------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- ADA.CONTAINERS.RESTRICTED_DOUBLY_LINKED_LISTS --
-- --
-- B o d y --
-- --
-- Copyright (C) 2004-2023, Free Software Foundation, Inc. --
-- --
-- GNAT is free software; you can redistribute it and/or modify it under --
-- terms of the GNU General Public License as published by the Free Soft- --
-- ware Foundation; either version 3, or (at your option) any later ver- --
-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
-- As a special exception under Section 7 of GPL version 3, you are granted --
-- additional permissions described in the GCC Runtime Library Exception, --
-- version 3.1, as published by the Free Software Foundation. --
-- --
-- You should have received a copy of the GNU General Public License and --
-- a copy of the GCC Runtime Library Exception along with this program; --
-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
-- <http://www.gnu.org/licenses/>. --
-- --
-- This unit was originally developed by Matthew J Heaney. --
------------------------------------------------------------------------------
with Ada.Containers.Stable_Sorting; use Ada.Containers.Stable_Sorting;
with System; use type System.Address;
package body Ada.Containers.Restricted_Doubly_Linked_Lists is
-----------------------
-- Local Subprograms --
-----------------------
procedure Allocate
(Container : in out List'Class;
New_Item : Element_Type;
New_Node : out Count_Type);
procedure Free
(Container : in out List'Class;
X : Count_Type);
procedure Insert_Internal
(Container : in out List'Class;
Before : Count_Type;
New_Node : Count_Type);
function Vet (Position : Cursor) return Boolean with Inline;
---------
-- "=" --
---------
function "=" (Left, Right : List) return Boolean is
LN : Node_Array renames Left.Nodes;
RN : Node_Array renames Right.Nodes;
LI : Count_Type := Left.First;
RI : Count_Type := Right.First;
begin
if Left'Address = Right'Address then
return True;
end if;
if Left.Length /= Right.Length then
return False;
end if;
for J in 1 .. Left.Length loop
if LN (LI).Element /= RN (RI).Element then
return False;
end if;
LI := LN (LI).Next;
RI := RN (RI).Next;
end loop;
return True;
end "=";
--------------
-- Allocate --
--------------
procedure Allocate
(Container : in out List'Class;
New_Item : Element_Type;
New_Node : out Count_Type)
is
N : Node_Array renames Container.Nodes;
begin
if Container.Free >= 0 then
New_Node := Container.Free;
N (New_Node).Element := New_Item;
Container.Free := N (New_Node).Next;
else
New_Node := abs Container.Free;
N (New_Node).Element := New_Item;
Container.Free := Container.Free - 1;
end if;
end Allocate;
------------
-- Append --
------------
procedure Append
(Container : in out List;
New_Item : Element_Type;
Count : Count_Type := 1)
is
begin
Insert (Container, No_Element, New_Item, Count);
end Append;
------------
-- Assign --
------------
procedure Assign (Target : in out List; Source : List) is
begin
if Target'Address = Source'Address then
return;
end if;
if Target.Capacity < Source.Length then
raise Constraint_Error; -- ???
