2395 lines
68 KiB
Ada
2395 lines
68 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT LIBRARY COMPONENTS --
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-- --
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-- ADA.CONTAINERS.BOUNDED_DOUBLY_LINKED_LISTS --
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-- --
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-- B o d y --
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-- --
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-- Copyright (C) 2004-2015, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- This unit was originally developed by Matthew J Heaney. --
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------------------------------------------------------------------------------
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with System; use type System.Address;
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package body Ada.Containers.Bounded_Doubly_Linked_Lists is
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pragma Warnings (Off, "variable ""Busy*"" is not referenced");
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pragma Warnings (Off, "variable ""Lock*"" is not referenced");
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-- See comment in Ada.Containers.Helpers
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-----------------------
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-- Local Subprograms --
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-----------------------
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procedure Allocate
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(Container : in out List;
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New_Item : Element_Type;
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New_Node : out Count_Type);
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procedure Allocate
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(Container : in out List;
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Stream : not null access Root_Stream_Type'Class;
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New_Node : out Count_Type);
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procedure Free
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(Container : in out List;
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X : Count_Type);
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procedure Insert_Internal
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(Container : in out List;
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Before : Count_Type;
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New_Node : Count_Type);
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procedure Splice_Internal
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(Target : in out List;
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Before : Count_Type;
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Source : in out List);
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procedure Splice_Internal
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(Target : in out List;
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Before : Count_Type;
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Source : in out List;
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Src_Pos : Count_Type;
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Tgt_Pos : out Count_Type);
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function Vet (Position : Cursor) return Boolean;
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-- Checks invariants of the cursor and its designated container, as a
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-- simple way of detecting dangling references (see operation Free for a
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-- description of the detection mechanism), returning True if all checks
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-- pass. Invocations of Vet are used here as the argument of pragma Assert,
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-- so the checks are performed only when assertions are enabled.
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---------
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-- "=" --
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---------
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function "=" (Left, Right : List) return Boolean is
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begin
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if Left.Length /= Right.Length then
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return False;
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end if;
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if Left.Length = 0 then
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return True;
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end if;
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declare
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-- Per AI05-0022, the container implementation is required to detect
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-- element tampering by a generic actual subprogram.
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Lock_Left : With_Lock (Left.TC'Unrestricted_Access);
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Lock_Right : With_Lock (Right.TC'Unrestricted_Access);
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LN : Node_Array renames Left.Nodes;
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RN : Node_Array renames Right.Nodes;
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LI : Count_Type := Left.First;
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RI : Count_Type := Right.First;
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begin
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for J in 1 .. Left.Length loop
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if LN (LI).Element /= RN (RI).Element then
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return False;
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end if;
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LI := LN (LI).Next;
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RI := RN (RI).Next;
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end loop;
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end;
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return True;
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end "=";
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--------------
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-- Allocate --
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--------------
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procedure Allocate
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(Container : in out List;
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New_Item : Element_Type;
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New_Node : out Count_Type)
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is
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N : Node_Array renames Container.Nodes;
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begin
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if Container.Free >= 0 then
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New_Node := Container.Free;
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-- We always perform the assignment first, before we change container
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-- state, in order to defend against exceptions duration assignment.
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N (New_Node).Element := New_Item;
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Container.Free := N (New_Node).Next;
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else
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-- A negative free store value means that the links of the nodes in
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-- the free store have not been initialized. In this case, the nodes
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-- are physically contiguous in the array, starting at the index that
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-- is the absolute value of the Container.Free, and continuing until
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-- the end of the array (Nodes'Last).
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New_Node := abs Container.Free;
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-- As above, we perform this assignment first, before modifying any
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-- container state.
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N (New_Node).Element := New_Item;
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Container.Free := Container.Free - 1;
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end if;
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end Allocate;
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procedure Allocate
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(Container : in out List;
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Stream : not null access Root_Stream_Type'Class;
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New_Node : out Count_Type)
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is
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N : Node_Array renames Container.Nodes;
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begin
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if Container.Free >= 0 then
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New_Node := Container.Free;
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-- We always perform the assignment first, before we change container
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-- state, in order to defend against exceptions duration assignment.
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Element_Type'Read (Stream, N (New_Node).Element);
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Container.Free := N (New_Node).Next;
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else
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-- A negative free store value means that the links of the nodes in
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-- the free store have not been initialized. In this case, the nodes
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-- are physically contiguous in the array, starting at the index that
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-- is the absolute value of the Container.Free, and continuing until
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-- the end of the array (Nodes'Last).
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New_Node := abs Container.Free;
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-- As above, we perform this assignment first, before modifying any
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-- container state.
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Element_Type'Read (Stream, N (New_Node).Element);
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Container.Free := Container.Free - 1;
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end if;
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end Allocate;
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------------
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-- Append --
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------------
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procedure Append
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(Container : in out List;
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New_Item : Element_Type;
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Count : Count_Type := 1)
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is
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begin
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Insert (Container, No_Element, New_Item, Count);
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end Append;
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------------
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-- Assign --
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------------
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procedure Assign (Target : in out List; Source : List) is
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SN : Node_Array renames Source.Nodes;
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J : Count_Type;
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begin
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if Target'Address = Source'Address then
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return;
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end if;
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if Checks and then Target.Capacity < Source.Length then
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raise Capacity_Error -- ???
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with "Target capacity is less than Source length";
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end if;
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Target.Clear;
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J := Source.First;
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while J /= 0 loop
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Target.Append (SN (J).Element);
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J := SN (J).Next;
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end loop;
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end Assign;
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-----------
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-- Clear --
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-----------
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procedure Clear (Container : in out List) is
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N : Node_Array renames Container.Nodes;
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X : Count_Type;
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begin
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if Container.Length = 0 then
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pragma Assert (Container.First = 0);
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pragma Assert (Container.Last = 0);
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pragma Assert (Container.TC = (Busy => 0, Lock => 0));
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return;
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end if;
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pragma Assert (Container.First >= 1);
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pragma Assert (Container.Last >= 1);
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pragma Assert (N (Container.First).Prev = 0);
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pragma Assert (N (Container.Last).Next = 0);
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TC_Check (Container.TC);
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while Container.Length > 1 loop
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X := Container.First;
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pragma Assert (N (N (X).Next).Prev = Container.First);
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Container.First := N (X).Next;
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N (Container.First).Prev := 0;
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Container.Length := Container.Length - 1;
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Free (Container, X);
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end loop;
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X := Container.First;
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pragma Assert (X = Container.Last);
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Container.First := 0;
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Container.Last := 0;
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Container.Length := 0;
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Free (Container, X);
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end Clear;
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------------------------
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-- Constant_Reference --
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------------------------
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function Constant_Reference
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(Container : aliased List;
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Position : Cursor) return Constant_Reference_Type
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is
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begin
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if Checks and then Position.Container = null then
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raise Constraint_Error with "Position cursor has no element";
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end if;
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if Checks and then Position.Container /= Container'Unrestricted_Access
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then
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raise Program_Error with
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"Position cursor designates wrong container";
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end if;
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pragma Assert (Vet (Position), "bad cursor in Constant_Reference");
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declare
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N : Node_Type renames Container.Nodes (Position.Node);
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TC : constant Tamper_Counts_Access :=
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Container.TC'Unrestricted_Access;
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begin
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return R : constant Constant_Reference_Type :=
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(Element => N.Element'Access,
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Control => (Controlled with TC))
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do
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Lock (TC.all);
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end return;
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end;
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end Constant_Reference;
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--------------
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-- Contains --
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--------------
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function Contains
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(Container : List;
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Item : Element_Type) return Boolean
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is
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begin
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return Find (Container, Item) /= No_Element;
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end Contains;
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----------
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-- Copy --
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----------
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function Copy (Source : List; Capacity : Count_Type := 0) return List is
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C : Count_Type;
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begin
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if Capacity = 0 then
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C := Source.Length;
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elsif Capacity >= Source.Length then
