gcc/m2/mc/mcStack.def

   1 (* mcStack.def provides a stack data type and associated procedures.
   2
   3 Copyright (C) 2015-2024 Free Software Foundation, Inc.
   4 Contributed by Gaius Mulley <gaius.mulley@southwales.ac.uk>.
   5
   6 This file is part of GNU Modula-2.
   7
   8 GNU Modula-2 is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 3, or (at your option)
  11 any later version.
  12
  13 GNU Modula-2 is distributed in the hope that it will be useful, but
  14 WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16 General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with GNU Modula-2; see the file COPYING3.  If not see
  20 <http://www.gnu.org/licenses/>.  *)
  21
  22 DEFINITION MODULE mcStack ;
  23
  24
  25 FROM SYSTEM IMPORT ADDRESS ;
  26
  27 TYPE
  28    stack ;
  29
  30
  31 (*
  32    init - create and return a stack.
  33 *)
  34
  35 PROCEDURE init () : stack ;
  36
  37
  38 (*
  39    kill - deletes stack, s.
  40 *)
  41
  42 PROCEDURE kill (VAR s: stack) ;
  43
  44
  45 (*
  46    push - an address, a, onto the stack, s.
  47           It returns, a.
  48 *)
  49
  50 PROCEDURE push (s: stack; a: ADDRESS) : ADDRESS ;
  51
  52
  53 (*
  54    pop - and return the top element from stack, s.
  55 *)
  56
  57 PROCEDURE pop (s: stack) : ADDRESS ;
  58
  59
  60 (*
  61    replace - performs a pop; push (a); return a.
  62 *)
  63
  64 PROCEDURE replace (s: stack; a: ADDRESS) : ADDRESS ;
  65
  66
  67 (*
  68    depth - returns the depth of the stack.
  69 *)
  70
  71 PROCEDURE depth (s: stack) : CARDINAL ;
  72
  73
  74 (*
  75    access - returns the, i, th stack element.
  76             The top of stack is defined by:
  77
  78             access (s, depth (s)).
  79 *)
  80
  81 PROCEDURE access (s: stack; i: CARDINAL) : ADDRESS ;
  82
  83
  84 END mcStack.