instead of Rational) to represent exactly the floating point literal that we
+-- encountered in the user's source program. This allows us to pretty-print exactly what
+-- the user wrote, which is important e.g. for floating point numbers that can't represented
 -- as Doubles (we used to via Double for pretty-printing). See also #2245.
 data FractionalLit
   = FL { fl_text :: String         -- How the value was written in the source
        , fl_value :: Rational      -- Numeric value of the literal
        }
-  deriving (Data, Typeable)
+  deriving (Data, Typeable, Show)
+  -- The Show instance is required for the derived Lexer.x:Token instance when DEBUG is on
+
+negateFractionalLit :: FractionalLit -> FractionalLit
+negateFractionalLit (FL { fl_text = '-':text, fl_value = value }) = FL { fl_text = text, fl_value = negate value }
+negateFractionalLit (FL { fl_text = text, fl_value = value }) = FL { fl_text = '-':text, fl_value = negate value }
+
+integralFractionalLit :: Integer -> FractionalLit
+integralFractionalLit i = FL { fl_text = show i, fl_value = fromInteger i }
 
 -- Comparison operations are needed when grouping literals
 -- for compiling pattern-matching (module MatchLit)
@@ -886,4 +894,7 @@ instance Eq FractionalLit where
 
 instance Ord FractionalLit where
   compare = compare `on` fl_value
+
+instance Outputable FractionalLit where
+  ppr = text . fl_text
 \end{code}