[project @ 2005-03-15 11:59:32 by ross]

[ghc-hetmet.git] / ghc / compiler / hsSyn / HsDecls.lhs

diff --git a/ghc/compiler/hsSyn/HsDecls.lhs b/ghc/compiler/hsSyn/HsDecls.lhs
index 3a61002..981c70a 100644 (file)
--- a/ghc/compiler/hsSyn/HsDecls.lhs
+++ b/ghc/compiler/hsSyn/HsDecls.lhs
@@ -14,9 +14,7 @@ module HsDecls (
        DefaultDecl(..), LDefaultDecl, HsGroup(..), SpliceDecl(..),
        ForeignDecl(..), LForeignDecl, ForeignImport(..), ForeignExport(..),
        CImportSpec(..), FoType(..),
-       ConDecl(..), LConDecl,
-       LBangType, BangType(..), HsBang(..), 
-       getBangType, getBangStrictness, unbangedType, 
+       ConDecl(..), LConDecl,  
        DeprecDecl(..),  LDeprecDecl,
        tcdName, tyClDeclNames, tyClDeclTyVars,
        isClassDecl, isSynDecl, isDataDecl, 
@@ -38,6 +36,7 @@ import HsImpExp               ( pprHsVar )
 import HsTypes
 import HscTypes                ( DeprecTxt )
 import CoreSyn         ( RuleName )
+import Kind            ( Kind, pprKind )
 import BasicTypes      ( Activation(..) )
 import ForeignCall     ( CCallTarget(..), DNCallSpec, CCallConv, Safety,
                          CExportSpec(..), CLabelString ) 
@@ -304,7 +303,13 @@ data TyClDecl name
                tcdCtxt   :: LHsContext name,           -- Context
                tcdLName  :: Located name,              -- Type constructor
                tcdTyVars :: [LHsTyVarBndr name],       -- Type variables
+               tcdKindSig :: Maybe Kind,               -- Optional kind sig; 
+                                                       -- (only for the 'where' form)
+
                tcdCons   :: [LConDecl name],           -- Data constructors
+                       -- For data T a = T1 | T2 a          the LConDecls are all ConDecls
+                       -- For data T a where { T1 :: T a }  the LConDecls are all GadtDecls
+
                tcdDerivs :: Maybe [LHsType name]
                        -- Derivings; Nothing => not specified
                        --            Just [] => derive exactly what is asked
@@ -403,11 +408,14 @@ instance OutputableBndr name
             4 (ppr mono_ty)
 
     ppr (TyData {tcdND = new_or_data, tcdCtxt = context, tcdLName = ltycon,
-                tcdTyVars = tyvars, tcdCons = condecls, 
+                tcdTyVars = tyvars, tcdKindSig = mb_sig, tcdCons = condecls, 
                 tcdDerivs = derivings})
-      = pp_tydecl (ppr new_or_data <+> pp_decl_head (unLoc context) ltycon tyvars)
+      = pp_tydecl (ppr new_or_data <+> pp_decl_head (unLoc context) ltycon tyvars <+> ppr_sig mb_sig)
                  (pp_condecls condecls)
                  derivings
+      where
+       ppr_sig Nothing = empty
+       ppr_sig (Just kind) = dcolon <+> pprKind kind
 
     ppr (ClassDecl {tcdCtxt = context, tcdLName = lclas, tcdTyVars = tyvars, tcdFDs = fds,
                    tcdSigs = sigs, tcdMeths = methods})
@@ -429,7 +437,10 @@ pp_decl_head :: OutputableBndr name
 pp_decl_head context thing tyvars
   = hsep [pprHsContext context, ppr thing, interppSP tyvars]
 
-pp_condecls cs = equals <+> sep (punctuate (ptext SLIT(" |")) (map ppr cs))
+pp_condecls cs@(L _ (GadtDecl _ _) : _) -- In GADT syntax
+  = hang (ptext SLIT("where")) 2 (vcat (map ppr cs))
+pp_condecls cs                           -- In H98 syntax
+  = equals <+> sep (punctuate (ptext SLIT(" |")) (map ppr cs))
 
 pp_tydecl pp_head pp_decl_rhs derivings
   = hang pp_head 4 (sep [
@@ -461,8 +472,12 @@ data ConDecl name
                [LHsTyVarBndr name]     -- Existentially quantified type variables
                (LHsContext name)       -- ...and context
                                        -- If both are empty then there are no existentials
-
                (HsConDetails name (LBangType name))
+
+  | GadtDecl    (Located name)          -- Constructor name; this is used for the
+                                       -- DataCon itself, and for the user-callable wrapper Id
+                (LHsType name)          -- Constructor type; it may have HsBangs on the 
+                                       -- argument types
 \end{code}
 
 \begin{code}
@@ -481,32 +496,23 @@ conDeclsNames cons
     do_one (flds_seen, acc) (ConDecl lname _ _ _)
        = (flds_seen, lname:acc)
 
+-- gaw 2004
+    do_one (flds_seen, acc) (GadtDecl lname _)
+       = (flds_seen, lname:acc)
+
 conDetailsTys details = map getBangType (hsConArgs details)
 \end{code}
   
-\begin{code}
-type LBangType name = Located (BangType name)
-
-data BangType name = BangType HsBang (LHsType name)
-
-data HsBang = HsNoBang
-           | HsStrict  -- ! 
-           | HsUnbox   -- {-# UNPACK #-} ! (GHC extension, meaning "unbox")
-
-getBangType       (BangType _ ty) = ty
-getBangStrictness (BangType s _)  = s
-
-unbangedType :: LHsType id -> LBangType id
-unbangedType ty@(L loc _) = L loc (BangType HsNoBang ty)
-\end{code}
 
 \begin{code}
 instance (OutputableBndr name) => Outputable (ConDecl name) where
     ppr (ConDecl con tvs cxt con_details)
       = sep [pprHsForAll Explicit tvs cxt, ppr_con_details con con_details]
+    ppr (GadtDecl con ty)
+      = ppr con <+> dcolon <+> ppr ty
 
 ppr_con_details con (InfixCon ty1 ty2)
-  = hsep [ppr ty1, ppr con, ppr ty2]
+  = hsep [ppr ty1, pprHsVar con, ppr ty2]
 
 -- ConDecls generated by MkIface.ifaceTyThing always have a PrefixCon, even
 -- if the constructor is an infix one.  This is because in an interface file
@@ -520,17 +526,8 @@ ppr_con_details con (RecCon fields)
   where
     ppr_field (n, ty) = ppr n <+> dcolon <+> ppr ty
 
-instance OutputableBndr name => Outputable (BangType name) where
-    ppr (BangType is_strict ty) 
-       = bang <> pprParendHsType (unLoc ty)
-       where
-         bang = case is_strict of
-                       HsNoBang -> empty
-                       HsStrict -> char '!'
-                       HsUnbox  -> ptext SLIT("!!")
 \end{code}
 
-
 %************************************************************************
 %*                                                                     *
 \subsection[InstDecl]{An instance declaration