Fix bogus check for strictness in newtypes

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

diff --git a/compiler/typecheck/TcTyClsDecls.lhs b/compiler/typecheck/TcTyClsDecls.lhs
index 34022db..ee847f5 100644 (file)
--- a/compiler/typecheck/TcTyClsDecls.lhs
+++ b/compiler/typecheck/TcTyClsDecls.lhs
@@ -133,7 +133,7 @@ tcTyAndClassDecls :: ModDetails -> [LTyClDecl Name]
                   -> TcM TcGblEnv      -- Input env extended by types and classes 
                                        -- and their implicit Ids,DataCons
 tcTyAndClassDecls boot_details allDecls
-  = do {       -- Omit instances of indexed types; they are handled together
+  = do {       -- Omit instances of type families; they are handled together
                -- with the *heads* of class instances
         ; let decls = filter (not . isFamInstDecl . unLoc) allDecls
 
@@ -239,9 +239,9 @@ tcFamInstDecl (L loc decl)
     recoverM (returnM Nothing)                 $
     setSrcSpan loc                             $
     tcAddDeclCtxt decl                         $
-    do { -- type families require -findexed-types and can't be in an
+    do { -- type families require -ftype-families and can't be in an
         -- hs-boot file
-       ; gla_exts <- doptM Opt_IndexedTypes
+       ; gla_exts <- doptM Opt_TypeFamilies
        ; is_boot  <- tcIsHsBoot          -- Are we compiling an hs-boot file?
        ; checkTc gla_exts      $ badFamInstDecl (tcdLName decl)
        ; checkTc (not is_boot) $ badBootFamInstDeclErr
@@ -280,8 +280,7 @@ tcFamInstDecl1 (decl@TyData {tcdND = new_or_data, tcdLName = L loc tc_name,
                             tcdCons = cons})
   = kcIdxTyPats decl $ \k_tvs k_typats resKind family ->
     do { -- check that the family declaration is for the right kind
-        unless (new_or_data == NewType  && isNewTyCon  family ||
-                new_or_data == DataType && isDataTyCon family) $
+        unless (isAlgTyCon family) $
           addErr (wrongKindOfFamily family)
 
        ; -- (1) kind check the data declaration as usual
@@ -393,7 +392,7 @@ So we must infer their kinds from their right-hand sides *first* and then
 use them, whereas for the mutually recursive data types D we bring into
 scope kind bindings D -> k, where k is a kind variable, and do inference.
 
-Indexed Types
+Type families
 ~~~~~~~~~~~~~
 This treatment of type synonyms only applies to Haskell 98-style synonyms.
 General type functions can be recursive, and hence, appear in `alg_decls'.
@@ -619,9 +618,9 @@ tcTyClDecl1 _calc_isrec
                                                      --     kind checking
   = tcTyVarBndrs tvs  $ \ tvs' -> do 
   { traceTc (text "type family: " <+> ppr tc_name) 
-  ; idx_tys <- doptM Opt_IndexedTypes
+  ; idx_tys <- doptM Opt_TypeFamilies
 
-       -- Check that we don't use families without -findexed-types
+       -- Check that we don't use families without -ftype-families
   ; checkTc idx_tys $ badFamInstDecl tc_name
 
   ; tycon <- buildSynTyCon tc_name tvs' (OpenSynTyCon kind Nothing) Nothing
@@ -630,23 +629,20 @@ tcTyClDecl1 _calc_isrec
 
   -- "newtype family" or "data family" declaration
 tcTyClDecl1 _calc_isrec 
-  (TyFamily {tcdFlavour = DataFamily new_or_data, 
+  (TyFamily {tcdFlavour = DataFamily, 
             tcdLName = L _ tc_name, tcdTyVars = tvs, tcdKind = mb_kind})
   = tcTyVarBndrs tvs  $ \ tvs' -> do 
-  { traceTc (text "data/newtype family: " <+> ppr tc_name) 
+  { traceTc (text "data family: " <+> ppr tc_name) 
   ; extra_tvs <- tcDataKindSig mb_kind
   ; let final_tvs = tvs' ++ extra_tvs    -- we may not need these
 
-  ; idx_tys <- doptM Opt_IndexedTypes
+  ; idx_tys <- doptM Opt_TypeFamilies
 
-       -- Check that we don't use families without -findexed-types
+       -- Check that we don't use families without -ftype-families
   ; checkTc idx_tys $ badFamInstDecl tc_name
 
   ; tycon <- buildAlgTyCon tc_name final_tvs [] 
-              (case new_or_data of
-                 DataType -> mkOpenDataTyConRhs
-                 NewType  -> mkOpenNewTyConRhs)
-              Recursive False True Nothing
+              mkOpenDataTyConRhs Recursive False True Nothing
   ; return [ATyCon tycon]
   }
 
@@ -1012,6 +1008,9 @@ checkNewDataCon con
                -- Return type is (T a b c)
        ; checkTc (null ex_tvs && null theta) (newtypeExError con)
                -- No existentials
+       ; checkTc (not (any isMarkedStrict (dataConStrictMarks con))) 
+                 (newtypeStrictError con)
+               -- No strictness
     }
   where
     (_univ_tvs, ex_tvs, eq_spec, theta, arg_tys, _res_ty) = dataConFullSig con
@@ -1156,6 +1155,10 @@ newtypeExError con
   = sep [ptext SLIT("A newtype constructor cannot have an existential context,"),
         nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does")]
 
+newtypeStrictError con
+  = sep [ptext SLIT("A newtype constructor cannot have a strictness annotation,"),
+        nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does")]
+
 newtypePredError con
   = sep [ptext SLIT("A newtype constructor must have a return type of form T a1 ... an"),
         nest 2 $ ptext SLIT("but") <+> quotes (ppr con) <+> ptext SLIT("does not")]
@@ -1172,7 +1175,7 @@ badSigTyDecl tc_name
 badFamInstDecl tc_name
   = vcat [ ptext SLIT("Illegal family instance for") <+>
           quotes (ppr tc_name)
-        , nest 2 (parens $ ptext SLIT("Use -findexed-types to allow indexed type families")) ]
+        , nest 2 (parens $ ptext SLIT("Use -ftype-families to allow indexed type families")) ]
 
 badGadtIdxTyDecl tc_name
   = vcat [ ptext SLIT("Illegal generalised algebraic data declaration for") <+>
@@ -1194,9 +1197,8 @@ wrongKindOfFamily family =
   ptext SLIT("Wrong category of family instance; declaration was for a") <+>
   kindOfFamily
   where
-    kindOfFamily | isSynTyCon  family = ptext SLIT("type synonym")
-                | isDataTyCon family = ptext SLIT("data type")
-                | isNewTyCon  family = ptext SLIT("newtype")
+    kindOfFamily | isSynTyCon family = ptext SLIT("type synonym")
+                | isAlgTyCon family = ptext SLIT("data type")
                 | otherwise = pprPanic "wrongKindOfFamily" (ppr family)
 
 emptyConDeclsErr tycon