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C := Capacity;
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elsif Checks then
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raise Capacity_Error with "Capacity value too small";
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end if;
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return Target : List (Capacity => C) do
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Assign (Target => Target, Source => Source);
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end return;
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end Copy;
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------------
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-- Delete --
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------------
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procedure Delete
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(Container : in out List;
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Position : in out Cursor;
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Count : Count_Type := 1)
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is
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N : Node_Array renames Container.Nodes;
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X : Count_Type;
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begin
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if Checks and then Position.Node = 0 then
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raise Constraint_Error with
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"Position cursor has no element";
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end if;
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if Checks and then Position.Container /= Container'Unrestricted_Access
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then
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raise Program_Error with
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"Position cursor designates wrong container";
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end if;
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pragma Assert (Vet (Position), "bad cursor in Delete");
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pragma Assert (Container.First >= 1);
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pragma Assert (Container.Last >= 1);
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pragma Assert (N (Container.First).Prev = 0);
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pragma Assert (N (Container.Last).Next = 0);
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if Position.Node = Container.First then
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Delete_First (Container, Count);
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Position := No_Element;
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return;
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end if;
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if Count = 0 then
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Position := No_Element;
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return;
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end if;
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TC_Check (Container.TC);
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for Index in 1 .. Count loop
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pragma Assert (Container.Length >= 2);
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X := Position.Node;
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Container.Length := Container.Length - 1;
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if X = Container.Last then
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Position := No_Element;
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Container.Last := N (X).Prev;
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N (Container.Last).Next := 0;
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Free (Container, X);
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return;
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end if;
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Position.Node := N (X).Next;
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N (N (X).Next).Prev := N (X).Prev;
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N (N (X).Prev).Next := N (X).Next;
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Free (Container, X);
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end loop;
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Position := No_Element;
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end Delete;
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------------------
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-- Delete_First --
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------------------
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procedure Delete_First
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(Container : in out List;
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Count : Count_Type := 1)
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is
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N : Node_Array renames Container.Nodes;
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X : Count_Type;
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begin
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if Count >= Container.Length then
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Clear (Container);
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return;
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end if;
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if Count = 0 then
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return;
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end if;
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TC_Check (Container.TC);
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for J in 1 .. Count loop
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X := Container.First;
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pragma Assert (N (N (X).Next).Prev = Container.First);
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Container.First := N (X).Next;
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N (Container.First).Prev := 0;
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Container.Length := Container.Length - 1;
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Free (Container, X);
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end loop;
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end Delete_First;
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-----------------
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-- Delete_Last --
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-----------------
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procedure Delete_Last
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(Container : in out List;
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Count : Count_Type := 1)
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is
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N : Node_Array renames Container.Nodes;
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X : Count_Type;
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begin
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if Count >= Container.Length then
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Clear (Container);
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return;
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end if;
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if Count = 0 then
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return;
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end if;
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TC_Check (Container.TC);
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for J in 1 .. Count loop
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X := Container.Last;
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pragma Assert (N (N (X).Prev).Next = Container.Last);
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Container.Last := N (X).Prev;
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N (Container.Last).Next := 0;
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Container.Length := Container.Length - 1;
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Free (Container, X);
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end loop;
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end Delete_Last;
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-------------
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-- Element --
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-------------
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function Element (Position : Cursor) return Element_Type is
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begin
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if Checks and then Position.Node = 0 then
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raise Constraint_Error with
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"Position cursor has no element";
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end if;
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pragma Assert (Vet (Position), "bad cursor in Element");
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return Position.Container.Nodes (Position.Node).Element;
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end Element;
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--------------
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-- Finalize --
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--------------
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procedure Finalize (Object : in out Iterator) is
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begin
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if Object.Container /= null then
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Unbusy (Object.Container.TC);
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end if;
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end Finalize;
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----------
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-- Find --
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----------
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function Find
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(Container : List;
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Item : Element_Type;
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Position : Cursor := No_Element) return Cursor
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is
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Nodes : Node_Array renames Container.Nodes;
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Node : Count_Type := Position.Node;
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begin
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if Node = 0 then
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Node := Container.First;
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else
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if Checks and then Position.Container /= Container'Unrestricted_Access
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then
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raise Program_Error with
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"Position cursor designates wrong container";
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end if;
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pragma Assert (Vet (Position), "bad cursor in Find");
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end if;
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|
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-- Per AI05-0022, the container implementation is required to detect
|
|
-- element tampering by a generic actual subprogram.
|
|
|
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declare
|
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Lock : With_Lock (Container.TC'Unrestricted_Access);
|
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begin
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while Node /= 0 loop
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if Nodes (Node).Element = Item then
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return Cursor'(Container'Unrestricted_Access, Node);
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end if;
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Node := Nodes (Node).Next;
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end loop;
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return No_Element;
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end;
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end Find;
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|
|
-----------
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-- First --
|
|
-----------
|
|
|
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function First (Container : List) return Cursor is
|
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begin
|
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if Container.First = 0 then
|
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return No_Element;
|
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else
|
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return Cursor'(Container'Unrestricted_Access, Container.First);
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end if;
|
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end First;
|
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|
|
function First (Object : Iterator) return Cursor is
|
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begin
|
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-- The value of the iterator object's Node component influences the
|
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-- behavior of the First (and Last) selector function.
|
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|
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-- When the Node component is 0, this means the iterator object was
|
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-- constructed without a start expression, in which case the (forward)
|
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-- iteration starts from the (logical) beginning of the entire sequence
|
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-- of items (corresponding to Container.First, for a forward iterator).
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-- Otherwise, this is iteration over a partial sequence of items. When
|
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-- the Node component is positive, the iterator object was constructed
|
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-- with a start expression, that specifies the position from which the
|
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-- (forward) partial iteration begins.
|
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|
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if Object.Node = 0 then
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return Bounded_Doubly_Linked_Lists.First (Object.Container.all);
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else
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return Cursor'(Object.Container, Object.Node);
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end if;
|
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end First;
|
|
|
|
-------------------
|
|
-- First_Element --
|
|
-------------------
|
|
|
|
function First_Element (Container : List) return Element_Type is
|
|
begin
|
|
if Checks and then Container.First = 0 then
|
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raise Constraint_Error with "list is empty";
|
|
end if;
|
|
|
|
return Container.Nodes (Container.First).Element;
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|
end First_Element;
|
|
|
|
----------
|
|
-- Free --
|
|
----------
|
|
|
|
procedure Free
|
|
(Container : in out List;
|
|
X : Count_Type)
|
|
is
|
|
pragma Assert (X > 0);
|
|
pragma Assert (X <= Container.Capacity);
|
|
|
|
N : Node_Array renames Container.Nodes;
|
|
pragma Assert (N (X).Prev >= 0); -- node is active
|
|
|
|
begin
|
|
-- The list container actually contains two lists: one for the "active"
|
|
-- nodes that contain elements that have been inserted onto the list,
|
|
-- and another for the "inactive" nodes for the free store.
|
|
|
|
-- We desire that merely declaring an object should have only minimal
|
|
-- cost; specially, we want to avoid having to initialize the free
|
|
-- store (to fill in the links), especially if the capacity is large.
|
|
|
|
-- The head of the free list is indicated by Container.Free. If its
|
|
-- value is non-negative, then the free store has been initialized in
|
|
-- the "normal" way: Container.Free points to the head of the list of
|
|
-- free (inactive) nodes, and the value 0 means the free list is empty.
|
|
-- Each node on the free list has been initialized to point to the next
|
|
-- free node (via its Next component), and the value 0 means that this
|
|
-- is the last free node.
|
|
|
|
-- If Container.Free is negative, then the links on the free store have
|
|
-- not been initialized. In this case the link values are implied: the
|
|
-- free store comprises the components of the node array started with
|
|
-- the absolute value of Container.Free, and continuing until the end of
|
|
-- the array (Nodes'Last).
|
|
|
|
-- If the list container is manipulated on one end only (for example if
|
|
-- the container were being used as a stack), then there is no need to
|
|
-- initialize the free store, since the inactive nodes are physically
|
|
-- contiguous (in fact, they lie immediately beyond the logical end
|
|
-- being manipulated). The only time we need to actually initialize the
|
|
-- nodes in the free store is if the node that becomes inactive is not
|
|
-- at the end of the list. The free store would then be discontiguous
|
|
-- and so its nodes would need to be linked in the traditional way.
|
|
|
|
-- ???
|
|
-- It might be possible to perform an optimization here. Suppose that
|
|
-- the free store can be represented as having two parts: one comprising
|
|
-- the non-contiguous inactive nodes linked together in the normal way,
|
|
-- and the other comprising the contiguous inactive nodes (that are not
|
|
-- linked together, at the end of the nodes array). This would allow us
|
|
-- to never have to initialize the free store, except in a lazy way as
|
|
-- nodes become inactive.
|
|
|
|
-- When an element is deleted from the list container, its node becomes
|
|
-- inactive, and so we set its Prev component to a negative value, to
|
|
-- indicate that it is now inactive. This provides a useful way to
|
|
-- detect a dangling cursor reference (and which is used in Vet).
|
|
|
|
N (X).Prev := -1; -- Node is deallocated (not on active list)
|
|
|
|
if Container.Free >= 0 then
|
|
|
|
-- The free store has previously been initialized. All we need to
|
|
-- do here is link the newly-free'd node onto the free list.
|
|
|
|
N (X).Next := Container.Free;
|
|
Container.Free := X;
|
|
|
|
elsif X + 1 = abs Container.Free then
|
|
|
|
-- The free store has not been initialized, and the node becoming
|
|
-- inactive immediately precedes the start of the free store. All
|
|
-- we need to do is move the start of the free store back by one.
|
|
|
|
-- Note: initializing Next to zero is not strictly necessary but
|
|
-- seems cleaner and marginally safer.
|
|
|
|
N (X).Next := 0;
|
|
Container.Free := Container.Free + 1;
|
|
|
|
else
|
|
-- The free store has not been initialized, and the node becoming
|
|
-- inactive does not immediately precede the free store. Here we
|
|
-- first initialize the free store (meaning the links are given
|
|
-- values in the traditional way), and then link the newly-free'd
|
|
-- node onto the head of the free store.
|
|
|
|
-- ???