end if;
Clear (Target);
declare
N : Node_Array renames Source.Nodes;
J : Count_Type := Source.First;
begin
while J /= 0 loop
Append (Target, N (J).Element);
J := N (J).Next;
end loop;
end;
end Assign;
-----------
-- Clear --
-----------
procedure Clear (Container : in out List) is
N : Node_Array renames Container.Nodes;
X : Count_Type;
begin
if Container.Length = 0 then
pragma Assert (Container.First = 0);
pragma Assert (Container.Last = 0);
-- pragma Assert (Container.Busy = 0);
-- pragma Assert (Container.Lock = 0);
return;
end if;
pragma Assert (Container.First >= 1);
pragma Assert (Container.Last >= 1);
pragma Assert (N (Container.First).Prev = 0);
pragma Assert (N (Container.Last).Next = 0);
-- if Container.Busy > 0 then
-- raise Program_Error;
-- end if;
while Container.Length > 1 loop
X := Container.First;
Container.First := N (X).Next;
N (Container.First).Prev := 0;
Container.Length := Container.Length - 1;
Free (Container, X);
end loop;
X := Container.First;
Container.First := 0;
Container.Last := 0;
Container.Length := 0;
Free (Container, X);
end Clear;
--------------
-- Contains --
--------------
function Contains
(Container : List;
Item : Element_Type) return Boolean
is
begin
return Find (Container, Item) /= No_Element;
end Contains;
------------
-- Delete --
------------
procedure Delete
(Container : in out List;
Position : in out Cursor;
Count : Count_Type := 1)
is
N : Node_Array renames Container.Nodes;
X : Count_Type;
begin
if Position.Node = 0 then
raise Constraint_Error;
end if;
if Position.Container /= Container'Unrestricted_Access then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Delete");
if Position.Node = Container.First then
Delete_First (Container, Count);
Position := No_Element;
return;
end if;
if Count = 0 then
Position := No_Element;
return;
end if;
-- if Container.Busy > 0 then
-- raise Program_Error;
-- end if;
pragma Assert (Container.First >= 1);
pragma Assert (Container.Last >= 1);
pragma Assert (N (Container.First).Prev = 0);
pragma Assert (N (Container.Last).Next = 0);
for Index in 1 .. Count loop
pragma Assert (Container.Length >= 2);
X := Position.Node;
Container.Length := Container.Length - 1;
if X = Container.Last then
Position := No_Element;
Container.Last := N (X).Prev;
N (Container.Last).Next := 0;
Free (Container, X);
return;
end if;
Position.Node := N (X).Next;
N (N (X).Next).Prev := N (X).Prev;
N (N (X).Prev).Next := N (X).Next;
Free (Container, X);
end loop;
Position := No_Element;
end Delete;
------------------
-- Delete_First --
------------------
procedure Delete_First
(Container : in out List;
Count : Count_Type := 1)
is
N : Node_Array renames Container.Nodes;
X : Count_Type;
begin
if Count >= Container.Length then
Clear (Container);
return;
end if;
if Count = 0 then
return;
end if;
-- if Container.Busy > 0 then
-- raise Program_Error;
-- end if;
for I in 1 .. Count loop
X := Container.First;
pragma Assert (N (N (X).Next).Prev = Container.First);
Container.First := N (X).Next;
N (Container.First).Prev := 0;
Container.Length := Container.Length - 1;
Free (Container, X);
end loop;
end Delete_First;
-----------------
-- Delete_Last --
-----------------
procedure Delete_Last
(Container : in out List;
Count : Count_Type := 1)
is
N : Node_Array renames Container.Nodes;
X : Count_Type;
begin
if Count >= Container.Length then
Clear (Container);
return;
end if;
if Count = 0 then
return;
end if;
-- if Container.Busy > 0 then
-- raise Program_Error;
-- end if;
for I in 1 .. Count loop
X := Container.Last;
pragma Assert (N (N (X).Prev).Next = Container.Last);
Container.Last := N (X).Prev;
N (Container.Last).Next := 0;
Container.Length := Container.Length - 1;
Free (Container, X);
end loop;
end Delete_Last;
-------------
-- Element --
-------------
function Element (Position : Cursor) return Element_Type is
begin
if Position.Node = 0 then
raise Constraint_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Element");
declare
N : Node_Array renames Position.Container.Nodes;
begin
return N (Position.Node).Element;
end;
end Element;
----------
-- Find --
----------
function Find
