(* Copyright (C) 1990, Digital Equipment Corporation.         *)
(* All rights reserved.                                       *)
(* See the file COPYRIGHT for a full description.             *)

(* Last modified on Wed Mar 21 21:55:04 1990 by muller        *)


INTERFACE M3Entity;

(* An Entity.T is a thing that can be denoted by a name in a Modula-3 
   program. *)

IMPORT M3Type, M3Value;

TYPE
  T <: ROOT;
  (* Constant | Type | Variable | Exception | Interface | Module 
   | Procedure | Operator *)

  Constant = T OBJECT
    type: M3Type.T;
    value: M3Value.T;
  END;
  (* A constant entity e represents the Modula-3 value with type 
  e.type and value e.value. *)

  Type = T OBJECT
    type: M3Type.T
  END;
  (* A Type entity e represents the type e.type *)

  Variable = T OBJECT
    type: M3Type.T;
  END;
  (* Parameter | Local | Global *)
  
  Parameter <: Variable;
  (* A procedure parameter *)

  Local <: Variable;
  (* A procedure local *)

  Global <: Variable;
  (* A variable declared in an interface or module. *)
  
  Exception = T OBJECT
    exception: M3Value.Exception;
    argType: M3Type.T (* NIL if there is no argument *)
  END;

  Procedure = T OBJECT
    proc: M3Value.Procedure;
    signature: M3Type.Signature
  END;

  Interface <: T;

  Module <: T;
    
  Operator = T OBJECT
    ops: REF ARRAY OF Operation
  END;
  (* One operation for each overloading of the operator. *)

  Operation = {
   Hat, (* r^ *)
   Sub, (* array[ ] *)
   HatSub, (* refArray[ ] *)
   RecordDot, (* record.field *)
   RecordHatDot, (* refRecord.field *)
   ObjectDot, (* object.field *)
   InterfaceDot, (* Interface.entity *)
   ObjTypeDot, (* ObjectType.methodname *)
   EnumDot, (* Enumeration.element *)
   Subarray, (* The SUBARRAY operation *)
   NewObject, (* The NEW operation on objects *)
   NewOpenArray, (* The NEW operation on open arrays *)
   New, (* Other NEW operations *)
   PlusInt, (* int + int *)
   PlusReal (* real + real *)

   (* ... only 77 more lines to go... *) };
   
END M3Entity.