X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2FhsSyn%2FHsLit.lhs;h=def1e352db337d5fec2321d870310577ef886c04;hp=bd125106e2d0e1c7177021d52d1a333bb050b5b0;hb=3391a03562d4056de7b16cd0f632e6c43ae44cca;hpb=ecdaf6bc29d23bd704df8c65442ee08032a585fc

diff --git a/compiler/hsSyn/HsLit.lhs b/compiler/hsSyn/HsLit.lhs
index bd12510..def1e35 100644
--- a/compiler/hsSyn/HsLit.lhs
+++ b/compiler/hsSyn/HsLit.lhs
@@ -5,16 +5,20 @@
 \section[HsLit]{Abstract syntax: source-language literals}
 
 \begin{code}
+{-# LANGUAGE DeriveDataTypeable #-}
+
 module HsLit where
 
 #include "HsVersions.h"
 
 import {-# SOURCE #-} HsExpr( SyntaxExpr, pprExpr )
-import HsTypes (PostTcType)
+import BasicTypes ( FractionalLit(..) )
+import HsTypes  ( PostTcType )
 import Type	( Type )
 import Outputable
 import FastString
-import Ratio	( Rational )
+
+import Data.Data
 \end{code}
 
 
@@ -41,6 +45,7 @@ data HsLit
 					-- 	(overloaded literals are done with HsOverLit)
   | HsFloatPrim	    Rational		-- Unboxed Float
   | HsDoublePrim    Rational		-- Unboxed Double
+  deriving (Data, Typeable)
 
 instance Eq HsLit where
   (HsChar x1)	    == (HsChar x2)	 = x1==x2
@@ -59,20 +64,34 @@ instance Eq HsLit where
 data HsOverLit id 	-- An overloaded literal
   = OverLit {
 	ol_val :: OverLitVal, 
-	ol_rebindable :: Bool,		-- True <=> rebindable syntax
-					-- False <=> standard syntax
+	ol_rebindable :: Bool,		-- Note [ol_rebindable]
 	ol_witness :: SyntaxExpr id,	-- Note [Overloaded literal witnesses]
 	ol_type :: PostTcType }
+  deriving (Data, Typeable)
 
 data OverLitVal
   = HsIntegral   !Integer   	-- Integer-looking literals;
-  | HsFractional !Rational   	-- Frac-looking literals
+  | HsFractional !FractionalLit	-- Frac-looking literals
   | HsIsString   !FastString 	-- String-looking literals
+  deriving (Data, Typeable)
 
 overLitType :: HsOverLit a -> Type
 overLitType = ol_type
 \end{code}
 
+Note [ol_rebindable]
+~~~~~~~~~~~~~~~~~~~~
+The ol_rebindable field is True if this literal is actually 
+using rebindable syntax.  Specifically:
+
+  False iff ol_witness is the standard one
+  True  iff ol_witness is non-standard
+
+Equivalently it's True if
+  a) RebindableSyntax is on
+  b) the witness for fromInteger/fromRational/fromString
+     that happens to be in scope isn't the standard one
+
 Note [Overloaded literal witnesses]
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 *Before* type checking, the SyntaxExpr in an HsOverLit is the
@@ -83,7 +102,7 @@ This witness should replace the literal.
 
 This dual role is unusual, because we're replacing 'fromInteger' with 
 a call to fromInteger.  Reason: it allows commoning up of the fromInteger
-calls, which wouldn't be possible if the desguarar made the application
+calls, which wouldn't be possible if the desguarar made the application.
 
 The PostTcType in each branch records the type the overload literal is
 found to have.
@@ -137,6 +156,6 @@ instance OutputableBndr id => Outputable (HsOverLit id) where
 
 instance Outputable OverLitVal where
   ppr (HsIntegral i)   = integer i 
-  ppr (HsFractional f) = rational f
+  ppr (HsFractional f) = text (fl_text f)
   ppr (HsIsString s)   = pprHsString s
 \end{code}