--
-- Simplified attribute grammar representation
--

DATA Sag
  | Ag
      datas  : Datas
      itfs   : Itfs
      blocks : Blocks


--
-- Data declarations
--

TYPE Datas = [Data]

DATA Data
  | Data
      name : Ident
      vars : Idents
      cons : Cons

TYPE Cons = [Con]

DATA Con
  | Con
      name : Ident
      sigs : Sigs

TYPE Sigs = [Sig]

DATA Sig
  | Sig
      name : Ident
      tp   : Type


--
-- Interface declarations
--

TYPE Itfs = [Itf]

DATA Itf
  | Itf
      name : Ident
      vars : Idents
      inhs : Sigs
      ctxs : Ctxs

TYPE Ctxs = [Ctx]

DATA Ctx
  | Ctx
      name   : Ident
      syns   : Sigs
      mbTail : MaybeTail

TYPE MaybeTail = MAYBE Tail

DATA Tail
  | Tail
      mbNm : {Maybe Ident}
      tp   : Internal

--
-- Blocks
--

TYPE Blocks = [Block]

DATA Block
  | Code
      kind  : BlockKind
      items : Codes

TYPE Codes = [Code]

DATA Code
  | Plain
      pos   : Pos
      txt   : String
  | Attr
      pos   : Pos
      name  : Ident
      field : Ident
  | Sem
      pos     : Pos
      tp      : Scheme
      clauses : Clauses

TYPE Clauses = [Clause]

DATA Clause
  | Clause
      name : Ident
      ctx  : Ident
      defs : Defs

TYPE Defs = [Def]

DATA Def
  | Child
      name  : Ident
      tp    : Internal
      def   : Block
  | Visit
      child  : Ident
      mbTail : {Maybe Ident}
      ctx    : Ident
      def    : Block
  | Bind
      kind : BindKind
      pat  : Pat
      def  : Block
  | Tail
      def : Block

TYPE Pats = [Pat]

DATA Pat
  | Attr
      child : Ident
      field : Ident
  | Con
      name  : Ident
      pats  : Pats
  | Tup
      pats  : Pats
  | Underscore