| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT LIBRARY COMPONENTS -- |
| -- -- |
| -- ADA.CONTAINERS.RESTRICTED_DOUBLY_LINKED_LISTS -- |
| -- -- |
| -- B o d y -- |
| -- -- |
| -- Copyright (C) 2004-2014, 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 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; |
| |
| --------- |
| -- "=" -- |
| --------- |
| |
| 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; |
| |
| procedure Partition (Pivot, Back : Count_Type); |
| procedure Sort (Front, Back : Count_Type); |
| |
| --------------- |
| -- Partition -- |
| --------------- |
| |
| procedure Partition (Pivot, Back : Count_Type) is |
| Node : Count_Type := N (Pivot).Next; |
| |
| begin |
| 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); |
| |
| -- if Container.Busy > 0 then |
| -- raise Program_Error; |
| -- end if; |
| |
| Sort (Front => 0, Back => 0); |
| |
| 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; |
| 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; -- 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 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; |
