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------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- A D A . C O N T A I N E R S . --
-- I N D E F I N I T E _ D O U B L Y _ L I N K E D _ L I S T S --
-- --
-- B o d y --
-- --
-- Copyright (C) 2004-2006, Free Software Foundation, Inc. --
-- --
-- This specification is derived from the Ada Reference Manual for use with --
-- GNAT. The copyright notice above, and the license provisions that follow --
-- apply solely to the contents of the part following the private keyword. --
-- --
-- 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 2, 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. See the GNU General Public License --
-- for more details. You should have received a copy of the GNU General --
-- Public License distributed with GNAT; see file COPYING. If not, write --
-- to the Free Software Foundation, 51 Franklin Street, Fifth Floor, --
-- Boston, MA 02110-1301, USA. --
-- --
-- As a special exception, if other files instantiate generics from this --
-- unit, or you link this unit with other files to produce an executable, --
-- this unit does not by itself cause the resulting executable to be --
-- covered by the GNU General Public License. This exception does not --
-- however invalidate any other reasons why the executable file might be --
-- covered by the GNU Public License. --
-- --
-- This unit was originally developed by Matthew J Heaney. --
------------------------------------------------------------------------------
with System; use type System.Address;
with Ada.Unchecked_Deallocation;
package body Ada.Containers.Indefinite_Doubly_Linked_Lists is
procedure Free is
new Ada.Unchecked_Deallocation (Element_Type, Element_Access);
-----------------------
-- Local Subprograms --
-----------------------
procedure Free (X : in out Node_Access);
procedure Insert_Internal
(Container : in out List;
Before : Node_Access;
New_Node : Node_Access);
function Vet (Position : Cursor) return Boolean;
---------
-- "=" --
---------
function "=" (Left, Right : List) return Boolean is
L : Node_Access;
R : Node_Access;
begin
if Left'Address = Right'Address then
return True;
end if;
if Left.Length /= Right.Length then
return False;
end if;
L := Left.First;
R := Right.First;
for J in 1 .. Left.Length loop
if L.Element.all /= R.Element.all then
return False;
end if;
L := L.Next;
R := R.Next;
end loop;
return True;
end "=";
------------
-- Adjust --
------------
procedure Adjust (Container : in out List) is
Src : Node_Access := Container.First;
Dst : Node_Access;
begin
if Src = null then
pragma Assert (Container.Last = null);
pragma Assert (Container.Length = 0);
pragma Assert (Container.Busy = 0);
pragma Assert (Container.Lock = 0);
return;
end if;
pragma Assert (Container.First.Prev = null);
pragma Assert (Container.Last.Next = null);
pragma Assert (Container.Length > 0);
Container.First := null;
Container.Last := null;
Container.Length := 0;
Container.Busy := 0;
Container.Lock := 0;
declare
Element : Element_Access := new Element_Type'(Src.Element.all);
begin
Dst := new Node_Type'(Element, null, null);
exception
when others =>
Free (Element);
raise;
end;
Container.First := Dst;
Container.Last := Dst;
Container.Length := 1;
Src := Src.Next;
while Src /= null loop
declare
Element : Element_Access := new Element_Type'(Src.Element.all);
begin
Dst := new Node_Type'(Element, null, Prev => Container.Last);
exception
when others =>
Free (Element);
raise;
end;
Container.Last.Next := Dst;
Container.Last := Dst;
Container.Length := Container.Length + 1;
Src := Src.Next;
end loop;
end Adjust;
------------
-- 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;
-----------
-- Clear --
-----------
procedure Clear (Container : in out List) is
X : Node_Access;
begin
if Container.Length = 0 then
pragma Assert (Container.First = null);
pragma Assert (Container.Last = null);
pragma Assert (Container.Busy = 0);
pragma Assert (Container.Lock = 0);
return;
end if;
pragma Assert (Container.First.Prev = null);
pragma Assert (Container.Last.Next = null);
