(* M2StackAddress.def provides a generic stack for ADDRESS sized objects.

Copyright (C) 2001-2025 Free Software Foundation, Inc.
Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.

This file is part of GNU Modula-2.

GNU Modula-2 is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3, or (at your option)
any later version.

GNU Modula-2 is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Modula-2; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  *)

DEFINITION MODULE M2StackAddress ;

(*
    Title      : M2StackAddress
    Author     : Gaius Mulley
    System     : UNIX (GNU Modula-2)
    Date       : Fri Oct 12 17:26:50 2001
    Revision   : $Version$
    Description: provides a generic stack for ADDRESS sized objects.
*)

FROM SYSTEM IMPORT ADDRESS ;
EXPORT QUALIFIED StackOfAddress, InitStackAddress, KillStackAddress,
                 PushAddress, PopAddress, PeepAddress,
                 IsEmptyAddress, NoOfItemsInStackAddress ;

TYPE
   StackOfAddress ;


(*
   InitStackAddress - creates and returns a new stack.
*)

PROCEDURE InitStackAddress () : StackOfAddress ;


(*
   KillStackAddress - destroys a stack, returning NIL.
*)

PROCEDURE KillStackAddress (s: StackOfAddress) : StackOfAddress ;


(*
   PushAddress - pushes a word, w, onto, s.
*)

PROCEDURE PushAddress (s: StackOfAddress; w: ADDRESS) ;


(*
   PopAddress - pops an element from stack, s.
*)

PROCEDURE PopAddress (s: StackOfAddress) : ADDRESS ;


(*
   IsEmptyAddress - returns TRUE if stack, s, is empty.
*)

PROCEDURE IsEmptyAddress (s: StackOfAddress) : BOOLEAN ;


(*
   PeepAddress - returns the element at, n, items below in the stack.
                 Top of stack can be seen via Peep(s, 1)
*)

PROCEDURE PeepAddress (s: StackOfAddress; n: CARDINAL) : ADDRESS ;


(*
   ReduceAddress - reduce the stack by n elements.
*)

PROCEDURE ReduceAddress (s: StackOfAddress; n: CARDINAL) ;


(*
   NoOfItemsInStack - returns the number of items held in the stack, s.
*)

PROCEDURE NoOfItemsInStackAddress (s: StackOfAddress) : CARDINAL ;


END M2StackAddress.