INTERFACE M3AST_LX;

(***************************************************************************)
(*                      Copyright (C) Olivetti 1989                        *)
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(***************************************************************************)

(* This interface defines the types of the lexical entities in the Modula-3
   AST. At this level of the specification, most of the entities are
   declared as opaque types, to be given a definition by a particular
   implementation of the AST. The exception is source position information
   which is defined as an INTEGER, although the encoding of the bits
   is not specified here. The notions of a "comment store" and a
   "pragma store" are likely to change in a future version, in favour
   of more precise association of comments, pragmas and whitespace
   with the AST.
*)

TYPE 
  Symbol_rep <: REFANY;       (* identifiers *)
  Literal_rep <: REFANY;      (* all literals *)
  Number_rep <: Literal_rep;  (* numeric literals *)
  Text_rep <: Literal_rep;    (* text and character literals *)
  SrcPos = INTEGER;           (* source positions *)
  CommentStore <: REFANY;     (* all the comments *)
  PragmaStore <: REFANY;      (* all the pragmas *)

END M3AST_LX.