if Container.Busy > 0 then
raise Program_Error;
end if;
while Container.Length > 1 loop
X := Container.First;
pragma Assert (X.Next.Prev = Container.First);
Container.First := X.Next;
Container.First.Prev := null;
Container.Length := Container.Length - 1;
Free (X);
end loop;
X := Container.First;
pragma Assert (X = Container.Last);
Container.First := null;
Container.Last := null;
Container.Length := 0;
Free (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
X : Node_Access;
begin
if Position.Node = null then
raise Constraint_Error;
end if;
if Position.Node.Element = null then
raise Program_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; -- Post-York behavior
return;
end if;
if Count = 0 then
Position := No_Element; -- Post-York behavior
return;
end if;
if Container.Busy > 0 then
raise Program_Error;
end if;
for Index in 1 .. Count loop
X := Position.Node;
Container.Length := Container.Length - 1;
if X = Container.Last then
Position := No_Element;
Container.Last := X.Prev;
Container.Last.Next := null;
Free (X);
return;
end if;
Position.Node := X.Next;
X.Next.Prev := X.Prev;
X.Prev.Next := X.Next;
Free (X);
end loop;
Position := No_Element; -- Post-York behavior
end Delete;
------------------
-- Delete_First --
------------------
procedure Delete_First
(Container : in out List;
Count : Count_Type := 1)
is
X : Node_Access;
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 (X.Next.Prev = Container.First);
Container.First := X.Next;
Container.First.Prev := null;
Container.Length := Container.Length - 1;
Free (X);
end loop;
end Delete_First;
-----------------
-- Delete_Last --
-----------------
procedure Delete_Last
(Container : in out List;
Count : Count_Type := 1)
is
X : Node_Access;
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 (X.Prev.Next = Container.Last);
Container.Last := X.Prev;
Container.Last.Next := null;
Container.Length := Container.Length - 1;
Free (X);
end loop;
end Delete_Last;
-------------
-- Element --
-------------
function Element (Position : Cursor) return Element_Type is
begin
if Position.Node = null then
raise Constraint_Error;
end if;
if Position.Node.Element = null then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Element");
return Position.Node.Element.all;
end Element;
----------
-- Find --
----------
function Find
(Container : List;
Item : Element_Type;
Position : Cursor := No_Element) return Cursor
is
Node : Node_Access := Position.Node;
begin
if Node = null then
Node := Container.First;
else
if Node.Element = null then
raise Program_Error;
end if;
if Position.Container /= Container'Unrestricted_Access then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Find");
end if;
while Node /= null loop
if Node.Element.all = Item then
return Cursor'(Container'Unchecked_Access, Node);
end if;
Node := Node.Next;
end loop;
return No_Element;
end Find;
-----------
-- First --
-----------
function First (Container : List) return Cursor is
begin
if Container.First = null then
return No_Element;
end if;
return Cursor'(Container'Unchecked_Access, Container.First);
end First;
-------------------
-- First_Element --
-------------------
function First_Element (Container : List) return Element_Type is
begin
if Container.First = null then
raise Constraint_Error;
end if;
return Container.First.Element.all;
end First_Element;
----------
-- Free --
----------
procedure Free (X : in out Node_Access) is
procedure Deallocate is
new Ada.Unchecked_Deallocation (Node_Type, Node_Access);
begin
X.Next := X;
X.Prev := X;
begin
Free (X.Element);
exception
when others =>
X.Element := null;
Deallocate (X);
raise;
end;
Deallocate (X);
end Free;
---------------------
-- Generic_Sorting --
---------------------
package body Generic_Sorting is
---------------
-- Is_Sorted --
---------------
function Is_Sorted (Container : List) return Boolean is
Node : Node_Access := Container.First;
begin
for I in 2 .. Container.Length loop
if Node.Next.Element.all < Node.Element.all then
return False;
end if;
Node := Node.Next;
end loop;
return True;
end Is_Sorted;
-----------
-- Merge --
-----------
procedure Merge
