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-------------------------------------------------------------------------------
-- (C) Altran Praxis Limited
-------------------------------------------------------------------------------
--
-- The SPARK toolset is free software; you can redistribute it and/or modify it
-- under terms of the GNU General Public License as published by the Free
-- Software Foundation; either version 3, or (at your option) any later
-- version. The SPARK toolset 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 distributed with the SPARK toolset; see file
-- COPYING3. If not, go to http://www.gnu.org/licenses for a complete copy of
-- the license.
--
--=============================================================================
with Unit;
--# inherit Unit;
package Units is
type Stack is private;
NullStack : constant Stack;
type Iterator is private;
----------------------------------------------------------
-- Id Stack
----------------------------------------------------------
function InStack (TheUnit : in Unit.Id;
TheStack : in Stack) return Boolean;
procedure Push (TheStack : in out Stack;
TheUnit : in Unit.Id);
--# derives TheStack from *,
--# TheUnit;
procedure Pop (TheStack : in out Stack;
TheUnit : out Unit.Id);
--# derives TheStack,
--# TheUnit from TheStack;
function IsEmpty (TheStack : Stack) return Boolean;
procedure Sort (TheUnits : in out Stack);
--# derives TheUnits from *;
procedure Init_Iterator (TheStack : in Stack;
TheIterator : out Iterator);
--# derives TheIterator from TheStack;
function Iterated (TheIterator : in Iterator) return Boolean;
procedure Iterate (TheIterator : in out Iterator;
TheUnit : out Unit.Id);
--# derives TheIterator,
--# TheUnit from TheIterator;
private
--# hide Units;
type Node;
type Stack is access Node;
NullStack : constant Stack := null;
type Node is record
TheItem : Unit.Id;
Next : Stack;
end record;
type Iterator is new Stack;
end Units;
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