|
|
-- See the comments above for an optimization opportunity. If the
|
|
-- next link for a node on the free store is negative, then this
|
|
-- means the remaining nodes on the free store are physically
|
|
-- contiguous, starting as the absolute value of that index value.
|
|
|
|
Container.Free := abs Container.Free;
|
|
|
|
if Container.Free > Container.Capacity then
|
|
Container.Free := 0;
|
|
|
|
else
|
|
for I in Container.Free .. Container.Capacity - 1 loop
|
|
N (I).Next := I + 1;
|
|
end loop;
|
|
|
|
N (Container.Capacity).Next := 0;
|
|
end if;
|
|
|
|
N (X).Next := Container.Free;
|
|
Container.Free := X;
|
|
end if;
|
|
end Free;
|
|
|
|
---------------------
|
|
-- Generic_Sorting --
|
|
---------------------
|
|
|
|
package body Generic_Sorting is
|
|
|
|
---------------
|
|
-- Is_Sorted --
|
|
---------------
|
|
|
|
function Is_Sorted (Container : List) return Boolean is
|
|
-- Per AI05-0022, the container implementation is required to detect
|
|
-- element tampering by a generic actual subprogram.
|
|
|
|
Lock : With_Lock (Container.TC'Unrestricted_Access);
|
|
|
|
Nodes : Node_Array renames Container.Nodes;
|
|
Node : Count_Type;
|
|
begin
|
|
Node := Container.First;
|
|
for J in 2 .. Container.Length loop
|
|
if Nodes (Nodes (Node).Next).Element < Nodes (Node).Element then
|
|
return False;
|
|
end if;
|
|
|
|
Node := Nodes (Node).Next;
|
|
end loop;
|
|
|
|
return True;
|
|
end Is_Sorted;
|
|
|
|
-----------
|
|
-- Merge --
|
|
-----------
|
|
|
|
procedure Merge
|
|
(Target : in out List;
|
|
Source : in out List)
|
|
is
|
|
begin
|
|
-- The semantics of Merge changed slightly per AI05-0021. It was
|
|
-- originally the case that if Target and Source denoted the same
|
|
-- container object, then the GNAT implementation of Merge did
|
|
-- nothing. However, it was argued that RM05 did not precisely
|
|
-- specify the semantics for this corner case. The decision of the
|
|
-- ARG was that if Target and Source denote the same non-empty
|
|
-- container object, then Program_Error is raised.
|
|
|
|
if Source.Is_Empty then
|
|
return;
|
|
end if;
|
|
|
|
if Checks and then Target'Address = Source'Address then
|
|
raise Program_Error with
|
|
"Target and Source denote same non-empty container";
|
|
end if;
|
|
|
|
if Checks and then Target.Length > Count_Type'Last - Source.Length
|
|
then
|
|
raise Constraint_Error with "new length exceeds maximum";
|
|
end if;
|
|
|
|
if Checks and then Target.Length + Source.Length > Target.Capacity
|
|
then
|
|
raise Capacity_Error with "new length exceeds target capacity";
|
|
end if;
|
|
|
|
TC_Check (Target.TC);
|
|
TC_Check (Source.TC);
|
|
|
|
-- Per AI05-0022, the container implementation is required to detect
|
|
-- element tampering by a generic actual subprogram.
|
|
|
|
declare
|
|
Lock_Target : With_Lock (Target.TC'Unchecked_Access);
|
|
Lock_Source : With_Lock (Source.TC'Unchecked_Access);
|
|
|
|
LN : Node_Array renames Target.Nodes;
|
|
RN : Node_Array renames Source.Nodes;
|
|
|
|
LI, LJ, RI, RJ : Count_Type;
|
|
|
|
begin
|
|
LI := Target.First;
|
|
RI := Source.First;
|
|
while RI /= 0 loop
|
|
pragma Assert (RN (RI).Next = 0
|
|
or else not (RN (RN (RI).Next).Element <
|
|
RN (RI).Element));
|
|
|
|
if LI = 0 then
|
|
Splice_Internal (Target, 0, Source);
|
|
exit;
|
|
end if;
|
|
|
|
pragma Assert (LN (LI).Next = 0
|
|
or else not (LN (LN (LI).Next).Element <
|
|
LN (LI).Element));
|
|
|
|
if RN (RI).Element < LN (LI).Element then
|
|
RJ := RI;
|
|
RI := RN (RI).Next;
|
|
Splice_Internal (Target, LI, Source, RJ, LJ);
|
|
|
|
else
|
|
LI := LN (LI).Next;
|
|
end if;
|
|
end loop;
|
|
end;
|
|
end Merge;
|
|
|
|
----------
|
|
-- Sort --
|
|
----------
|
|
|
|
procedure Sort (Container : in out List) is
|
|
N : Node_Array renames Container.Nodes;
|
|
|
|
procedure Partition (Pivot, Back : Count_Type);
|
|
-- What does this do ???
|
|
|
|
procedure Sort (Front, Back : Count_Type);
|
|
-- Internal procedure, what does it do??? rename it???
|
|
|
|
---------------
|
|
-- Partition --
|
|
---------------
|
|
|
|
procedure Partition (Pivot, Back : Count_Type) is
|
|
Node : Count_Type;
|
|
|
|
begin
|
|
Node := N (Pivot).Next;
|
|
while Node /= Back loop
|
|
if N (Node).Element < N (Pivot).Element then
|
|
declare
|
|
Prev : constant Count_Type := N (Node).Prev;
|
|
Next : constant Count_Type := N (Node).Next;
|
|
|
|
begin
|
|
N (Prev).Next := Next;
|
|
|
|
if Next = 0 then
|
|
Container.Last := Prev;
|
|
else
|
|
N (Next).Prev := Prev;
|
|
end if;
|
|
|
|
N (Node).Next := Pivot;
|
|
N (Node).Prev := N (Pivot).Prev;
|
|
|
|
N (Pivot).Prev := Node;
|
|
|
|
if N (Node).Prev = 0 then
|
|
Container.First := Node;
|
|
else
|
|
N (N (Node).Prev).Next := Node;
|
|
end if;
|
|
|
|
Node := Next;
|
|
end;
|
|
|
|
else
|
|
Node := N (Node).Next;
|
|
end if;
|
|
end loop;
|
|
end Partition;
|
|
|
|
----------
|
|
-- Sort --
|
|
----------
|
|
|
|
procedure Sort (Front, Back : Count_Type) is
|
|
Pivot : constant Count_Type :=
|
|
(if Front = 0 then Container.First else N (Front).Next);
|
|
begin
|
|
if Pivot /= Back then
|
|
Partition (Pivot, Back);
|
|
Sort (Front, Pivot);
|
|
Sort (Pivot, Back);
|
|
end if;
|
|
end Sort;
|
|
|
|
-- Start of processing for Sort
|
|
|
|
begin
|
|
if Container.Length <= 1 then
|
|
return;
|
|
end if;
|
|
|
|
pragma Assert (N (Container.First).Prev = 0);
|
|
pragma Assert (N (Container.Last).Next = 0);
|
|
|
|
TC_Check (Container.TC);
|
|
|
|
-- Per AI05-0022, the container implementation is required to detect
|
|
-- element tampering by a generic actual subprogram.
|
|
|
|
declare
|
|
Lock : With_Lock (Container.TC'Unchecked_Access);
|
|
begin
|
|
Sort (Front => 0, Back => 0);
|
|
end;
|
|
|
|
pragma Assert (N (Container.First).Prev = 0);
|
|
pragma Assert (N (Container.Last).Next = 0);
|
|
end Sort;
|
|
|
|
end Generic_Sorting;
|
|
|
|
------------------------
|
|
-- Get_Element_Access --
|
|
------------------------
|
|
|
|
function Get_Element_Access
|
|
(Position : Cursor) return not null Element_Access is
|
|
begin
|
|
return Position.Container.Nodes (Position.Node).Element'Access;
|
|
end Get_Element_Access;
|
|
|
|
-----------------
|
|
-- Has_Element --
|
|
-----------------
|
|
|
|
function Has_Element (Position : Cursor) return Boolean is
|
|
begin
|
|
pragma Assert (Vet (Position), "bad cursor in Has_Element");
|
|
return Position.Node /= 0;
|
|
end Has_Element;
|
|
|
|
------------
|
|
-- Insert --
|
|
------------
|
|
|
|
procedure Insert
|
|
(Container : in out List;
|
|
Before : Cursor;
|
|
New_Item : Element_Type;
|
|
Position : out Cursor;
|
|
Count : Count_Type := 1)
|
|
is
|
|
First_Node : Count_Type;
|
|
New_Node : Count_Type;
|
|
|
|
begin
|
|
if Before.Container /= null then
|
|
if Checks and then Before.Container /= Container'Unrestricted_Access
|
|
then
|
|
raise Program_Error with
|
|
"Before cursor designates wrong list";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Before), "bad cursor in Insert");
|
|
end if;
|
|
|
|
if Count = 0 then
|
|
Position := Before;
|
|
return;
|
|
end if;
|
|
|
|
if Checks and then Container.Length > Container.Capacity - Count then
|
|
raise Capacity_Error with "capacity exceeded";
|
|
end if;
|
|
|
|
TC_Check (Container.TC);
|
|
|
|
Allocate (Container, New_Item, New_Node);
|
|
First_Node := New_Node;
|
|
Insert_Internal (Container, Before.Node, New_Node);
|
|
|
|
for Index in Count_Type'(2) .. Count loop
|
|
Allocate (Container, New_Item, New_Node);
|
|
Insert_Internal (Container, Before.Node, New_Node);
|
|
end loop;
|
|
|
|
Position := Cursor'(Container'Unchecked_Access, First_Node);
|
|
end Insert;
|
|
|
|
procedure Insert
|
|
(Container : in out List;
|
|
Before : Cursor;
|
|
New_Item : Element_Type;
|
|
Count : Count_Type := 1)
|
|
is
|
|
Position : Cursor;
|
|
pragma Unreferenced (Position);
|
|
begin
|
|
Insert (Container, Before, New_Item, Position, Count);
|
|
end Insert;
|
|
|
|
procedure Insert
|
|
(Container : in out List;
|
|
Before : Cursor;
|
|
Position : out Cursor;
|
|
Count : Count_Type := 1)
|
|
is
|
|
New_Item : Element_Type;
|
|
pragma Unmodified (New_Item);
|
|
-- OK to reference, see below
|
|
|
|
begin
|
|
-- There is no explicit element provided, but in an instance the element
|
|
-- type may be a scalar with a Default_Value aspect, or a composite
|
|
-- type with such a scalar component, or components with default
|
|
-- initialization, so insert the specified number of possibly
|
|
-- initialized elements at the given position.
