Merge branch 'master' of http://darcs.haskell.org/ghc into ghc-generics

[ghc-hetmet.git] / compiler / parser / RdrHsSyn.lhs

diff --git a/compiler/parser/RdrHsSyn.lhs b/compiler/parser/RdrHsSyn.lhs
index 0e22c69..a943344 100644 (file)
--- a/compiler/parser/RdrHsSyn.lhs
+++ b/compiler/parser/RdrHsSyn.lhs
@@ -40,8 +40,6 @@ module RdrHsSyn (
        checkPattern,         -- HsExp -> P HsPat
        bang_RDR,
        checkPatterns,        -- SrcLoc -> [HsExp] -> P [HsPat]
-       checkDo,              -- [Stmt] -> P [Stmt]
-       checkMDo,             -- [Stmt] -> P [Stmt]
        checkMonadComp,       -- P (HsStmtContext RdrName)
        checkValDef,          -- (SrcLoc, HsExp, HsRhs, [HsDecl]) -> P HsDecl
        checkValSig,          -- (SrcLoc, HsExp, HsRhs, [HsDecl]) -> P HsDecl
@@ -129,7 +127,6 @@ extract_lty (L loc ty) acc
       HsPredTy p               -> extract_pred p acc
       HsOpTy ty1 (L loc tv) ty2 -> extract_tv loc tv (extract_lty ty1 (extract_lty ty2 acc))
       HsParTy ty                       -> extract_lty ty acc
-      HsNumTy {}                -> acc
       HsCoreTy {}               -> acc  -- The type is closed
       HsQuasiQuoteTy {}                -> acc  -- Quasi quotes mention no type variables
       HsSpliceTy {}            -> acc  -- Type splices mention no type variables
@@ -154,8 +151,7 @@ extractGenericPatTyVars binds
     get (L _ (FunBind { fun_matches = MatchGroup ms _ })) acc = foldr (get_m.unLoc) acc ms
     get _                                                 acc = acc
 
-    get_m (Match (L _ (TypePat ty) : _) _ _) acc = extract_lty ty acc
-    get_m _                                        acc = acc
+    get_m _ acc = acc
 \end{code}
 
 
@@ -613,34 +609,6 @@ checkPred (L spn ty)
     check loc _                        _    = parseErrorSDoc loc
                                 (text "malformed class assertion:" <+> ppr ty)
 
----------------------------------------------------------------------------
--- Checking statements in a do-expression
---     We parse   do { e1 ; e2 ; }
---     as [ExprStmt e1, ExprStmt e2]
--- checkDo (a) checks that the last thing is an ExprStmt
---        (b) returns it separately
--- same comments apply for mdo as well
-
-checkDo, checkMDo :: SrcSpan -> [LStmt RdrName] -> P ([LStmt RdrName], LHsExpr RdrName)
-
-checkDo         = checkDoMDo "a " "'do'"
-checkMDo = checkDoMDo "an " "'mdo'"
-
-checkDoMDo :: String -> String -> SrcSpan -> [LStmt RdrName] -> P ([LStmt RdrName], LHsExpr RdrName)
-checkDoMDo _   nm loc []   = parseErrorSDoc loc (text ("Empty " ++ nm ++ " construct"))
-checkDoMDo pre nm _   ss   = do
-  check ss
-  where 
-       check  []                       = panic "RdrHsSyn:checkDoMDo"
-       check  [L _ (ExprStmt e _ _ _)] = return ([], e)
-       check  [L l e] = parseErrorSDoc l
-                         (text ("The last statement in " ++ pre ++ nm ++
-                                                   " construct must be an expression:")
-                       $$ ppr e)
-       check (s:ss) = do
-         (ss',e') <-  check ss
-         return ((s:ss'),e')
-
 -- -------------------------------------------------------------------------
 -- Checking Patterns.
 
@@ -734,8 +702,6 @@ checkAPat dynflags loc e0 = case e0 of
                       -> do fs <- mapM checkPatField fs
                             return (ConPatIn c (RecCon (HsRecFields fs dd)))
    HsQuasiQuoteE q    -> return (QuasiQuotePat q)
--- Generics 
-   HsType ty          -> return (TypePat ty) 
    _                  -> patFail loc e0
 
 placeHolderPunRhs :: LHsExpr RdrName
@@ -814,17 +780,20 @@ checkValSig lhs@(L l _) ty
                        ppr lhs <+> text "::" <+> ppr ty)
                    $$ text hint)
   where
-    hint = if looks_like_foreign lhs
+    hint = if foreign_RDR `looks_like` lhs
            then "Perhaps you meant to use -XForeignFunctionInterface?"
-           else "Should be of form <variable> :: <type>"
+           else if default_RDR `looks_like` lhs
+                then "Perhaps you meant to use -XDefaultSignatures?"
+                else "Should be of form <variable> :: <type>"
     -- A common error is to forget the ForeignFunctionInterface flag
     -- so check for that, and suggest.  cf Trac #3805
     -- Sadly 'foreign import' still barfs 'parse error' because 'import' is a keyword
-    looks_like_foreign (L _ (HsVar v))     = v == foreign_RDR
-    looks_like_foreign (L _ (HsApp lhs _)) = looks_like_foreign lhs
-    looks_like_foreign _                   = False
+    looks_like s (L _ (HsVar v))     = v == s
+    looks_like s (L _ (HsApp lhs _)) = looks_like s lhs
+    looks_like _ _                   = False
 
     foreign_RDR = mkUnqual varName (fsLit "foreign")
+    default_RDR = mkUnqual varName (fsLit "default")
 
 checkDoAndIfThenElse :: LHsExpr RdrName
                      -> Bool