Fix Trac #745: improve error recoevery for type signatures

[ghc-hetmet.git] / compiler / typecheck / TcTyClsDecls.lhs

diff --git a/compiler/typecheck/TcTyClsDecls.lhs b/compiler/typecheck/TcTyClsDecls.lhs
index c959233..5a2f773 100644 (file)
--- a/compiler/typecheck/TcTyClsDecls.lhs
+++ b/compiler/typecheck/TcTyClsDecls.lhs
@@ -244,10 +244,9 @@ lot of kinding and type checking code with ordinary algebraic data types (and
 GADTs).
 
 \begin{code}
-tcFamInstDecl :: LTyClDecl Name -> TcM (Maybe TyThing)   -- Nothing if error
+tcFamInstDecl :: LTyClDecl Name -> TcM TyThing
 tcFamInstDecl (L loc decl)
   =    -- Prime error recovery, set source location
-    recoverM (return Nothing)                  $
     setSrcSpan loc                             $
     tcAddDeclCtxt decl                         $
     do { -- type families require -XTypeFamilies and can't be in an
@@ -261,8 +260,7 @@ tcFamInstDecl (L loc decl)
        ; tc <- tcFamInstDecl1 decl
        ; checkValidTyCon tc    -- Remember to check validity;
                                -- no recursion to worry about here
-       ; return (Just (ATyCon tc))
-       }
+       ; return (ATyCon tc) }
 
 tcFamInstDecl1 :: TyClDecl Name -> TcM TyCon
 
@@ -1076,10 +1074,10 @@ checkValidDataCon tc con
   = setSrcSpan (srcLocSpan (getSrcLoc con))    $
     addErrCtxt (dataConCtxt con)               $ 
     do { checkTc (dataConTyCon con == tc) (badDataConTyCon con)
-       ; checkValidType ctxt (dataConUserType con)
        ; checkValidMonoType (dataConOrigResTy con)
                -- Disallow MkT :: T (forall a. a->a)
                -- Reason: it's really the argument of an equality constraint
+       ; checkValidType ctxt (dataConUserType con)
        ; when (isNewTyCon tc) (checkNewDataCon con)
     }
   where