|
|
|
|
Insert (Container, Before, New_Item, Position, Count);
|
|
end Insert;
|
|
|
|
---------------------
|
|
-- Insert_Internal --
|
|
---------------------
|
|
|
|
procedure Insert_Internal
|
|
(Container : in out List;
|
|
Before : Count_Type;
|
|
New_Node : Count_Type)
|
|
is
|
|
N : Node_Array renames Container.Nodes;
|
|
|
|
begin
|
|
if Container.Length = 0 then
|
|
pragma Assert (Before = 0);
|
|
pragma Assert (Container.First = 0);
|
|
pragma Assert (Container.Last = 0);
|
|
|
|
Container.First := New_Node;
|
|
N (Container.First).Prev := 0;
|
|
|
|
Container.Last := New_Node;
|
|
N (Container.Last).Next := 0;
|
|
|
|
-- Before = zero means append
|
|
|
|
elsif Before = 0 then
|
|
pragma Assert (N (Container.Last).Next = 0);
|
|
|
|
N (Container.Last).Next := New_Node;
|
|
N (New_Node).Prev := Container.Last;
|
|
|
|
Container.Last := New_Node;
|
|
N (Container.Last).Next := 0;
|
|
|
|
-- Before = Container.First means prepend
|
|
|
|
elsif Before = Container.First then
|
|
pragma Assert (N (Container.First).Prev = 0);
|
|
|
|
N (Container.First).Prev := New_Node;
|
|
N (New_Node).Next := Container.First;
|
|
|
|
Container.First := New_Node;
|
|
N (Container.First).Prev := 0;
|
|
|
|
else
|
|
pragma Assert (N (Container.First).Prev = 0);
|
|
pragma Assert (N (Container.Last).Next = 0);
|
|
|
|
N (New_Node).Next := Before;
|
|
N (New_Node).Prev := N (Before).Prev;
|
|
|
|
N (N (Before).Prev).Next := New_Node;
|
|
N (Before).Prev := New_Node;
|
|
end if;
|
|
|
|
Container.Length := Container.Length + 1;
|
|
end Insert_Internal;
|
|
|
|
--------------
|
|
-- Is_Empty --
|
|
--------------
|
|
|
|
function Is_Empty (Container : List) return Boolean is
|
|
begin
|
|
return Container.Length = 0;
|
|
end Is_Empty;
|
|
|
|
-------------
|
|
-- Iterate --
|
|
-------------
|
|
|
|
procedure Iterate
|
|
(Container : List;
|
|
Process : not null access procedure (Position : Cursor))
|
|
is
|
|
Busy : With_Busy (Container.TC'Unrestricted_Access);
|
|
Node : Count_Type := Container.First;
|
|
|
|
begin
|
|
while Node /= 0 loop
|
|
Process (Cursor'(Container'Unrestricted_Access, Node));
|
|
Node := Container.Nodes (Node).Next;
|
|
end loop;
|
|
end Iterate;
|
|
|
|
function Iterate
|
|
(Container : List)
|
|
return List_Iterator_Interfaces.Reversible_Iterator'Class
|
|
is
|
|
begin
|
|
-- The value of the Node component influences the behavior of the First
|
|
-- and Last selector functions of the iterator object. When the Node
|
|
-- component is 0 (as is the case here), this means the iterator
|
|
-- object was constructed without a start expression. This is a
|
|
-- complete iterator, meaning that the iteration starts from the
|
|
-- (logical) beginning of the sequence of items.
|
|
|
|
-- Note: For a forward iterator, Container.First is the beginning, and
|
|
-- for a reverse iterator, Container.Last is the beginning.
|
|
|
|
return It : constant Iterator :=
|
|
Iterator'(Limited_Controlled with
|
|
Container => Container'Unrestricted_Access,
|
|
Node => 0)
|
|
do
|
|
Busy (Container.TC'Unrestricted_Access.all);
|
|
end return;
|
|
end Iterate;
|
|
|
|
function Iterate
|
|
(Container : List;
|
|
Start : Cursor)
|
|
return List_Iterator_Interfaces.Reversible_Iterator'class
|
|
is
|
|
begin
|
|
-- It was formerly the case that when Start = No_Element, the partial
|
|
-- iterator was defined to behave the same as for a complete iterator,
|
|
-- and iterate over the entire sequence of items. However, those
|
|
-- semantics were unintuitive and arguably error-prone (it is too easy
|
|
-- to accidentally create an endless loop), and so they were changed,
|
|
-- per the ARG meeting in Denver on 2011/11. However, there was no
|
|
-- consensus about what positive meaning this corner case should have,
|
|
-- and so it was decided to simply raise an exception. This does imply,
|
|
-- however, that it is not possible to use a partial iterator to specify
|
|
-- an empty sequence of items.
|
|
|
|
if Checks and then Start = No_Element then
|
|
raise Constraint_Error with
|
|
"Start position for iterator equals No_Element";
|
|
end if;
|
|
|
|
if Checks and then Start.Container /= Container'Unrestricted_Access then
|
|
raise Program_Error with
|
|
"Start cursor of Iterate designates wrong list";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Start), "Start cursor of Iterate is bad");
|
|
|
|
-- The value of the Node component influences the behavior of the First
|
|
-- and Last selector functions of the iterator object. When the Node
|
|
-- component is positive (as is the case here), it means that this
|
|
-- is a partial iteration, over a subset of the complete sequence of
|
|
-- items. The iterator object was constructed with a start expression,
|
|
-- indicating the position from which the iteration begins. Note that
|
|
-- the start position has the same value irrespective of whether this
|
|
-- is a forward or reverse iteration.
|
|
|
|
return It : constant Iterator :=
|
|
Iterator'(Limited_Controlled with
|
|
Container => Container'Unrestricted_Access,
|
|
Node => Start.Node)
|
|
do
|
|
Busy (Container.TC'Unrestricted_Access.all);
|
|
end return;
|
|
end Iterate;
|
|
|
|
----------
|
|
-- Last --
|
|
----------
|
|
|
|
function Last (Container : List) return Cursor is
|
|
begin
|
|
if Container.Last = 0 then
|
|
return No_Element;
|
|
else
|
|
return Cursor'(Container'Unrestricted_Access, Container.Last);
|
|
end if;
|
|
end Last;
|
|
|
|
function Last (Object : Iterator) return Cursor is
|
|
begin
|
|
-- The value of the iterator object's Node component influences the
|
|
-- behavior of the Last (and First) selector function.
|
|
|
|
-- When the Node component is 0, this means the iterator object was
|
|
-- constructed without a start expression, in which case the (reverse)
|
|
-- iteration starts from the (logical) beginning of the entire sequence
|
|
-- (corresponding to Container.Last, for a reverse iterator).
|
|
|
|
-- Otherwise, this is iteration over a partial sequence of items. When
|
|
-- the Node component is positive, the iterator object was constructed
|
|
-- with a start expression, that specifies the position from which the
|
|
-- (reverse) partial iteration begins.
