--
-- AST for grammars with priorities
--

DATA NtIdent
  | Ident
      nm       : {Identifier}
      level    : {Int}
      suffixes : {[Symbol]}

DERIVING NtIdent : Eq, Ord


DATA GrammarRoot
  | Root
      gram : Grammar

TYPE Grammar = MAP {NtIdent} Productions

TYPE Productions = [Production]

DATA Production
  | Prod
      sem     : {ProdSem}
      symbols : Symbols

TYPE ProdName = MAYBE {Identifier}

TYPE Symbols = [Symbol]

DATA Symbol
  | Term
      token : {String}
  | Nonterm
      ref   : {NtIdent}
  | PrimString
  | PrimInt
  | PrimIdent
  | Root

DERIVING Symbol : Eq, Ord

DATA ProdSem
  | Identity
  | Parentheses
  | Name
      nm     : {Identifier}
      fields : {[Maybe Identifier]}
  | Lam
      sem : ProdSem
  | App
      sem : ProdSem


DATA ParseResult
  | Tree
      tree : {ParseTree}
  | Function
      fun  : {[ParseResult] -> ParseResult}

DATA ParseTree
  | Alternative
      pos      : {Pos}
      alt      : {Identifier}
      children : ParseForest
  | Terminal
      nm       : {Identifier}
  | PrimString
      pos      : {Pos}
      str      : {String}
  | PrimInt
      pos      : {Pos}
      int      : {Int}
  | PrimIdent
      nm       : {Identifier}
  | Amb
      children : ParseTrees
  | Parentheses
      tree     : ParseTree

TYPE ParseForest = MAP {Identifier} ParseTree
TYPE ParseTrees = [ParseTree]