------------------------------------------------------------------------------ -- -- -- GNAT LIBRARY COMPONENTS -- -- -- -- ADA.CONTAINERS.FORMAL_INDEFINITE_DOUBLY_LINKED_LISTS -- -- -- -- B o d y -- -- -- -- Copyright (C) 2022-2022, 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 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 -- -- . -- ------------------------------------------------------------------------------ with Ada.Unchecked_Deallocation; with Ada.Containers.Stable_Sorting; use Ada.Containers.Stable_Sorting; with System; use type System.Address; with Ada.Numerics.Big_Numbers.Big_Integers; use Ada.Numerics.Big_Numbers.Big_Integers; package body Ada.Containers.Formal_Indefinite_Doubly_Linked_Lists with SPARK_Mode => Off is -- Convert Count_Type to Big_Integer package Conversions is new Signed_Conversions (Int => Count_Type); use Conversions; ----------------------- -- Local Subprograms -- ----------------------- procedure Allocate (Container : in out List; New_Item : Element_Type; New_Node : out Count_Type); procedure Allocate (Container : in out List; New_Node : out Count_Type); procedure Free (Container : in out List; X : Count_Type); procedure Insert_Internal (Container : in out List; Before : Count_Type; New_Node : Count_Type); function Vet (L : List; Position : Cursor) return Boolean with Inline; procedure Resize (Container : in out List) with -- Add more room in the internal array Global => null, Pre => Container.Nodes = null or else Length (Container) = Container.Nodes'Length, Post => Model (Container) = Model (Container)'Old and Positions (Container) = Positions (Container)'Old; procedure Finalize_Element is new Ada.Unchecked_Deallocation (Object => Element_Type, Name => Element_Access); procedure Finalize_Nodes is new Ada.Unchecked_Deallocation (Object => Node_Array, Name => Node_Array_Access); --------- -- "=" -- --------- function "=" (Left : List; Right : List) return Boolean is LI : Count_Type; RI : Count_Type; begin if Left'Address = Right'Address then return True; end if; if Left.Length /= Right.Length then return False; end if; LI := Left.First; RI := Right.First; while LI /= 0 loop if Left.Nodes (LI).Element.all /= Right.Nodes (RI).Element.all then return False; end if; LI := Left.Nodes (LI).Next; RI := Right.Nodes (RI).Next; end loop; return True; end "="; ------------ -- Adjust -- ------------ overriding procedure Adjust (Container : in out List) is N_Src : Node_Array_Access renames Container.Nodes; N_Tar : Node_Array_Access; begin if N_Src = null then return; end if; if Container.Length = 0 then Container.Nodes := null; Container.Free := -1; return; end if; N_Tar := new Node_Array (1 .. N_Src'Length); for X in 1 .. Count_Type (N_Src'Length) loop N_Tar (X) := N_Src (X); if N_Src (X).Element /= null then N_Tar (X).Element := new Element_Type'(N_Src (X).Element.all); end if; end loop; N_Src := N_Tar; end Adjust; -------------- -- Allocate -- -------------- procedure Allocate (Container : in out List; New_Node : out Count_Type) is N : Node_Array_Access renames Container.Nodes; begin if Container.Nodes = null or else Length (Container) = Container.Nodes'Length then Resize (Container); end if; if Container.Free >= 0 then New_Node := Container.Free; Container.Free := N (New_Node).Next; else New_Node := abs Container.Free; Container.Free := Container.Free - 1; end if; N (New_Node).Element := null; end Allocate; procedure Allocate (Container : in out List; New_Item : Element_Type; New_Node : out Count_Type) is N : Node_Array_Access renames Container.Nodes; begin Allocate (Container, New_Node); N (New_Node).Element := new Element_Type'(New_Item); end Allocate; ------------ -- Append -- ------------ procedure Append (Container : in out List; New_Item : Element_Type) is begin Insert (Container, No_Element, New_Item, 1); end Append; procedure Append (Container : in out List; New_Item : Element_Type; Count : Count_Type) is begin Insert (Container, No_Element, New_Item, Count); end Append; ------------ -- Assign -- ------------ procedure Assign (Target : in out List; Source : List) is N : Node_Array_Access renames Source.Nodes; J : Count_Type; begin if Target'Address = Source'Address then return; end if; Clear (Target); J := Source.First; while J /= 0 loop Append (Target, N (J).Element.all); J := N (J).Next; end loop; end Assign; ----------- -- Clear -- ----------- procedure Clear (Container : in out List) is N : Node_Array_Access renames Container.Nodes; X : Count_Type; begin if Container.Length = 0 then pragma Assert (Container.First = 0); pragma Assert (Container.Last = 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); 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; ------------------------ -- Constant_Reference -- ------------------------ function Constant_Reference (Container : List; Position : Cursor) return not null access constant Element_Type is begin if not Has_Element (Container => Container, Position => Position) then raise Constraint_Error with "Position cursor has no element"; end if; return Container.Nodes (Position.Node).Element; end Constant_Reference; -------------- -- Contains -- -------------- function Contains (Container : List; Item : Element_Type) return Boolean is begin return Find (Container, Item) /= No_Element; end Contains; ---------- -- Copy -- ---------- function Copy (Source : List) return List is N : Count_Type; P : List; begin if Source.Nodes = null then return P; end if; P.Nodes := new Node_Array (1 .. Source.Nodes'Length); N := 1; while N <= Source.Nodes'Length loop P.Nodes (N).Prev := Source.Nodes (N).Prev; P.Nodes (N).Next := Source.Nodes (N).Next; if Source.Nodes (N).Element /= null then P.Nodes (N).Element := new Element_Type'(Source.Nodes (N).Element.all); end if; N := N + 1; end loop; P.Free := Source.Free; P.Length := Source.Length; P.First := Source.First; P.Last := Source.Last; return P; end Copy; ------------ -- Delete -- ------------ procedure Delete (Container : in out List; Position : in out Cursor) is begin Delete (Container => Container, Position => Position, Count => 1); end Delete; procedure Delete (Container : in out List; Position : in out Cursor; Count : Count_Type) is N : Node_Array_Access renames Container.Nodes; X : Count_Type; begin if not Has_Element (Container => Container, Position => Position) then raise Constraint_Error with "Position cursor has no element"; end if; pragma Assert (Vet (Container, Position), "bad cursor in Delete"); 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 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; 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; pragma Assert (N (Position.Node).Prev >= 0); 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) is begin Delete_First (Container => Container, Count => 1); end Delete_First; procedure Delete_First (Container : in out List; Count : Count_Type) is N : Node_Array_Access renames Container.Nodes; X : Count_Type; begin if Count >= Container.Length then Clear (Container); return; end if; if Count = 0 then return; end if; for J 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) is begin Delete_Last (Container => Container, Count => 1); end Delete_Last; procedure Delete_Last (Container : in out List; Count : Count_Type) is N : Node_Array_Access renames Container.Nodes; X : Count_Type; begin if Count >= Container.Length then Clear (Container); return; end if; if Count = 0 then return; end if; for J 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 (Container : List; Position : Cursor) return Element_Type is begin if not Has_Element (Container => Container, Position => Position) then raise Constraint_Error with "Position cursor has no element"; end if; return Container.Nodes (Position.Node).Element.all; end Element; ---------------- -- Empty_List -- ---------------- function Empty_List return List is ((Controlled with others => <>)); -------------- -- Finalize -- -------------- procedure Finalize (Container : in out List) is X : Count_Type := Container.First; N : Node_Array_Access renames Container.Nodes; begin if N = null then return; end if; while X /= 0 loop Finalize_Element (N (X).Element); X := N (X).Next; end loop; Finalize_Nodes (N); Container.Free := 0; Container.Last := 0; Container.First := 0; Container.Length := 0; end Finalize; ---------- -- Find -- ---------- function Find (Container : List; Item : Element_Type; Position : Cursor := No_Element) return Cursor is From : Count_Type := Position.Node; begin if From = 0 and Container.Length = 0 then return No_Element; end if; if From = 0 then From := Container.First; end if; if Position.Node /= 0 and then not Has_Element (Container, Position) then raise Constraint_Error with "Position cursor has no element"; end if; while From /= 0 loop if Container.Nodes (From).Element.all = Item then return (Node => From); end if; From := Container.Nodes (From).