|
|
|
|
if Object.Node = 0 then
|
|
return Bounded_Doubly_Linked_Lists.Last (Object.Container.all);
|
|
else
|
|
return Cursor'(Object.Container, Object.Node);
|
|
end if;
|
|
end Last;
|
|
|
|
------------------
|
|
-- Last_Element --
|
|
------------------
|
|
|
|
function Last_Element (Container : List) return Element_Type is
|
|
begin
|
|
if Checks and then Container.Last = 0 then
|
|
raise Constraint_Error with "list is empty";
|
|
end if;
|
|
|
|
return Container.Nodes (Container.Last).Element;
|
|
end Last_Element;
|
|
|
|
------------
|
|
-- Length --
|
|
------------
|
|
|
|
function Length (Container : List) return Count_Type is
|
|
begin
|
|
return Container.Length;
|
|
end Length;
|
|
|
|
----------
|
|
-- Move --
|
|
----------
|
|
|
|
procedure Move
|
|
(Target : in out List;
|
|
Source : in out List)
|
|
is
|
|
N : Node_Array renames Source.Nodes;
|
|
X : Count_Type;
|
|
|
|
begin
|
|
if Target'Address = Source'Address then
|
|
return;
|
|
end if;
|
|
|
|
if Checks and then Target.Capacity < Source.Length then
|
|
raise Capacity_Error with "Source length exceeds Target capacity";
|
|
end if;
|
|
|
|
TC_Check (Source.TC);
|
|
|
|
-- Clear target, note that this checks busy bits of Target
|
|
|
|
Clear (Target);
|
|
|
|
while Source.Length > 1 loop
|
|
pragma Assert (Source.First in 1 .. Source.Capacity);
|
|
pragma Assert (Source.Last /= Source.First);
|
|
pragma Assert (N (Source.First).Prev = 0);
|
|
pragma Assert (N (Source.Last).Next = 0);
|
|
|
|
-- Copy first element from Source to Target
|
|
|
|
X := Source.First;
|
|
Append (Target, N (X).Element);
|
|
|
|
-- Unlink first node of Source
|
|
|
|
Source.First := N (X).Next;
|
|
N (Source.First).Prev := 0;
|
|
|
|
Source.Length := Source.Length - 1;
|
|
|
|
-- The representation invariants for Source have been restored. It is
|
|
-- now safe to free the unlinked node, without fear of corrupting the
|
|
-- active links of Source.
|
|
|
|
-- Note that the algorithm we use here models similar algorithms used
|
|
-- in the unbounded form of the doubly-linked list container. In that
|
|
-- case, Free is an instantation of Unchecked_Deallocation, which can
|
|
-- fail (because PE will be raised if controlled Finalize fails), so
|
|
-- we must defer the call until the last step. Here in the bounded
|
|
-- form, Free merely links the node we have just "deallocated" onto a
|
|
-- list of inactive nodes, so technically Free cannot fail. However,
|
|
-- for consistency, we handle Free the same way here as we do for the
|
|
-- unbounded form, with the pessimistic assumption that it can fail.
|
|
|
|
Free (Source, X);
|
|
end loop;
|
|
|
|
if Source.Length = 1 then
|
|
pragma Assert (Source.First in 1 .. Source.Capacity);
|
|
pragma Assert (Source.Last = Source.First);
|
|
pragma Assert (N (Source.First).Prev = 0);
|
|
pragma Assert (N (Source.Last).Next = 0);
|
|
|
|
-- Copy element from Source to Target
|
|
|
|
X := Source.First;
|
|
Append (Target, N (X).Element);
|
|
|
|
-- Unlink node of Source
|
|
|
|
Source.First := 0;
|
|
Source.Last := 0;
|
|
Source.Length := 0;
|
|
|
|
-- Return the unlinked node to the free store
|
|
|
|
Free (Source, X);
|
|
end if;
|
|
end Move;
|
|
|
|
----------
|
|
-- Next --
|
|
----------
|
|
|
|
procedure Next (Position : in out Cursor) is
|
|
begin
|
|
Position := Next (Position);
|
|
end Next;
|
|
|
|
function Next (Position : Cursor) return Cursor is
|
|
begin
|
|
if Position.Node = 0 then
|
|
return No_Element;
|
|
end if;
|
|
|
|
pragma Assert (Vet (Position), "bad cursor in Next");
|
|
|
|
declare
|
|
Nodes : Node_Array renames Position.Container.Nodes;
|
|
Node : constant Count_Type := Nodes (Position.Node).Next;
|
|
begin
|
|
if Node = 0 then
|
|
return No_Element;
|
|
else
|
|
return Cursor'(Position.Container, Node);
|
|
end if;
|
|
end;
|
|
end Next;
|
|
|
|
function Next
|
|
(Object : Iterator;
|
|
Position : Cursor) return Cursor
|
|
is
|
|
begin
|
|
if Position.Container = null then
|
|
return No_Element;
|
|
end if;
|
|
|
|
if Checks and then Position.Container /= Object.Container then
|
|
raise Program_Error with
|
|
"Position cursor of Next designates wrong list";
|
|
end if;
|
|
|
|
return Next (Position);
|
|
end Next;
|
|
|
|
-------------
|
|
-- Prepend --
|
|
-------------
|
|
|
|
procedure Prepend
|
|
(Container : in out List;
|
|
New_Item : Element_Type;
|
|
Count : Count_Type := 1)
|
|
is
|
|
begin
|
|
Insert (Container, First (Container), New_Item, Count);
|
|
end Prepend;
|
|
|
|
--------------
|
|
-- Previous --
|
|
--------------
|
|
|
|
procedure Previous (Position : in out Cursor) is
|
|
begin
|
|
Position := Previous (Position);
|
|
end Previous;
|
|
|
|
function Previous (Position : Cursor) return Cursor is
|
|
begin
|
|
if Position.Node = 0 then
|
|
return No_Element;
|
|
end if;
|
|
|
|
pragma Assert (Vet (Position), "bad cursor in Previous");
|
|
|
|
declare
|
|
Nodes : Node_Array renames Position.Container.Nodes;
|
|
Node : constant Count_Type := Nodes (Position.Node).Prev;
|
|
begin
|
|
if Node = 0 then
|
|
return No_Element;
|
|
else
|
|
return Cursor'(Position.Container, Node);
|
|
end if;
|
|
end;
|
|
end Previous;
|
|
|
|
function Previous
|
|
(Object : Iterator;
|
|
Position : Cursor) return Cursor
|
|
is
|
|
begin
|
|
if Position.Container = null then
|
|
return No_Element;
|
|
end if;
|
|
|
|
if Checks and then Position.Container /= Object.Container then
|
|
raise Program_Error with
|
|
"Position cursor of Previous designates wrong list";
|
|
end if;
|
|
|
|
return Previous (Position);
|
|
end Previous;
|
|
|
|
----------------------
|
|
-- Pseudo_Reference --
|
|
----------------------
|
|
|
|
function Pseudo_Reference
|
|
(Container : aliased List'Class) return Reference_Control_Type
|
|
is
|
|
TC : constant Tamper_Counts_Access := Container.TC'Unrestricted_Access;
|
|
begin
|
|
return R : constant Reference_Control_Type := (Controlled with TC) do
|
|
Lock (TC.all);
|
|
end return;
|
|
end Pseudo_Reference;
|
|
|
|
-------------------
|
|
-- Query_Element --
|
|
-------------------
|
|
|
|
procedure Query_Element
|
|
(Position : Cursor;
|
|
Process : not null access procedure (Element : Element_Type))
|
|
is
|
|
begin
|
|
if Checks and then Position.Node = 0 then
|
|
raise Constraint_Error with
|
|
"Position cursor has no element";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Position), "bad cursor in Query_Element");
|
|
|
|
declare
|
|
Lock : With_Lock (Position.Container.TC'Unrestricted_Access);
|
|
C : List renames Position.Container.all'Unrestricted_Access.all;
|
|
N : Node_Type renames C.Nodes (Position.Node);
|
|
begin
|
|
Process (N.Element);
|
|
end;
|
|
end Query_Element;
|
|
|
|
----------
|
|
-- Read --
|
|
----------
|
|
|
|
procedure Read
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : out List)
|
|
is
|
|
N : Count_Type'Base;
|
|
X : Count_Type;
|
|
|
|
begin
|
|
Clear (Item);
|
|
Count_Type'Base'Read (Stream, N);
|
|
|
|
if Checks and then N < 0 then
|
|
raise Program_Error with "bad list length (corrupt stream)";
|
|
end if;
|
|
|
|
if N = 0 then
|
|
return;
|
|
end if;
|
|
|
|
if Checks and then N > Item.Capacity then
|
|
raise Constraint_Error with "length exceeds capacity";
|
|
end if;
|
|
|
|
for Idx in 1 .. N loop
|
|
Allocate (Item, Stream, New_Node => X);
|
|
Insert_Internal (Item, Before => 0, New_Node => X);
|
|
end loop;
|
|
end Read;
|
|
|
|
procedure Read
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : out Cursor)