(Target : in out List;
Source : in out List)
is
LI : Cursor;
RI : Cursor;
begin
if Target'Address = Source'Address then
return;
end if;
if Target.Busy > 0
or else Source.Busy > 0
then
raise Program_Error;
end if;
LI := First (Target);
RI := First (Source);
while RI.Node /= null loop
pragma Assert (RI.Node.Next = null
or else not (RI.Node.Next.Element.all <
RI.Node.Element.all));
if LI.Node = null then
Splice (Target, No_Element, Source);
return;
end if;
pragma Assert (LI.Node.Next = null
or else not (LI.Node.Next.Element.all <
LI.Node.Element.all));
if RI.Node.Element.all < LI.Node.Element.all then
declare
RJ : Cursor := RI;
begin
RI.Node := RI.Node.Next;
Splice (Target, LI, Source, RJ);
end;
else
LI.Node := LI.Node.Next;
end if;
end loop;
end Merge;
----------
-- Sort --
----------
procedure Sort (Container : in out List) is
procedure Partition (Pivot : Node_Access; Back : Node_Access);
procedure Sort (Front, Back : Node_Access);
---------------
-- Partition --
---------------
procedure Partition (Pivot : Node_Access; Back : Node_Access) is
Node : Node_Access := Pivot.Next;
begin
while Node /= Back loop
if Node.Element.all < Pivot.Element.all then
declare
Prev : constant Node_Access := Node.Prev;
Next : constant Node_Access := Node.Next;
begin
Prev.Next := Next;
if Next = null then
Container.Last := Prev;
else
Next.Prev := Prev;
end if;
Node.Next := Pivot;
Node.Prev := Pivot.Prev;
Pivot.Prev := Node;
if Node.Prev = null then
Container.First := Node;
else
Node.Prev.Next := Node;
end if;
Node := Next;
end;
else
Node := Node.Next;
end if;
end loop;
end Partition;
----------
-- Sort --
----------
procedure Sort (Front, Back : Node_Access) is
Pivot : Node_Access;
begin
if Front = null then
Pivot := Container.First;
else
Pivot := Front.Next;
end if;
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 (Container.First.Prev = null);
pragma Assert (Container.Last.Next = null);
if Container.Busy > 0 then
raise Program_Error;
end if;
Sort (Front => null, Back => null);
pragma Assert (Container.First.Prev = null);
pragma Assert (Container.Last.Next = null);
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 /= null;
end Has_Element;
------------
-- Insert --
------------
procedure Insert
(Container : in out List;
Before : Cursor;
New_Item : Element_Type;
Position : out Cursor;
Count : Count_Type := 1)
is
New_Node : Node_Access;
begin
if Before.Container /= null then
if Before.Container /= Container'Unrestricted_Access then
raise Program_Error;
end if;
if Before.Node = null
or else Before.Node.Element = null
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 > Count_Type'Last - Count then
raise Constraint_Error;
end if;
if Container.Busy > 0 then
raise Program_Error;
end if;
declare
Element : Element_Access := new Element_Type'(New_Item);
begin
New_Node := new Node_Type'(Element, null, null);
exception
when others =>
Free (Element);
raise;
end;
Insert_Internal (Container, Before.Node, New_Node);
Position := Cursor'(Container'Unchecked_Access, New_Node);
for J in Count_Type'(2) .. Count loop
declare
Element : Element_Access := new Element_Type'(New_Item);
begin
New_Node := new Node_Type'(Element, null, null);
exception
when others =>
Free (Element);
raise;
end;
Insert_Internal (Container, Before.Node, New_Node);
end loop;
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;
---------------------
-- Insert_Internal --
---------------------
procedure Insert_Internal
(Container : in out List;
Before : Node_Access;
New_Node : Node_Access)
is
begin
if Container.Length = 0 then
pragma Assert (Before = null);
pragma Assert (Container.First = null);
pragma Assert (Container.Last = null);
Container.First := New_Node;
Container.Last := New_Node;
elsif Before = null then
pragma Assert (Container.Last.Next = null);
Container.Last.Next := New_Node;
New_Node.Prev := Container.Last;
Container.Last := New_Node;
elsif Before = Container.First then
pragma Assert (Container.First.Prev = null);
Container.First.Prev := New_Node;
New_Node.Next := Container.First;
Container.First := New_Node;
else
pragma Assert (Container.First.Prev = null);
