Record the original text along with parsed Rationals: fixes #2245

[ghc-hetmet.git] / compiler / hsSyn / HsLit.lhs

diff --git a/compiler/hsSyn/HsLit.lhs b/compiler/hsSyn/HsLit.lhs
index bd12510..def1e35 100644 (file)
--- a/compiler/hsSyn/HsLit.lhs
+++ b/compiler/hsSyn/HsLit.lhs
@@ -5,16 +5,20 @@
 \section[HsLit]{Abstract syntax: source-language literals}
 
 \begin{code}
 \section[HsLit]{Abstract syntax: source-language literals}
 
 \begin{code}

+{-# LANGUAGE DeriveDataTypeable #-}
+

 module HsLit where
 
 #include "HsVersions.h"
 
 import {-# SOURCE #-} HsExpr( SyntaxExpr, pprExpr )
 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 Type    ( Type )
 import Outputable
 import FastString

-import Ratio   ( Rational )
+
+import Data.Data

 \end{code}
 
 
 \end{code}
 
 

@@ -41,6 +45,7 @@ data HsLit
                                        --      (overloaded literals are done with HsOverLit)
   | HsFloatPrim            Rational            -- Unboxed Float
   | HsDoublePrim    Rational           -- Unboxed Double
                                        --      (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
 
 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, 
 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 }
        ol_witness :: SyntaxExpr id,    -- Note [Overloaded literal witnesses]
        ol_type :: PostTcType }

+  deriving (Data, Typeable)

 
 data OverLitVal
   = HsIntegral   !Integer      -- Integer-looking literals;
 
 data OverLitVal
   = HsIntegral   !Integer      -- Integer-looking literals;

-  | HsFractional !Rational     -- Frac-looking literals
+  | HsFractional !FractionalLit        -- Frac-looking literals

   | HsIsString   !FastString   -- String-looking literals
   | HsIsString   !FastString   -- String-looking literals

+  deriving (Data, Typeable)

 
 overLitType :: HsOverLit a -> Type
 overLitType = ol_type
 \end{code}
 
 
 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
 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
 
 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.
 
 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 
 
 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}
   ppr (HsIsString s)   = pprHsString s
 \end{code}