|
|
is
|
|
begin
|
|
raise Program_Error with "attempt to stream list cursor";
|
|
end Read;
|
|
|
|
procedure Read
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : out Reference_Type)
|
|
is
|
|
begin
|
|
raise Program_Error with "attempt to stream reference";
|
|
end Read;
|
|
|
|
procedure Read
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : out Constant_Reference_Type)
|
|
is
|
|
begin
|
|
raise Program_Error with "attempt to stream reference";
|
|
end Read;
|
|
|
|
---------------
|
|
-- Reference --
|
|
---------------
|
|
|
|
function Reference
|
|
(Container : aliased in out List;
|
|
Position : Cursor) return Reference_Type
|
|
is
|
|
begin
|
|
if Checks and then Position.Container = null then
|
|
raise Constraint_Error with "Position cursor has no element";
|
|
end if;
|
|
|
|
if Checks and then Position.Container /= Container'Unrestricted_Access
|
|
then
|
|
raise Program_Error with
|
|
"Position cursor designates wrong container";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Position), "bad cursor in function Reference");
|
|
|
|
declare
|
|
N : Node_Type renames Container.Nodes (Position.Node);
|
|
TC : constant Tamper_Counts_Access :=
|
|
Container.TC'Unrestricted_Access;
|
|
begin
|
|
return R : constant Reference_Type :=
|
|
(Element => N.Element'Access,
|
|
Control => (Controlled with TC))
|
|
do
|
|
Lock (TC.all);
|
|
end return;
|
|
end;
|
|
end Reference;
|
|
|
|
---------------------
|
|
-- Replace_Element --
|
|
---------------------
|
|
|
|
procedure Replace_Element
|
|
(Container : in out List;
|
|
Position : Cursor;
|
|
New_Item : Element_Type)
|
|
is
|
|
begin
|
|
if Checks and then Position.Container = null then
|
|
raise Constraint_Error with "Position cursor has no element";
|
|
end if;
|
|
|
|
if Checks and then Position.Container /= Container'Unchecked_Access then
|
|
raise Program_Error with
|
|
"Position cursor designates wrong container";
|
|
end if;
|
|
|
|
TE_Check (Container.TC);
|
|
|
|
pragma Assert (Vet (Position), "bad cursor in Replace_Element");
|
|
|
|
Container.Nodes (Position.Node).Element := New_Item;
|
|
end Replace_Element;
|
|
|
|
----------------------
|
|
-- Reverse_Elements --
|
|
----------------------
|
|
|
|
procedure Reverse_Elements (Container : in out List) is
|
|
N : Node_Array renames Container.Nodes;
|
|
I : Count_Type := Container.First;
|
|
J : Count_Type := Container.Last;
|
|
|
|
procedure Swap (L, R : Count_Type);
|
|
|
|
----------
|
|
-- Swap --
|
|
----------
|
|
|
|
procedure Swap (L, R : Count_Type) is
|
|
LN : constant Count_Type := N (L).Next;
|
|
LP : constant Count_Type := N (L).Prev;
|
|
|
|
RN : constant Count_Type := N (R).Next;
|
|
RP : constant Count_Type := N (R).Prev;
|
|
|
|
begin
|
|
if LP /= 0 then
|
|
N (LP).Next := R;
|
|
end if;
|
|
|
|
if RN /= 0 then
|
|
N (RN).Prev := L;
|
|
end if;
|
|
|
|
N (L).Next := RN;
|
|
N (R).Prev := LP;
|
|
|
|
if LN = R then
|
|
pragma Assert (RP = L);
|
|
|
|
N (L).Prev := R;
|
|
N (R).Next := L;
|
|
|
|
else
|
|
N (L).Prev := RP;
|
|
N (RP).Next := L;
|
|
|
|
N (R).Next := LN;
|
|
N (LN).Prev := R;
|
|
end if;
|
|
end Swap;
|
|
|
|
-- Start of processing for Reverse_Elements
|
|
|
|
begin
|
|
if Container.Length <= 1 then
|
|
return;
|
|
end if;
|
|
|
|
pragma Assert (N (Container.First).Prev = 0);
|
|
pragma Assert (N (Container.Last).Next = 0);
|
|
|
|
TC_Check (Container.TC);
|
|
|
|
Container.First := J;
|
|
Container.Last := I;
|
|
loop
|
|
Swap (L => I, R => J);
|
|
|
|
J := N (J).Next;
|
|
exit when I = J;
|
|
|
|
I := N (I).Prev;
|
|
exit when I = J;
|
|
|
|
Swap (L => J, R => I);
|
|
|
|
I := N (I).Next;
|
|
exit when I = J;
|
|
|
|
J := N (J).Prev;
|
|
exit when I = J;
|
|
end loop;
|
|
|
|
pragma Assert (N (Container.First).Prev = 0);
|
|
pragma Assert (N (Container.Last).Next = 0);
|
|
end Reverse_Elements;
|
|
|
|
------------------
|
|
-- Reverse_Find --
|
|
------------------
|
|
|
|
function Reverse_Find
|
|
(Container : List;
|
|
Item : Element_Type;
|
|
Position : Cursor := No_Element) return Cursor
|
|
is
|
|
Node : Count_Type := Position.Node;
|
|
|
|
begin
|
|
if Node = 0 then
|
|
Node := Container.Last;
|
|
|
|
else
|
|
if Checks and then Position.Container /= Container'Unrestricted_Access
|
|
then
|
|
raise Program_Error with
|
|
"Position cursor designates wrong container";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Position), "bad cursor in Reverse_Find");
|
|
end if;
|
|
|
|
-- Per AI05-0022, the container implementation is required to detect
|
|
-- element tampering by a generic actual subprogram.
|
|
|
|
declare
|
|
Lock : With_Lock (Container.TC'Unrestricted_Access);
|
|
begin
|
|
while Node /= 0 loop
|
|
if Container.Nodes (Node).Element = Item then
|
|
return Cursor'(Container'Unrestricted_Access, Node);
|
|
end if;
|
|
|
|
Node := Container.Nodes (Node).Prev;
|
|
end loop;
|
|
|
|
return No_Element;
|
|
end;
|
|
end Reverse_Find;
|
|
|
|
---------------------
|
|
-- Reverse_Iterate --
|
|
---------------------
|
|
|
|
procedure Reverse_Iterate
|
|
(Container : List;
|
|
Process : not null access procedure (Position : Cursor))
|
|
is
|
|
Busy : With_Busy (Container.TC'Unrestricted_Access);
|
|
Node : Count_Type := Container.Last;
|
|
|
|
begin
|
|
while Node /= 0 loop
|
|
Process (Cursor'(Container'Unrestricted_Access, Node));
|
|
Node := Container.Nodes (Node).Prev;
|
|
end loop;
|
|
end Reverse_Iterate;
|
|
|
|
------------
|
|
-- Splice --
|
|
------------
|
|
|
|
procedure Splice
|
|
(Target : in out List;
|
|
Before : Cursor;
|
|
Source : in out List)
|
|
is
|
|
begin
|
|
if Before.Container /= null then
|
|
if Checks and then Before.Container /= Target'Unrestricted_Access then
|
|
raise Program_Error with
|
|
"Before cursor designates wrong container";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Before), "bad cursor in Splice");
|
|
end if;
|
|
|
|
if Target'Address = Source'Address or else Source.Length = 0 then
|
|
return;
|
|
end if;
|
|
|
|
if Checks and then Target.Length > Count_Type'Last - Source.Length then
|
|
raise Constraint_Error with "new length exceeds maximum";
|
|
end if;
|
|
|
|
if Checks and then Target.Length + Source.Length > Target.Capacity then
|
|
raise Capacity_Error with "new length exceeds target capacity";
|
|
end if;
|
|
|
|
TC_Check (Target.TC);
|
|
TC_Check (Source.TC);
|
|
|
|
Splice_Internal (Target, Before.Node, Source);
|
|
end Splice;
|
|
|
|
procedure Splice
|
|
(Container : in out List;
|
|
Before : Cursor;
|
|
Position : Cursor)
|
|
is
|
|
N : Node_Array renames Container.Nodes;
|
|
|
|
begin
|
|
if Before.Container /= null then
|
|
if Checks and then Before.Container /= Container'Unchecked_Access then
|
|
raise Program_Error with
|
|
"Before cursor designates wrong container";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Before), "bad Before cursor in Splice");
|
|
end if;
|
|
|
|
if Checks and then Position.Node = 0 then
|
|
raise Constraint_Error with "Position cursor has no element";
|
|
end if;
|
|
|
|
if Checks and then Position.Container /= Container'Unrestricted_Access
|
|
then
|
|
raise Program_Error with
|
|
"Position cursor designates wrong container";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Position), "bad Position cursor in Splice");
|
|
|
|
if Position.Node = Before.Node
|
|
or else N (Position.Node).Next = Before.Node
|
|
then
|
|
return;
|
|
end if;
|
|
|
|
pragma Assert (Container.Length >= 2);
|
|
|
|
TC_Check (Container.TC);
