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(* mcStack.def provides a stack data type and associated procedures.
Copyright (C) 2015-2023 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 mcStack ;
FROM SYSTEM IMPORT ADDRESS ;
TYPE
stack ;
(*
init - create and return a stack.
*)
PROCEDURE init () : stack ;
(*
kill - deletes stack, s.
*)
PROCEDURE kill (VAR s: stack) ;
(*
push - an address, a, onto the stack, s.
It returns, a.
*)
PROCEDURE push (s: stack; a: ADDRESS) : ADDRESS ;
(*
pop - and return the top element from stack, s.
*)
PROCEDURE pop (s: stack) : ADDRESS ;
(*
replace - performs a pop; push (a); return a.
*)
PROCEDURE replace (s: stack; a: ADDRESS) : ADDRESS ;
(*
depth - returns the depth of the stack.
*)
PROCEDURE depth (s: stack) : CARDINAL ;
(*
access - returns the, i, th stack element.
The top of stack is defined by:
access (s, depth (s)).
*)
PROCEDURE access (s: stack; i: CARDINAL) : ADDRESS ;
END mcStack.