(Container : List;
Item : Element_Type;
Position : Cursor := No_Element) return Cursor
is
Nodes : Node_Array renames Container.Nodes;
Node : Count_Type := Position.Node;
begin
if Node = 0 then
Node := Container.First;
else
if Position.Container /= Container'Unrestricted_Access then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Find");
end if;
while Node /= 0 loop
if Nodes (Node).Element = Item then
return Cursor'(Container'Unrestricted_Access, Node);
end if;
Node := Nodes (Node).Next;
end loop;
return No_Element;
end Find;
-----------
-- First --
-----------
function First (Container : List) return Cursor is
begin
if Container.First = 0 then
return No_Element;
end if;
return Cursor'(Container'Unrestricted_Access, Container.First);
end First;
-------------------
-- First_Element --
-------------------
function First_Element (Container : List) return Element_Type is
N : Node_Array renames Container.Nodes;
begin
if Container.First = 0 then
raise Constraint_Error;
end if;
return N (Container.First).Element;
end First_Element;
----------
-- Free --
----------
procedure Free
(Container : in out List'Class;
X : Count_Type)
is
pragma Assert (X > 0);
pragma Assert (X <= Container.Capacity);
N : Node_Array renames Container.Nodes;
begin
N (X).Prev := -1; -- Node is deallocated (not on active list)
if Container.Free >= 0 then
N (X).Next := Container.Free;
Container.Free := X;
elsif X + 1 = abs Container.Free then
N (X).Next := 0; -- Not strictly necessary, but marginally safer
Container.Free := Container.Free + 1;
else
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
Nodes : Node_Array renames Container.Nodes;
Node : Count_Type := Container.First;
begin
for I 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;
----------
-- Sort --
----------
procedure Sort (Container : in out List) is
N : Node_Array renames Container.Nodes;
begin
if Container.Length <= 1 then
return;
end if;
-- if Container.Busy > 0 then
-- raise Program_Error;
-- end if;
declare
package Descriptors is new List_Descriptors
(Node_Ref => Count_Type, Nil => 0);
use Descriptors;
function Next (Idx : Count_Type) return Count_Type is
(N (Idx).Next);
procedure Set_Next (Idx : Count_Type; Next : Count_Type)
with Inline;
procedure Set_Prev (Idx : Count_Type; Prev : Count_Type)
with Inline;
function "<" (L, R : Count_Type) return Boolean is
(N (L).Element < N (R).Element);
procedure Update_Container (List : List_Descriptor) with Inline;
procedure Set_Next (Idx : Count_Type; Next : Count_Type) is
begin
N (Idx).Next := Next;
end Set_Next;
procedure Set_Prev (Idx : Count_Type; Prev : Count_Type) is
begin
N (Idx).Prev := Prev;
end Set_Prev;
procedure Update_Container (List : List_Descriptor) is
begin
Container.First := List.First;
Container.Last := List.Last;
Container.Length := List.Length;
end Update_Container;
procedure Sort_List is new Doubly_Linked_List_Sort;
begin
Sort_List (List_Descriptor'(First => Container.First,
Last => Container.Last,
Length => Container.Length));
end;
pragma Assert (N (Container.First).Prev = 0);
pragma Assert (N (Container.Last).Next = 0);
end Sort;
end Generic_Sorting;
-----------------
-- 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 Before.Container /= Container'Unrestricted_Access then
raise Program_Error;
end if;
pragma Assert (Vet (Before), "bad cursor in Insert");
end if;
if Count = 0 then
Position := Before;
return;
end if;
if Container.Length > Container.Capacity - Count then
raise Constraint_Error;
end if;
-- if Container.Busy > 0 then
-- raise Program_Error;
-- end if;
Allocate (Container, New_Item, New_Node);
First_Node := New_Node;
Insert_Internal (Container, Before.Node, New_Node);
for Index in 2 .. Count loop
Allocate (Container, New_Item, New_Node);
Insert_Internal (Container, Before.Node, New_Node);
end loop;
Position := Cursor'(Container'Unrestricted_Access, First_Node);
end Insert;
procedure Insert
(Container : in out List;
Before : Cursor;
New_Item : Element_Type;
Count : Count_Type := 1)
is
Position : Cursor;
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; -- Do we need to reinit node ???