pragma Assert (Container.Last.Next = null);
New_Node.Next := Before;
New_Node.Prev := Before.Prev;
Before.Prev.Next := New_Node;
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;
B : Natural renames C.Busy;
Node : Node_Access := Container.First;
begin
B := B + 1;
begin
while Node /= null loop
Process (Cursor'(Container'Unchecked_Access, Node));
Node := Node.Next;
end loop;
exception
when others =>
B := B - 1;
raise;
end;
B := B - 1;
end Iterate;
----------
-- Last --
----------
function Last (Container : List) return Cursor is
begin
if Container.Last = null then
return No_Element;
end if;
return Cursor'(Container'Unchecked_Access, Container.Last);
end Last;
------------------
-- Last_Element --
------------------
function Last_Element (Container : List) return Element_Type is
begin
if Container.Last = null then
raise Constraint_Error;
end if;
return Container.Last.Element.all;
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
begin
if Target'Address = Source'Address then
return;
end if;
if Source.Busy > 0 then
raise Program_Error;
end if;
Clear (Target);
Target.First := Source.First;
Source.First := null;
Target.Last := Source.Last;
Source.Last := null;
Target.Length := Source.Length;
Source.Length := 0;
end Move;
----------
-- Next --
----------
procedure Next (Position : in out Cursor) is
begin
pragma Assert (Vet (Position), "bad cursor in procedure Next");
if Position.Node = null then
return;
end if;
Position.Node := Position.Node.Next;
if Position.Node = null then
Position.Container := null;
end if;
end Next;
function Next (Position : Cursor) return Cursor is
begin
pragma Assert (Vet (Position), "bad cursor in function Next");
if Position.Node = null then
return No_Element;
end if;
declare
Next_Node : constant Node_Access := Position.Node.Next;
begin
if Next_Node = null then
return No_Element;
end if;
return Cursor'(Position.Container, Next_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
pragma Assert (Vet (Position), "bad cursor in procedure Previous");
if Position.Node = null then
return;
end if;
Position.Node := Position.Node.Prev;
if Position.Node = null then
Position.Container := null;
end if;
end Previous;
function Previous (Position : Cursor) return Cursor is
begin
pragma Assert (Vet (Position), "bad cursor in function Previous");
if Position.Node = null then
return No_Element;
end if;
declare
Prev_Node : constant Node_Access := Position.Node.Prev;
begin
if Prev_Node = null then
return No_Element;
end if;
return Cursor'(Position.Container, Prev_Node);
end;
end Previous;
-------------------
-- Query_Element --
-------------------
procedure Query_Element
(Position : Cursor;
Process : not null access procedure (Element : Element_Type))
is
begin
if Position.Node = null then
raise Constraint_Error;
end if;
if Position.Node.Element = null then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Query_Element");
declare
C : List renames Position.Container.all'Unrestricted_Access.all;
B : Natural renames C.Busy;
L : Natural renames C.Lock;
begin
B := B + 1;
L := L + 1;
begin
Process (Position.Node.Element.all);
exception
when others =>
L := L - 1;
B := B - 1;
raise;
end;
L := L - 1;
B := B - 1;
end;
end Query_Element;
----------
-- Read --
----------
procedure Read
(Stream : access Root_Stream_Type'Class;
Item : out List)
is
N : Count_Type'Base;
Dst : Node_Access;
begin
Clear (Item);
Count_Type'Base'Read (Stream, N);
if N = 0 then
return;
end if;
declare
Element : Element_Access :=
new Element_Type'(Element_Type'Input (Stream));
begin
Dst := new Node_Type'(Element, null, null);
exception
when others =>
Free (Element);
raise;
end;
Item.First := Dst;
Item.Last := Dst;
Item.Length := 1;
while Item.Length < N loop
declare
Element : Element_Access :=
new Element_Type'(Element_Type'Input (Stream));
begin
Dst := new Node_Type'(Element, Next => null, Prev => Item.Last);
exception
when others =>
Free (Element);
raise;
end;
Item.Last.Next := Dst;
Item.Last := Dst;
Item.Length := Item.Length + 1;
end loop;
end Read;
procedure Read
(Stream : access Root_Stream_Type'Class;
