+-- | Create VHDL type for a custom tycon
+mk_tycon_ty :: TyCon.TyCon -> [Type.Type] -> VHDLState (Maybe (AST.TypeMark, AST.TypeDef))
+mk_tycon_ty tycon args =
+ case TyCon.tyConDataCons tycon of
+ -- Not an algebraic type
+ [] -> error $ "Only custom algebraic types are supported: " ++ (showSDoc $ ppr tycon)
+ [dc] -> do
+ let arg_tys = DataCon.dataConRepArgTys dc
+ -- TODO: CoreSubst docs say each Subs can be applied only once. Is this a
+ -- violation? Or does it only mean not to apply it again to the same
+ -- subject?
+ let real_arg_tys = map (CoreSubst.substTy subst) arg_tys
+ elem_tys <- mapM vhdl_ty real_arg_tys
+ let elems = zipWith AST.ElementDec recordlabels elem_tys
+ -- For a single construct datatype, build a record with one field for
+ -- each argument.
+ -- TODO: Add argument type ids to this, to ensure uniqueness
+ -- TODO: Special handling for tuples?
+ let ty_id = mkVHDLExtId $ nameToString (TyCon.tyConName tycon)
+ let ty_def = AST.TDR $ AST.RecordTypeDef elems
+ return $ Just (ty_id, ty_def)
+ dcs -> error $ "Only single constructor datatypes supported: " ++ (showSDoc $ ppr tycon)
+ where
+ -- Create a subst that instantiates all types passed to the tycon
+ -- TODO: I'm not 100% sure that this is the right way to do this. It seems
+ -- to work so far, though..
+ tyvars = TyCon.tyConTyVars tycon
+ subst = CoreSubst.extendTvSubstList CoreSubst.emptySubst (zip tyvars args)
+