|
|
|
|
if Before.Node = 0 then
|
|
pragma Assert (Position.Node /= Container.Last);
|
|
|
|
if Position.Node = Container.First then
|
|
Container.First := N (Position.Node).Next;
|
|
N (Container.First).Prev := 0;
|
|
else
|
|
N (N (Position.Node).Prev).Next := N (Position.Node).Next;
|
|
N (N (Position.Node).Next).Prev := N (Position.Node).Prev;
|
|
end if;
|
|
|
|
N (Container.Last).Next := Position.Node;
|
|
N (Position.Node).Prev := Container.Last;
|
|
|
|
Container.Last := Position.Node;
|
|
N (Container.Last).Next := 0;
|
|
|
|
return;
|
|
end if;
|
|
|
|
if Before.Node = Container.First then
|
|
pragma Assert (Position.Node /= Container.First);
|
|
|
|
if Position.Node = Container.Last then
|
|
Container.Last := N (Position.Node).Prev;
|
|
N (Container.Last).Next := 0;
|
|
else
|
|
N (N (Position.Node).Prev).Next := N (Position.Node).Next;
|
|
N (N (Position.Node).Next).Prev := N (Position.Node).Prev;
|
|
end if;
|
|
|
|
N (Container.First).Prev := Position.Node;
|
|
N (Position.Node).Next := Container.First;
|
|
|
|
Container.First := Position.Node;
|
|
N (Container.First).Prev := 0;
|
|
|
|
return;
|
|
end if;
|
|
|
|
if Position.Node = Container.First then
|
|
Container.First := N (Position.Node).Next;
|
|
N (Container.First).Prev := 0;
|
|
|
|
elsif Position.Node = Container.Last then
|
|
Container.Last := N (Position.Node).Prev;
|
|
N (Container.Last).Next := 0;
|
|
|
|
else
|
|
N (N (Position.Node).Prev).Next := N (Position.Node).Next;
|
|
N (N (Position.Node).Next).Prev := N (Position.Node).Prev;
|
|
end if;
|
|
|
|
N (N (Before.Node).Prev).Next := Position.Node;
|
|
N (Position.Node).Prev := N (Before.Node).Prev;
|
|
|
|
N (Before.Node).Prev := Position.Node;
|
|
N (Position.Node).Next := Before.Node;
|
|
|
|
pragma Assert (N (Container.First).Prev = 0);
|
|
pragma Assert (N (Container.Last).Next = 0);
|
|
end Splice;
|
|
|
|
procedure Splice
|
|
(Target : in out List;
|
|
Before : Cursor;
|
|
Source : in out List;
|
|
Position : in out Cursor)
|
|
is
|
|
Target_Position : Count_Type;
|
|
|
|
begin
|
|
if Target'Address = Source'Address then
|
|
Splice (Target, Before, Position);
|
|
return;
|
|
end if;
|
|
|
|
if Before.Container /= null then
|
|
if Checks and then Before.Container /= Target'Unrestricted_Access then
|
|
raise Program_Error with
|
|
"Before cursor designates wrong container";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Before), "bad Before cursor in Splice");
|
|
end if;
|
|
|
|
if Checks and then Position.Node = 0 then
|
|
raise Constraint_Error with "Position cursor has no element";
|
|
end if;
|
|
|
|
if Checks and then Position.Container /= Source'Unrestricted_Access then
|
|
raise Program_Error with
|
|
"Position cursor designates wrong container";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Position), "bad Position cursor in Splice");
|
|
|
|
if Checks and then Target.Length >= Target.Capacity then
|
|
raise Capacity_Error with "Target is full";
|
|
end if;
|
|
|
|
TC_Check (Target.TC);
|
|
TC_Check (Source.TC);
|
|
|
|
Splice_Internal
|
|
(Target => Target,
|
|
Before => Before.Node,
|
|
Source => Source,
|
|
Src_Pos => Position.Node,
|
|
Tgt_Pos => Target_Position);
|
|
|
|
Position := Cursor'(Target'Unrestricted_Access, Target_Position);
|
|
end Splice;
|
|
|
|
---------------------
|
|
-- Splice_Internal --
|
|
---------------------
|
|
|
|
procedure Splice_Internal
|
|
(Target : in out List;
|
|
Before : Count_Type;
|
|
Source : in out List)
|
|
is
|
|
N : Node_Array renames Source.Nodes;
|
|
X : Count_Type;
|
|
|
|
begin
|
|
-- This implements the corresponding Splice operation, after the
|
|
-- parameters have been vetted, and corner-cases disposed of.
|
|
|
|
pragma Assert (Target'Address /= Source'Address);
|
|
pragma Assert (Source.Length > 0);
|
|
pragma Assert (Source.First /= 0);
|
|
pragma Assert (N (Source.First).Prev = 0);
|
|
pragma Assert (Source.Last /= 0);
|
|
pragma Assert (N (Source.Last).Next = 0);
|
|
pragma Assert (Target.Length <= Count_Type'Last - Source.Length);
|
|
pragma Assert (Target.Length + Source.Length <= Target.Capacity);
|
|
|
|
while Source.Length > 1 loop
|
|
-- Copy first element of Source onto Target
|
|
|
|
Allocate (Target, N (Source.First).Element, New_Node => X);
|
|
Insert_Internal (Target, Before => Before, New_Node => X);
|
|
|
|
-- Unlink the first node from Source
|
|
|
|
X := Source.First;
|
|
pragma Assert (N (N (X).Next).Prev = X);
|
|
|
|
Source.First := N (X).Next;
|
|
N (Source.First).Prev := 0;
|
|
|
|
Source.Length := Source.Length - 1;
|
|
|
|
-- Return the Source node to its free store
|
|
|
|
Free (Source, X);
|
|
end loop;
|
|
|
|
-- Copy first (and only remaining) element of Source onto Target
|
|
|
|
Allocate (Target, N (Source.First).Element, New_Node => X);
|
|
Insert_Internal (Target, Before => Before, New_Node => X);
|
|
|
|
-- Unlink the node from Source
|
|
|
|
X := Source.First;
|
|
pragma Assert (X = Source.Last);
|
|
|
|
Source.First := 0;
|
|
Source.Last := 0;
|
|
|
|
Source.Length := 0;
|
|
|
|
-- Return the Source node to its free store
|
|
|
|
Free (Source, X);
|
|
end Splice_Internal;
|
|
|
|
procedure Splice_Internal
|
|
(Target : in out List;
|
|
Before : Count_Type; -- node of Target
|
|
Source : in out List;
|
|
Src_Pos : Count_Type; -- node of Source
|
|
Tgt_Pos : out Count_Type)
|
|
is
|
|
N : Node_Array renames Source.Nodes;
|
|
|
|
begin
|
|
-- This implements the corresponding Splice operation, after the
|
|
-- parameters have been vetted, and corner-cases handled.
|
|
|
|
pragma Assert (Target'Address /= Source'Address);
|
|
pragma Assert (Target.Length < Target.Capacity);
|
|
pragma Assert (Source.Length > 0);
|
|
pragma Assert (Source.First /= 0);
|
|
pragma Assert (N (Source.First).Prev = 0);
|
|
pragma Assert (Source.Last /= 0);
|
|
pragma Assert (N (Source.Last).Next = 0);
|
|
pragma Assert (Src_Pos /= 0);
|
|
|
|
Allocate (Target, N (Src_Pos).Element, New_Node => Tgt_Pos);
|
|
Insert_Internal (Target, Before => Before, New_Node => Tgt_Pos);
|
|
|
|
if Source.Length = 1 then
|
|
pragma Assert (Source.First = Source.Last);
|
|
pragma Assert (Src_Pos = Source.First);
|
|
|
|
Source.First := 0;
|
|
Source.Last := 0;
|
|
|
|
elsif Src_Pos = Source.First then
|
|
pragma Assert (N (N (Src_Pos).Next).Prev = Src_Pos);
|
|
|
|
Source.First := N (Src_Pos).Next;
|
|
N (Source.First).Prev := 0;
|
|
|
|
elsif Src_Pos = Source.Last then
|
|
pragma Assert (N (N (Src_Pos).Prev).Next = Src_Pos);
|
|
|
|
Source.Last := N (Src_Pos).Prev;
|
|
N (Source.Last).Next := 0;
|
|
|
|
else
|
|
pragma Assert (Source.Length >= 3);
|
|
pragma Assert (N (N (Src_Pos).Next).Prev = Src_Pos);
|
|
pragma Assert (N (N (Src_Pos).Prev).Next = Src_Pos);
|
|
|
|
N (N (Src_Pos).Next).Prev := N (Src_Pos).Prev;
|
|
N (N (Src_Pos).Prev).Next := N (Src_Pos).Next;
|
|
end if;
|
|
|
|
Source.Length := Source.Length - 1;
|
|
Free (Source, Src_Pos);
|
|
end Splice_Internal;
|
|
|
|
----------
|
|
-- Swap --
|
|
----------
|
|
|
|
procedure Swap
|
|
(Container : in out List;
|
|
I, J : Cursor)
|
|
is
|
|
begin
|
|
if Checks and then I.Node = 0 then
|
|
raise Constraint_Error with "I cursor has no element";
|
|
end if;
|
|
|
|
if Checks and then J.Node = 0 then
|
|
raise Constraint_Error with "J cursor has no element";
|
|
end if;
|
|
|
|
if Checks and then I.Container /= Container'Unchecked_Access then
|
|
raise Program_Error with "I cursor designates wrong container";
|
|
end if;
|
|
|
|