Item : out Cursor)
is
begin
raise Program_Error;
end Read;
---------------------
-- 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'Unchecked_Access then
raise Program_Error;
end if;
if Position.Container.Lock > 0 then
raise Program_Error;
end if;
if Position.Node.Element = null then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Replace_Element");
declare
X : Element_Access := Position.Node.Element;
begin
Position.Node.Element := new Element_Type'(New_Item);
Free (X);
end;
end Replace_Element;
----------------------
-- Reverse_Elements --
----------------------
procedure Reverse_Elements (Container : in out List) is
I : Node_Access := Container.First;
J : Node_Access := Container.Last;
procedure Swap (L, R : Node_Access);
----------
-- Swap --
----------
procedure Swap (L, R : Node_Access) is
LN : constant Node_Access := L.Next;
LP : constant Node_Access := L.Prev;
RN : constant Node_Access := R.Next;
RP : constant Node_Access := R.Prev;
begin
if LP /= null then
LP.Next := R;
end if;
if RN /= null then
RN.Prev := L;
end if;
L.Next := RN;
R.Prev := LP;
if LN = R then
pragma Assert (RP = L);
L.Prev := R;
R.Next := L;
else
L.Prev := RP;
RP.Next := L;
R.Next := LN;
LN.Prev := R;
end if;
end Swap;
-- Start of processing for Reverse_Elements
begin
if Container.Length <= 1 then
return;
end if;
pragma Assert (Container.First.Prev = null);
pragma Assert (Container.Last.Next = null);
if Container.Busy > 0 then
raise Program_Error;
end if;
Container.First := J;
Container.Last := I;
loop
Swap (L => I, R => J);
J := J.Next;
exit when I = J;
I := I.Prev;
exit when I = J;
Swap (L => J, R => I);
I := I.Next;
exit when I = J;
J := J.Prev;
exit when I = J;
end loop;
pragma Assert (Container.First.Prev = null);
pragma Assert (Container.Last.Next = null);
end Reverse_Elements;
------------------
-- Reverse_Find --
------------------
function Reverse_Find
(Container : List;
Item : Element_Type;
Position : Cursor := No_Element) return Cursor
is
Node : Node_Access := Position.Node;
begin
if Node = null then
Node := Container.Last;
else
if Node.Element = null then
raise Program_Error;
end if;
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 /= null loop
if Node.Element.all = Item then
return Cursor'(Container'Unchecked_Access, Node);
end if;
Node := 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;
B : Natural renames C.Busy;
Node : Node_Access := Container.Last;
begin
B := B + 1;
begin
while Node /= null loop
Process (Cursor'(Container'Unchecked_Access, Node));
Node := Node.Prev;
end loop;
exception
when others =>
B := B - 1;
raise;
end;
B := B - 1;
end Reverse_Iterate;
------------
-- Splice --
------------
procedure Splice
(Target : in out List;
Before : Cursor;
Source : in out List)
is
begin
if Before.Container /= null then
if Before.Container /= Target'Unrestricted_Access then
raise Program_Error;
end if;
if Before.Node = null
or else Before.Node.Element = null
then
raise Program_Error;
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;
pragma Assert (Source.First.Prev = null);
pragma Assert (Source.Last.Next = null);
if Target.Length > Count_Type'Last - Source.Length then
raise Constraint_Error;
end if;
if Target.Busy > 0
or else Source.Busy > 0
then
raise Program_Error;
end if;
if Target.Length = 0 then
pragma Assert (Before = No_Element);
pragma Assert (Target.First = null);
pragma Assert (Target.Last = null);
Target.First := Source.First;
Target.Last := Source.Last;
elsif Before.Node = null then
pragma Assert (Target.Last.Next = null);
Target.Last.Next := Source.First;
Source.First.Prev := Target.Last;
Target.Last := Source.Last;
elsif Before.Node = Target.First then
pragma Assert (Target.First.Prev = null);
Source.Last.Next := Target.First;
Target.First.Prev := Source.Last;
Target.First := Source.First;
else
pragma Assert (Target.Length >= 2);
Before.Node.Prev.Next := Source.First;
Source.First.Prev := Before.Node.Prev;
Before.Node.Prev := Source.Last;
Source.Last.Next := Before.Node;
end if;
Source.First := null;
Source.Last := null;
Target.Length := Target.Length + Source.Length;
Source.Length := 0;