pragma Warnings (Off, New_Item);
begin
Insert (Container, Before, New_Item, Position, Count);
end Insert;
---------------------
-- Insert_Internal --
---------------------
procedure Insert_Internal
(Container : in out List'Class;
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;
Container.Last := New_Node;
N (Container.First).Prev := 0;
N (Container.Last).Next := 0;
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;
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
C : List renames Container'Unrestricted_Access.all;
N : Node_Array renames C.Nodes;
-- B : Natural renames C.Busy;
Node : Count_Type := Container.First;
Index : Count_Type := 0;
Index_Max : constant Count_Type := Container.Length;
begin
if Index_Max = 0 then
pragma Assert (Node = 0);
return;
end if;
loop
pragma Assert (Node /= 0);
Process (Cursor'(C'Unchecked_Access, Node));
pragma Assert (Container.Length = Index_Max);
pragma Assert (N (Node).Prev /= -1);
Node := N (Node).Next;
Index := Index + 1;
if Index = Index_Max then
pragma Assert (Node = 0);
return;
end if;
end loop;
end Iterate;
----------
-- Last --
----------
function Last (Container : List) return Cursor is
begin
if Container.Last = 0 then
return No_Element;
end if;
return Cursor'(Container'Unrestricted_Access, Container.Last);
end Last;
------------------
-- Last_Element --
------------------
function Last_Element (Container : List) return Element_Type is
N : Node_Array renames Container.Nodes;
begin
if Container.Last = 0 then
raise Constraint_Error;
end if;
return N (Container.Last).Element;
end Last_Element;
------------
-- Length --
------------
function Length (Container : List) return Count_Type is
begin
return Container.Length;
end Length;
----------
-- 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;
end if;
return Cursor'(Position.Container, Node);
end;
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;
end if;
return Cursor'(Position.Container, Node);
end;
end Previous;
-------------------
-- Query_Element --
-------------------
procedure Query_Element
(Position : Cursor;
Process : not null access procedure (Element : Element_Type))
is
begin
if Position.Node = 0 then
raise Constraint_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Query_Element");
declare
C : List renames Position.Container.all'Unrestricted_Access.all;
N : Node_Type renames C.Nodes (Position.Node);
begin
Process (N.Element);
pragma Assert (N.Prev >= 0);
end;
end Query_Element;
---------------------
-- Replace_Element --
---------------------
procedure Replace_Element
(Container : in out List;
Position : Cursor;
New_Item : Element_Type)
is
begin
if Position.Container = null then
raise Constraint_Error;
end if;
if Position.Container /= Container'Unrestricted_Access then
raise Program_Error;
end if;
-- if Container.Lock > 0 then
-- raise Program_Error;
-- end if;
pragma Assert (Vet (Position), "bad cursor in Replace_Element");
declare
N : Node_Array renames Container.Nodes;
begin
N (Position.Node).Element := New_Item;
end;
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);
-- if Container.Busy > 0 then
-- raise Program_Error;
-- end if;
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
N : Node_Array renames Container.Nodes;
Node : Count_Type := Position.Node;
begin
if Node = 0 then
Node := Container.Last;
else
if Position.Container /= Container'Unrestricted_Access then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Reverse_Find");
end if;
while Node /= 0 loop
if N (Node).Element = Item then
return Cursor'(Container'Unrestricted_Access, Node);
end if;
Node := N (Node).Prev;
end loop;
return No_Element;
end Reverse_Find;
---------------------
-- Reverse_Iterate --
---------------------
procedure Reverse_Iterate
(Container : List;
Process : not null access procedure (Position : Cursor))
is
C : List renames Container'Unrestricted_Access.all;
N : Node_Array renames C.Nodes;
-- B : Natural renames C.Busy;
Node : Count_Type := Container.Last;
Index : Count_Type := 0;
Index_Max : constant Count_Type := Container.Length;