if Checks and then J.Container /= Container'Unchecked_Access then
|
|
raise Program_Error with "J cursor designates wrong container";
|
|
end if;
|
|
|
|
if I.Node = J.Node then
|
|
return;
|
|
end if;
|
|
|
|
TE_Check (Container.TC);
|
|
|
|
pragma Assert (Vet (I), "bad I cursor in Swap");
|
|
pragma Assert (Vet (J), "bad J cursor in Swap");
|
|
|
|
declare
|
|
EI : Element_Type renames Container.Nodes (I.Node).Element;
|
|
EJ : Element_Type renames Container.Nodes (J.Node).Element;
|
|
|
|
EI_Copy : constant Element_Type := EI;
|
|
|
|
begin
|
|
EI := EJ;
|
|
EJ := EI_Copy;
|
|
end;
|
|
end Swap;
|
|
|
|
----------------
|
|
-- Swap_Links --
|
|
----------------
|
|
|
|
procedure Swap_Links
|
|
(Container : in out List;
|
|
I, J : Cursor)
|
|
is
|
|
begin
|
|
if Checks and then I.Node = 0 then
|
|
raise Constraint_Error with "I cursor has no element";
|
|
end if;
|
|
|
|
if Checks and then J.Node = 0 then
|
|
raise Constraint_Error with "J cursor has no element";
|
|
end if;
|
|
|
|
if Checks and then I.Container /= Container'Unrestricted_Access then
|
|
raise Program_Error with "I cursor designates wrong container";
|
|
end if;
|
|
|
|
if Checks and then J.Container /= Container'Unrestricted_Access then
|
|
raise Program_Error with "J cursor designates wrong container";
|
|
end if;
|
|
|
|
if I.Node = J.Node then
|
|
return;
|
|
end if;
|
|
|
|
TC_Check (Container.TC);
|
|
|
|
pragma Assert (Vet (I), "bad I cursor in Swap_Links");
|
|
pragma Assert (Vet (J), "bad J cursor in Swap_Links");
|
|
|
|
declare
|
|
I_Next : constant Cursor := Next (I);
|
|
|
|
begin
|
|
if I_Next = J then
|
|
Splice (Container, Before => I, Position => J);
|
|
|
|
else
|
|
declare
|
|
J_Next : constant Cursor := Next (J);
|
|
|
|
begin
|
|
if J_Next = I then
|
|
Splice (Container, Before => J, Position => I);
|
|
|
|
else
|
|
pragma Assert (Container.Length >= 3);
|
|
|
|
Splice (Container, Before => I_Next, Position => J);
|
|
Splice (Container, Before => J_Next, Position => I);
|
|
end if;
|
|
end;
|
|
end if;
|
|
end;
|
|
end Swap_Links;
|
|
|
|
--------------------
|
|
-- Update_Element --
|
|
--------------------
|
|
|
|
procedure Update_Element
|
|
(Container : in out List;
|
|
Position : Cursor;
|
|
Process : not null access procedure (Element : in out Element_Type))
|
|
is
|
|
begin
|
|
if Checks and then Position.Node = 0 then
|
|
raise Constraint_Error with "Position cursor has no element";
|
|
end if;
|
|
|
|
if Checks and then Position.Container /= Container'Unchecked_Access then
|
|
raise Program_Error with
|
|
"Position cursor designates wrong container";
|
|
end if;
|
|
|
|
pragma Assert (Vet (Position), "bad cursor in Update_Element");
|
|
|
|
declare
|
|
Lock : With_Lock (Container.TC'Unchecked_Access);
|
|
N : Node_Type renames Container.Nodes (Position.Node);
|
|
begin
|
|
Process (N.Element);
|
|
end;
|
|
end Update_Element;
|
|
|
|
---------
|
|
-- Vet --
|
|
---------
|
|
|
|
function Vet (Position : Cursor) return Boolean is
|
|
begin
|
|
if Position.Node = 0 then
|
|
return Position.Container = null;
|
|
end if;
|
|
|
|
if Position.Container = null then
|
|
return False;
|
|
end if;
|
|
|
|
declare
|
|
L : List renames Position.Container.all;
|
|
N : Node_Array renames L.Nodes;
|
|
|
|
begin
|
|
if L.Length = 0 then
|
|
return False;
|
|
end if;
|
|
|
|
if L.First = 0 or L.First > L.Capacity then
|
|
return False;
|
|
end if;
|
|
|
|
if L.Last = 0 or L.Last > L.Capacity then
|
|
return False;
|
|
end if;
|
|
|
|
if N (L.First).Prev /= 0 then
|
|
return False;
|
|
end if;
|
|
|
|
if N (L.Last).Next /= 0 then
|
|
return False;
|
|
end if;
|
|
|
|
if Position.Node > L.Capacity then
|
|
return False;
|
|
end if;
|
|
|
|
-- An invariant of an active node is that its Previous and Next
|
|
-- components are non-negative. Operation Free sets the Previous
|
|
-- component of the node to the value -1 before actually deallocating
|
|
-- the node, to mark the node as inactive. (By "dellocating" we mean
|
|
-- only that the node is linked onto a list of inactive nodes used
|
|
-- for storage.) This marker gives us a simple way to detect a
|
|
-- dangling reference to a node.
|
|
|
|
if N (Position.Node).Prev < 0 then -- see Free
|
|
return False;
|
|
end if;
|
|
|
|
if N (Position.Node).Prev > L.Capacity then
|
|
return False;
|
|
end if;
|
|
|
|
if N (Position.Node).Next = Position.Node then
|
|
return False;
|
|
end if;
|
|
|
|
if N (Position.Node).Prev = Position.Node then
|
|
return False;
|
|
end if;
|
|
|
|
if N (Position.Node).Prev = 0
|
|
and then Position.Node /= L.First
|
|
then
|
|
return False;
|
|
end if;
|
|
|
|
pragma Assert (N (Position.Node).Prev /= 0
|
|
or else Position.Node = L.First);
|
|
|
|
if N (Position.Node).Next = 0
|
|
and then Position.Node /= L.Last
|
|
then
|
|
return False;
|
|
end if;
|
|
|
|
pragma Assert (N (Position.Node).Next /= 0
|
|
or else Position.Node = L.Last);
|
|
|
|
if L.Length = 1 then
|
|
return L.First = L.Last;
|
|
end if;
|
|
|
|
if L.First = L.Last then
|
|
return False;
|
|
end if;
|
|
|
|
if N (L.First).Next = 0 then
|
|
return False;
|
|
end if;
|
|
|
|
if N (L.Last).Prev = 0 then
|
|
return False;
|
|
end if;
|
|
|
|
if N (N (L.First).Next).Prev /= L.First then
|
|
return False;
|
|
end if;
|
|
|
|
if N (N (L.Last).Prev).Next /= L.Last then
|
|
return False;
|
|
end if;
|
|
|
|
if L.Length = 2 then
|
|
if N (L.First).Next /= L.Last then
|
|
return False;
|
|
end if;
|
|
|
|
if N (L.Last).Prev /= L.First then
|
|
return False;
|
|
end if;
|
|
|
|
return True;
|
|
end if;
|
|
|
|
if N (L.First).Next = L.Last then
|
|
return False;
|
|
end if;
|
|
|
|
if N (L.Last).Prev = L.First then
|
|
return False;
|
|
end if;
|
|
|
|
-- Eliminate earlier possibility
|
|
|
|
if Position.Node = L.First then
|
|
return True;
|
|
end if;
|
|
|
|
pragma Assert (N (Position.Node).Prev /= 0);
|
|
|
|
-- Eliminate another possibility
|
|
|
|
if Position.Node = L.Last then
|
|
return True;
|
|
end if;
|
|
|
|
pragma Assert (N (Position.Node).Next /= 0);
|
|
|
|
if N (N (Position.Node).Next).Prev /= Position.Node then
|
|
return False;
|
|
end if;
|
|
|
|
if N (N (Position.Node).Prev).Next /= Position.Node then
|
|
return False;
|
|
end if;
|
|
|
|
if L.Length = 3 then
|
|
if N (L.First).Next /= Position.Node then
|
|
return False;
|
|
end if;
|
|
|
|
if N (L.Last).Prev /= Position.Node then
|
|
return False;
|
|
end if;
|
|
end if;
|
|
|
|
return True;
|
|
end;
|
|
end Vet;
|
|
|
|
-----------
|
|
-- Write --
|
|
-----------
|
|
|
|
procedure Write
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : List)
|
|
is
|
|
Node : Count_Type;
|
|
|
|
begin
|
|
Count_Type'Base'Write (Stream, Item.Length);
|
|
|
|
Node := Item.First;
|
|
while Node /= 0 loop
|
|
Element_Type'Write (Stream, Item.Nodes (Node).Element);
|
|
Node := Item.Nodes (Node).Next;
|
|
end loop;
|
|
end Write;
|
|
|
|
procedure Write
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : Cursor)
|
|
is
|
|
begin
|
|
raise Program_Error with "attempt to stream list cursor";
|
|
end Write;
|
|
|
|
procedure Write
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : Reference_Type)
|
|
is
|
|
begin
|
|
raise Program_Error with "attempt to stream reference";
|
|
end Write;
|
|
|
|
procedure Write
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : Constant_Reference_Type)
|
|
is
|
|
begin
|
|
raise Program_Error with "attempt to stream reference";
|
|
end Write;
|
|
|
|
end Ada.Containers.Bounded_Doubly_Linked_Lists;
|