end Splice;
procedure Splice
(Container : in out List;
Before : Cursor;
Position : in out Cursor)
is
begin
if Before.Container /= null then
if Before.Container /= Container'Unchecked_Access then
raise Program_Error;
end if;
if Before.Node = null
or else Before.Node.Element = null
then
raise Program_Error;
end if;
pragma Assert (Vet (Before), "bad Before cursor in Splice");
end if;
if Position.Node = null then
raise Constraint_Error;
end if;
if Position.Node.Element = null then
raise Program_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 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 = null then
pragma Assert (Position.Node /= Container.Last);
if Position.Node = Container.First then
Container.First := Position.Node.Next;
Container.First.Prev := null;
else
Position.Node.Prev.Next := Position.Node.Next;
Position.Node.Next.Prev := Position.Node.Prev;
end if;
Container.Last.Next := Position.Node;
Position.Node.Prev := Container.Last;
Container.Last := Position.Node;
Container.Last.Next := null;
return;
end if;
if Before.Node = Container.First then
pragma Assert (Position.Node /= Container.First);
if Position.Node = Container.Last then
Container.Last := Position.Node.Prev;
Container.Last.Next := null;
else
Position.Node.Prev.Next := Position.Node.Next;
Position.Node.Next.Prev := Position.Node.Prev;
end if;
Container.First.Prev := Position.Node;
Position.Node.Next := Container.First;
Container.First := Position.Node;
Container.First.Prev := null;
return;
end if;
if Position.Node = Container.First then
Container.First := Position.Node.Next;
Container.First.Prev := null;
elsif Position.Node = Container.Last then
Container.Last := Position.Node.Prev;
Container.Last.Next := null;
else
Position.Node.Prev.Next := Position.Node.Next;
Position.Node.Next.Prev := Position.Node.Prev;
end if;
Before.Node.Prev.Next := Position.Node;
Position.Node.Prev := Before.Node.Prev;
Before.Node.Prev := Position.Node;
Position.Node.Next := Before.Node;
pragma Assert (Container.First.Prev = null);
pragma Assert (Container.Last.Next = null);
end Splice;
procedure Splice
(Target : in out List;
Before : Cursor;
Source : in out List;
Position : in out Cursor)
is
begin
if Target'Address = Source'Address then
Splice (Target, Before, Position);
return;
end if;
if Before.Container /= null then
if Before.Container /= Target'Unrestricted_Access then
raise Program_Error;
end if;
if Before.Node = null
or else Before.Node.Element = null
then
raise Program_Error;
end if;
pragma Assert (Vet (Before), "bad Before cursor in Splice");
end if;
if Position.Node = null then
raise Constraint_Error;
end if;
if Position.Node.Element = null then
raise Program_Error;
end if;
if Position.Container /= Source'Unrestricted_Access then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad Position cursor in Splice");
if Target.Length = Count_Type'Last then
raise Constraint_Error;
end if;
if Target.Busy > 0
or else Source.Busy > 0
then
raise Program_Error;
end if;
if Position.Node = Source.First then
Source.First := Position.Node.Next;
if Position.Node = Source.Last then
pragma Assert (Source.First = null);
pragma Assert (Source.Length = 1);
Source.Last := null;
else
Source.First.Prev := null;
end if;
elsif Position.Node = Source.Last then
pragma Assert (Source.Length >= 2);
Source.Last := Position.Node.Prev;
Source.Last.Next := null;
else
pragma Assert (Source.Length >= 3);
Position.Node.Prev.Next := Position.Node.Next;
Position.Node.Next.Prev := Position.Node.Prev;
end if;
if Target.Length = 0 then
pragma Assert (Before = No_Element);
pragma Assert (Target.First = null);
pragma Assert (Target.Last = null);
Target.First := Position.Node;
Target.Last := Position.Node;
Target.First.Prev := null;
Target.Last.Next := null;
elsif Before.Node = null then
pragma Assert (Target.Last.Next = null);
Target.Last.Next := Position.Node;
Position.Node.Prev := Target.Last;
Target.Last := Position.Node;
Target.Last.Next := null;
elsif Before.Node = Target.First then
pragma Assert (Target.First.Prev = null);
Target.First.Prev := Position.Node;
Position.Node.Next := Target.First;