begin
if Index_Max = 0 then
pragma Assert (Node = 0);
return;
end if;
loop
pragma Assert (Node > 0);
Process (Cursor'(C'Unchecked_Access, Node));
pragma Assert (Container.Length = Index_Max);
pragma Assert (N (Node).Prev /= -1);
Node := N (Node).Prev;
Index := Index + 1;
if Index = Index_Max then
pragma Assert (Node = 0);
return;
end if;
end loop;
end Reverse_Iterate;
------------
-- Splice --
------------
procedure Splice
(Container : in out List;
Before : Cursor;
Position : in out Cursor)
is
N : Node_Array renames Container.Nodes;
begin
if Before.Container /= null then
if Before.Container /= Container'Unrestricted_Access then
raise Program_Error;
end if;
pragma Assert (Vet (Before), "bad Before cursor in Splice");
end if;
if Position.Node = 0 then
raise Constraint_Error;
end if;
if Position.Container /= Container'Unrestricted_Access then
raise Program_Error;
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);
-- if Container.Busy > 0 then
-- raise Program_Error;
-- end if;
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;
----------
-- Swap --
----------
procedure Swap
(Container : in out List;
I, J : Cursor)
is
begin
if I.Node = 0
or else J.Node = 0
then
raise Constraint_Error;
end if;
if I.Container /= Container'Unrestricted_Access
or else J.Container /= Container'Unrestricted_Access
then
raise Program_Error;
end if;
if I.Node = J.Node then
return;
end if;
-- if Container.Lock > 0 then
-- raise Program_Error;
-- end if;
pragma Assert (Vet (I), "bad I cursor in Swap");
pragma Assert (Vet (J), "bad J cursor in Swap");
declare
N : Node_Array renames Container.Nodes;
EI : Element_Type renames N (I.Node).Element;
EJ : Element_Type renames N (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 I.Node = 0
or else J.Node = 0
then
raise Constraint_Error;
end if;
if I.Container /= Container'Unrestricted_Access
or else I.Container /= J.Container
then
raise Program_Error;
end if;
if I.Node = J.Node then
return;
end if;
-- if Container.Busy > 0 then
-- raise Program_Error;
-- end if;
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);
J_Copy : Cursor := J;
pragma Warnings (Off, J_Copy);
begin
if I_Next = J then
Splice (Container, Before => I, Position => J_Copy);
else
declare
J_Next : constant Cursor := Next (J);
I_Copy : Cursor := I;
pragma Warnings (Off, I_Copy);
begin
if J_Next = I then
Splice (Container, Before => J, Position => I_Copy);
else
pragma Assert (Container.Length >= 3);
Splice (Container, Before => I_Next, Position => J_Copy);
Splice (Container, Before => J_Next, Position => I_Copy);
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 Position.Node = 0 then
raise Constraint_Error;
end if;
if Position.Container /= Container'Unrestricted_Access then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Update_Element");
declare
N : Node_Type renames Container.Nodes (Position.Node);
begin
Process (N.Element);
pragma Assert (N.Prev >= 0);
end;
end Update_Element;
---------
-- Vet --
---------
function Vet (Position : Cursor) return Boolean is
begin
if not Container_Checks'Enabled then
return True;
end if;
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 then
return False;
end if;
if L.Last = 0 then
return False;
end if;
if Position.Node > L.Capacity then
return False;
end if;
if N (Position.Node).Prev < 0
or else N (Position.Node).Prev > L.Capacity
then
return False;
end if;
if N (Position.Node).Next > 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 N (Position.Node).Prev = 0
and then Position.Node /= L.First
then
return False;
end if;
if N (Position.Node).Next = 0
and then Position.Node /= L.Last
then
return False;
end if;
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;
if Position.Node = L.First then
return True;
end if;
if Position.Node = L.Last then
return True;
end if;
if N (Position.Node).Next = 0 then
return False;
end if;
if N (Position.Node).Prev = 0 then
return False;
end if;
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;
end Ada.Containers.Restricted_Doubly_Linked_Lists;