+ {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
+ ; checkTyVars tparms -- can have type pats
+ ; return $
+ L (comb4 $1 $2 $4 $5)
+ (mkTyData (unLoc $1) (ctxt, tc, tvs, Nothing)
+ (unLoc $3) (reverse (unLoc $5)) (unLoc $6)) } }
+
+ -- data/newtype family
+ | data_or_newtype 'family' tycl_hdr opt_kind_sig
+ {% do { let {(ctxt, tc, tvs, tparms) = unLoc $3}
+ ; checkTyVars tparms -- no type pattern
+ ; unless (null (unLoc ctxt)) $ -- and no context
+ parseError (getLoc ctxt)
+ "A family declaration cannot have a context"
+ ; return $
+ L (comb3 $1 $2 $4)
+ (TyFamily (DataFamily (unLoc $1)) tc tvs
+ (unLoc $4)) } }
+
+ -- data/newtype instance declaration
+ | data_or_newtype 'instance' tycl_hdr constrs deriving
+ {% do { let {(ctxt, tc, tvs, tparms) = unLoc $3}
+ -- can have type pats
+ ; return $
+ L (comb4 $1 $3 $4 $5)
+ -- We need the location on tycl_hdr in case
+ -- constrs and deriving are both empty
+ (mkTyData (unLoc $1) (ctxt, tc, tvs, Just tparms)
+ Nothing (reverse (unLoc $4)) (unLoc $5)) } }
+
+ -- GADT instance declaration
+ | data_or_newtype 'instance' tycl_hdr opt_kind_sig
+ 'where' gadt_constrlist
+ deriving
+ {% do { let {(ctxt, tc, tvs, tparms) = unLoc $3}
+ -- can have type pats
+ ; return $
+ L (comb4 $1 $3 $6 $7)
+ (mkTyData (unLoc $1) (ctxt, tc, tvs, Just tparms)
+ (unLoc $4) (reverse (unLoc $6)) (unLoc $7)) } }
+
+-- Associate type family declarations
+--
+-- * They have a different syntax than on the toplevel (no family special
+-- identifier).
+--
+-- * They also need to be separate from instances; otherwise, data family
+-- declarations without a kind signature cause parsing conflicts with empty
+-- data declarations.
+--
+at_decl_cls :: { LTyClDecl RdrName }
+ -- type family declarations
+ : 'type' type opt_kind_sig
+ -- Note the use of type for the head; this allows
+ -- infix type constructors to be declared
+ --
+ {% do { (tc, tvs, _) <- checkSynHdr $2 False
+ ; return (L (comb3 $1 $2 $3)
+ (TyFamily TypeFamily tc tvs (unLoc $3)))
+ } }
+
+ -- default type instance
+ | 'type' type '=' ctype
+ -- Note the use of type for the head; this allows
+ -- infix type constructors and type patterns
+ --
+ {% do { (tc, tvs, typats) <- checkSynHdr $2 True
+ ; return (L (comb2 $1 $4)
+ (TySynonym tc tvs (Just typats) $4))
+ } }
+
+ -- data/newtype family declaration
+ | data_or_newtype tycl_hdr opt_kind_sig
+ {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
+ ; checkTyVars tparms -- no type pattern
+ ; unless (null (unLoc ctxt)) $ -- and no context
+ parseError (getLoc ctxt)
+ "A family declaration cannot have a context"
+ ; return $
+ L (comb3 $1 $2 $3)
+ (TyFamily (DataFamily (unLoc $1)) tc tvs
+ (unLoc $3))
+ } }
+
+-- Associate type instances
+--
+at_decl_inst :: { LTyClDecl RdrName }
+ -- type instance declarations
+ : 'type' type '=' ctype
+ -- Note the use of type for the head; this allows
+ -- infix type constructors and type patterns
+ --
+ {% do { (tc, tvs, typats) <- checkSynHdr $2 True
+ ; return (L (comb2 $1 $4)
+ (TySynonym tc tvs (Just typats) $4))
+ } }
+
+ -- data/newtype instance declaration
+ | data_or_newtype tycl_hdr constrs deriving
+ {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
+ -- can have type pats
+ ; return $
+ L (comb4 $1 $2 $3 $4)
+ -- We need the location on tycl_hdr in case
+ -- constrs and deriving are both empty
+ (mkTyData (unLoc $1) (ctxt, tc, tvs, Just tparms)
+ Nothing (reverse (unLoc $3)) (unLoc $4)) } }
+
+ -- GADT instance declaration
+ | data_or_newtype tycl_hdr opt_kind_sig
+ 'where' gadt_constrlist
+ deriving
+ {% do { let {(ctxt, tc, tvs, tparms) = unLoc $2}
+ -- can have type pats
+ ; return $
+ L (comb4 $1 $2 $5 $6)
+ (mkTyData (unLoc $1) (ctxt, tc, tvs, Just tparms)
+ (unLoc $3) (reverse (unLoc $5)) (unLoc $6)) } }