Target.First := Position.Node;
Target.First.Prev := null;
else
pragma Assert (Target.Length >= 2);
Before.Node.Prev.Next := Position.Node;
Position.Node.Prev := Before.Node.Prev;
Before.Node.Prev := Position.Node;
Position.Node.Next := Before.Node;
end if;
Target.Length := Target.Length + 1;
Source.Length := Source.Length - 1;
Position.Container := Target'Unchecked_Access;
end Splice;
----------
-- Swap --
----------
procedure Swap
(Container : in out List;
I, J : Cursor)
is
begin
if I.Node = null
or else J.Node = null
then
raise Constraint_Error;
end if;
if I.Container /= Container'Unchecked_Access
or else J.Container /= Container'Unchecked_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
EI_Copy : constant Element_Access := I.Node.Element;
begin
I.Node.Element := J.Node.Element;
J.Node.Element := EI_Copy;
end;
end Swap;
----------------
-- Swap_Links --
----------------
procedure Swap_Links
(Container : in out List;
I, J : Cursor)
is
begin
if I.Node = null
or else J.Node = null
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;
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;
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;
pragma Assert (Container.First.Prev = null);
pragma Assert (Container.Last.Next = null);
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 = null then
raise Constraint_Error;
end if;
if Position.Node.Element = null then
raise Program_Error;
end if;
if Position.Container /= Container'Unchecked_Access then
raise Program_Error;
end if;
pragma Assert (Vet (Position), "bad cursor in Update_Element");
declare
B : Natural renames Container.Busy;
L : Natural renames Container.Lock;
begin
B := B + 1;
L := L + 1;
begin
Process (Position.Node.Element.all);
exception
when others =>
L := L - 1;
B := B - 1;
raise;
end;
L := L - 1;
B := B - 1;
end;
end Update_Element;
---------
-- Vet --
---------
function Vet (Position : Cursor) return Boolean is
begin
if Position.Node = null then
return Position.Container = null;
end if;
if Position.Container = null then
return False;
end if;
if Position.Node.Next = Position.Node then
return False;
end if;
if Position.Node.Prev = Position.Node then
return False;
end if;
if Position.Node.Element = null then
return False;
end if;
declare
L : List renames Position.Container.all;
begin
if L.Length = 0 then
return False;
end if;
if L.First = null then
return False;
end if;
if L.Last = null then
return False;
end if;
if L.First.Prev /= null then
return False;
end if;
if L.Last.Next /= null then
return False;
end if;
if Position.Node.Prev = null
and then Position.Node /= L.First
then
return False;
end if;
if Position.Node.Next = null
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 L.First.Next = null then
return False;
end if;
if L.Last.Prev = null then
return False;
end if;
if L.First.Next.Prev /= L.First then
return False;
end if;
if L.Last.Prev.Next /= L.Last then
return False;
end if;
if L.Length = 2 then
if L.First.Next /= L.Last then
return False;
end if;
if L.Last.Prev /= L.First then
return False;
end if;
return True;
end if;
if L.First.Next = L.Last then
return False;
end if;
if 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 Position.Node.Next = null then
return False;
end if;
if Position.Node.Prev = null then
return False;
end if;
if Position.Node.Next.Prev /= Position.Node then
return False;
end if;
if Position.Node.Prev.Next /= Position.Node then
return False;
end if;
if L.Length = 3 then
if L.First.Next /= Position.Node then
return False;
end if;
if L.Last.Prev /= Position.Node then
return False;
end if;
end if;
return True;
end;
end Vet;
-----------
-- Write --
-----------
procedure Write
(Stream : access Root_Stream_Type'Class;
Item : List)
is
Node : Node_Access := Item.First;
begin
Count_Type'Base'Write (Stream, Item.Length);
while Node /= null loop
Element_Type'Output (Stream, Node.Element.all); -- X.all
Node := Node.Next;
end loop;
end Write;
procedure Write
(Stream : access Root_Stream_Type'Class;
Item : Cursor)
is
begin
raise Program_Error;
end Write;
end Ada.Containers.Indefinite_Doubly_Linked_Lists;