X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=compiler%2Frename%2FRnEnv.lhs;h=c4ad95a333dff71a461e960bd617a8af6e1b741c;hb=fed25228aec3f3bd2f91c50d67043d83efb1af18;hp=97f4ab3938d6bee2975ec1e7bbf6e5a9688ccc76;hpb=820ddd55446773b33c797267bcad9e09a621ab2b;p=ghc-hetmet.git

diff --git a/compiler/rename/RnEnv.lhs b/compiler/rename/RnEnv.lhs
index 97f4ab3..c4ad95a 100644
--- a/compiler/rename/RnEnv.lhs
+++ b/compiler/rename/RnEnv.lhs
@@ -12,7 +12,7 @@ module RnEnv (
 	lookupLocalDataTcNames, lookupSigOccRn,
 	lookupFixityRn, lookupTyFixityRn, 
 	lookupInstDeclBndr, lookupSubBndr, lookupConstructorFields,
-	lookupSyntaxName, lookupSyntaxTable, 
+	lookupSyntaxName, lookupSyntaxTable, lookupIfThenElse,
 	lookupGreRn, lookupGreLocalRn, lookupGreRn_maybe,
 	getLookupOccRn, addUsedRdrNames,
 
@@ -754,6 +754,17 @@ We treat the orignal (standard) names as free-vars too, because the type checker
 checks the type of the user thing against the type of the standard thing.
 
 \begin{code}
+lookupIfThenElse :: RnM (Maybe (SyntaxExpr Name), FreeVars)
+-- Different to lookupSyntaxName because in the non-rebindable
+-- case we desugar directly rather than calling an existing function
+-- Hence the (Maybe (SyntaxExpr Name)) return type
+lookupIfThenElse 
+  = do { rebind <- xoptM Opt_RebindableSyntax
+       ; if not rebind 
+         then return (Nothing, emptyFVs)
+         else do { ite <- lookupOccRn (mkVarUnqual (fsLit "ifThenElse"))
+                 ; return (Just (HsVar ite), unitFV ite) } }
+
 lookupSyntaxName :: Name 				-- The standard name
 	         -> RnM (SyntaxExpr Name, FreeVars)	-- Possibly a non-standard name
 lookupSyntaxName std_name