X-Git-Url: http://git.megacz.com/?p=ghc-hetmet.git;a=blobdiff_plain;f=compiler%2Fparser%2FRdrHsSyn.lhs;fp=compiler%2Fparser%2FRdrHsSyn.lhs;h=0e265e9aa9a19b2b424b7702fa1bb156118c6f06;hp=49036d97c1414c1e46da016b2cc0f7eaf2db6f79;hb=b2524b3960999fffdb3767900f58825903f6560f;hpb=841e81e28f8cc711f624fdca122219a5bbde2fae

diff --git a/compiler/parser/RdrHsSyn.lhs b/compiler/parser/RdrHsSyn.lhs
index 49036d9..0e265e9 100644
--- a/compiler/parser/RdrHsSyn.lhs
+++ b/compiler/parser/RdrHsSyn.lhs
@@ -40,8 +40,7 @@ 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
 	checkDoAndIfThenElse,
@@ -54,6 +53,7 @@ import Class            ( FunDep )
 import TypeRep          ( Kind )
 import RdrName		( RdrName, isRdrTyVar, isRdrTc, mkUnqual, rdrNameOcc, 
 			  isRdrDataCon, isUnqual, getRdrName, setRdrNameSpace )
+import Name             ( Name )
 import BasicTypes	( maxPrecedence, Activation(..), RuleMatchInfo,
                           InlinePragma(..), InlineSpec(..) )
 import Lexer
@@ -128,7 +128,6 @@ 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
@@ -153,8 +152,7 @@ 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}
 
 
@@ -612,34 +610,6 @@ 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 +704,6 @@ 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
@@ -816,17 +784,20 @@ 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
@@ -916,6 +887,20 @@ isFunLhs e = go e []
 		 _ -> return Nothing }
    go _ _ = return Nothing
 
+
+---------------------------------------------------------------------------
+-- Check for monad comprehensions
+--
+-- If the flag MonadComprehensions is set, return a `MonadComp' context,
+-- otherwise use the usual `ListComp' context
+
+checkMonadComp :: P (HsStmtContext Name)
+checkMonadComp = do
+    pState <- getPState
+    return $ if xopt Opt_MonadComprehensions (dflags pState)
+                then MonadComp
+                else ListComp
+
 ---------------------------------------------------------------------------
 -- Miscellaneous utilities