Fix Trac #2246; overhaul handling of overloaded literals

[ghc-hetmet.git] / compiler / rename / RnPat.lhs

diff --git a/compiler/rename/RnPat.lhs b/compiler/rename/RnPat.lhs
index 061df0a..55155d7 100644 (file)
--- a/compiler/rename/RnPat.lhs
+++ b/compiler/rename/RnPat.lhs
@@ -41,6 +41,7 @@ import {-# SOURCE #-} TcSplice ( runQuasiQuotePat )
 
 import HsSyn            
 import TcRnMonad
+import TcHsSyn         ( hsOverLitName )
 import RnEnv
 import RnTypes
 import DynFlags                ( DynFlag(..) )
@@ -53,7 +54,7 @@ import ListSetOps     ( removeDups, minusList )
 import Outputable
 import SrcLoc
 import FastString
-import Literal         ( inIntRange, inCharRange )
+import Literal         ( inCharRange )
 \end{code}
 
 
@@ -506,38 +507,39 @@ rnLit (HsChar c) = checkErr (inCharRange c) (bogusCharError c)
 rnLit _ = return ()
 
 rnOverLit :: HsOverLit t -> RnM (HsOverLit Name, FreeVars)
-rnOverLit (HsIntegral i _ _) = do
-    (from_integer_name, fvs) <- lookupSyntaxName fromIntegerName
-    if inIntRange i then
-        return (HsIntegral i from_integer_name placeHolderType, fvs)
-     else let
-       extra_fvs = mkFVs [plusIntegerName, timesIntegerName]
-       -- Big integer literals are built, using + and *, 
-       -- out of small integers (DsUtils.mkIntegerLit)
-       -- [NB: plusInteger, timesInteger aren't rebindable... 
-       --      they are used to construct the argument to fromInteger, 
-       --      which is the rebindable one.]
-        in
-        return (HsIntegral i from_integer_name placeHolderType, fvs `plusFV` extra_fvs)
-
-rnOverLit (HsFractional i _ _) = do
-    (from_rat_name, fvs) <- lookupSyntaxName fromRationalName
-    let
-       extra_fvs = mkFVs [ratioDataConName, plusIntegerName, timesIntegerName]
-       -- We have to make sure that the Ratio type is imported with
-       -- its constructor, because literals of type Ratio t are
-       -- built with that constructor.
-       -- The Rational type is needed too, but that will come in
-       -- as part of the type for fromRational.
-       -- The plus/times integer operations may be needed to construct the numerator
-       -- and denominator (see DsUtils.mkIntegerLit)
-    return (HsFractional i from_rat_name placeHolderType, fvs `plusFV` extra_fvs)
-
-rnOverLit (HsIsString s _ _) = do
-    (from_string_name, fvs) <- lookupSyntaxName fromStringName
-    return (HsIsString s from_string_name placeHolderType, fvs)
+rnOverLit lit@(OverLit {ol_val=val})
+  = do { let std_name = hsOverLitName val
+       ; (from_thing_name, fvs) <- lookupSyntaxName std_name
+       ; let rebindable = case from_thing_name of
+                               HsVar v -> v /= std_name
+                               _       -> panic "rnOverLit"
+       ; return (lit { ol_witness = from_thing_name
+                     , ol_rebindable = rebindable }, fvs) }
 \end{code}
 
+----------------------------------------------------------------
+-- Old code returned extra free vars need in desugarer
+-- but that is no longer necessary, I believe
+--     if inIntRange i then
+--        return (HsIntegral i from_integer_name placeHolderType, fvs)
+--     else let
+--     extra_fvs = mkFVs [plusIntegerName, timesIntegerName]
+-- Big integer literals are built, using + and *, 
+-- out of small integers (DsUtils.mkIntegerLit)
+-- [NB: plusInteger, timesInteger aren't rebindable... 
+--     they are used to construct the argument to fromInteger, 
+--     which is the rebindable one.]
+
+-- (HsFractional i _ _) = do
+--     extra_fvs = mkFVs [ratioDataConName, plusIntegerName, timesIntegerName]
+-- We have to make sure that the Ratio type is imported with
+-- its constructor, because literals of type Ratio t are
+-- built with that constructor.
+-- The Rational type is needed too, but that will come in
+-- as part of the type for fromRational.
+-- The plus/times integer operations may be needed to construct the numerator
+-- and denominator (see DsUtils.mkIntegerLit)
+
 %************************************************************************
 %*                                                                     *
 \subsubsection{Quasiquotation}