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 (Node => Container.First); end First; ------------------- -- First_Element -- ------------------- function First_Element (Container : List) return Element_Type is F : constant Count_Type := Container.First; begin if F = 0 then raise Constraint_Error with "list is empty"; else return Container.Nodes (F).Element.all; end if; end First_Element; ------------------ -- Formal_Model -- ------------------ package body Formal_Model is ---------------------------- -- Lift_Abstraction_Level -- ---------------------------- procedure Lift_Abstraction_Level (Container : List) is null; ------------------------- -- M_Elements_In_Union -- ------------------------- function M_Elements_In_Union (Container : M.Sequence; Left : M.Sequence; Right : M.Sequence) return Boolean is Elem : Element_Type; begin for Index in 1 .. M.Length (Container) loop Elem := Element (Container, Index); if not M.Contains (Left, 1, M.Length (Left), Elem) and then not M.Contains (Right, 1, M.Length (Right), Elem) then return False; end if; end loop; return True; end M_Elements_In_Union; ------------------------- -- M_Elements_Included -- ------------------------- function M_Elements_Included (Left : M.Sequence; L_Fst : Positive_Count_Type := 1; L_Lst : Count_Type; Right : M.Sequence; R_Fst : Positive_Count_Type := 1; R_Lst : Count_Type) return Boolean is begin for I in L_Fst .. L_Lst loop declare Found : Boolean := False; J : Count_Type := R_Fst - 1; begin while not Found and J < R_Lst loop J := J + 1; if Element (Left, I) = Element (Right, J) then Found := True; end if; end loop; if not Found then return False; end if; end; end loop; return True; end M_Elements_Included; ------------------------- -- M_Elements_Reversed -- ------------------------- function M_Elements_Reversed (Left : M.Sequence; Right : M.Sequence) return Boolean is L : constant Count_Type := M.Length (Left); begin if L /= M.Length (Right) then return False; end if; for I in 1 .. L loop if Element (Left, I) /= Element (Right, L - I + 1) then return False; end if; end loop; return True; end M_Elements_Reversed; ------------------------ -- M_Elements_Swapped -- ------------------------ function M_Elements_Swapped (Left : M.Sequence; Right : M.Sequence; X : Positive_Count_Type; Y : Positive_Count_Type) return Boolean is begin if M.Length (Left) /= M.Length (Right) or else Element (Left, X) /= Element (Right, Y) or else Element (Left, Y) /= Element (Right, X) then return False; end if; for I in 1 .. M.Length (Left) loop if I /= X and then I /= Y and then Element (Left, I) /= Element (Right, I) then return False; end if; end loop; return True; end M_Elements_Swapped; ----------- -- Model -- ----------- function Model (Container : List) return M.Sequence is Position : Count_Type := Container.First; R : M.Sequence; begin -- Can't use First, Next or Element here, since they depend on models -- for their postconditions. while Position /= 0 loop R := M.Add (R, Container.Nodes (Position).Element.all); Position := Container.Nodes (Position).Next; end loop; return R; end Model; ----------------------- -- Mapping_Preserved -- ----------------------- function Mapping_Preserved (M_Left : M.Sequence; M_Right : M.Sequence; P_Left : P.Map; P_Right : P.Map) return Boolean is begin for C of P_Left loop if not P.Has_Key (P_Right, C) or else P.Get (P_Left, C) > M.Length (M_Left) or else P.Get (P_Right, C) > M.Length (M_Right) or else M.Get (M_Left, P.Get (P_Left, C)) /= M.Get (M_Right, P.Get (P_Right, C)) then return False; end if; end loop; for C of P_Right loop if not P.Has_Key (P_Left, C) then return False; end if; end loop; return True; end Mapping_Preserved; ------------------------- -- P_Positions_Shifted -- ------------------------- function P_Positions_Shifted (Small : P.Map; Big : P.Map; Cut : Positive_Count_Type; Count : Count_Type := 1) return Boolean is begin for Cu of Small loop if not P.Has_Key (Big, Cu) then return False; end if; end loop; for Cu of Big loop declare Pos : constant Positive_Count_Type := P.Get (Big, Cu); begin if Pos < Cut then if not P.Has_Key (Small, Cu) or else Pos /= P.Get (Small, Cu) then return False; end if; elsif Pos >= Cut + Count then if not P.Has_Key (Small, Cu) or else Pos /= P.Get (Small, Cu) + Count then return False; end if; else if P.Has_Key (Small, Cu) then return False; end if; end if; end; end loop; return True; end P_Positions_Shifted; ------------------------- -- P_Positions_Swapped -- ------------------------- function P_Positions_Swapped (Left : P.Map; Right : P.Map; X : Cursor; Y : Cursor) return Boolean is begin if not P.Has_Key (Left, X) or not P.Has_Key (Left, Y) or not P.Has_Key (Right, X) or not P.Has_Key (Right, Y) then return False; end if; if P.Get (Left, X) /= P.Get (Right, Y) or P.Get (Left, Y) /= P.Get (Right, X) then return False; end if; for C of Left loop if not P.Has_Key (Right, C) then return False; end if; end loop; for C of Right loop if not P.Has_Key (Left, C) or else (C /= X and C /= Y and P.Get (Left, C) /= P.Get (Right, C)) then return False; end if; end loop; return True; end P_Positions_Swapped; --------------------------- -- P_Positions_Truncated -- --------------------------- function P_Positions_Truncated (Small : P.Map; Big : P.Map; Cut : Positive_Count_Type; Count : Count_Type := 1) return Boolean is begin for Cu of Small loop if not P.Has_Key (Big, Cu) then return False; end if; end loop; for Cu of Big loop declare Pos : constant Positive_Count_Type := P.Get (Big, Cu); begin if Pos < Cut then if not P.Has_Key (Small, Cu) or else Pos /= P.Get (Small, Cu) then return False; end if; elsif Pos >= Cut + Count then return False; elsif P.Has_Key (Small, Cu) then return False; end if; end; end loop; return True; end P_Positions_Truncated; --------------- -- Positions -- --------------- function Positions (Container : List) return P.Map is I : Count_Type := 1; Position : Count_Type := Container.First; R : P.Map; begin -- Can't use First, Next or Element here, since they depend on models -- for their postconditions. while Position /= 0 loop R := P.Add (R, (Node => Position), I); pragma Assert (P.Length (R) = To_Big_Integer (I)); Position := Container.Nodes (Position).Next; I := I + 1; end loop; return R; end Positions; end Formal_Model; ---------- -- Free -- ---------- procedure Free (Container : in out List; X : Count_Type) is pragma Assert (X > 0); pragma Assert (X <= Container.Nodes'Length); N : Node_Array_Access renames Container.Nodes; begin N (X).Prev := -1; -- Node is deallocated (not on active list) if N (X).Element /= null then Finalize_Element (N (X).Element); end if; 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; for J in Container.Free .. Container.Nodes'Length loop N (J).Next := J + 1; end loop; N (Container.Nodes'Length).Next := 0; N (X).Next := Container.Free; Container.Free := X; end if; end Free; --------------------- -- Generic_Sorting -- --------------------- package body Generic_Sorting with SPARK_Mode => Off is ------------------ -- Formal_Model -- ------------------ package body Formal_Model is ----------------------- -- M_Elements_Sorted -- ----------------------- function M_Elements_Sorted (Container : M.Sequence) return Boolean is begin if M.Length (Container) = 0 then return True; end if; declare E1 : Element_Type := Element (Container, 1); begin for I in 2 .. M.Length (Container) loop declare E2 : constant Element_Type := Element (Container, I); begin if E2 < E1 then return False; end if; E1 := E2; end; end loop; end; return True; end M_Elements_Sorted; end Formal_Model; --------------- -- Is_Sorted -- --------------- function Is_Sorted (Container : List) return Boolean is Nodes : Node_Array_Access renames Container.Nodes; Node : Count_Type := Container.First; begin for J in 2 .. Container.Length loop if Nodes (Nodes (Node).Next).Element.all < Nodes (Node).Element.all then return False; else Node := Nodes (Node).Next; end if; end loop; return True; end Is_Sorted; ----------- -- Merge -- ----------- procedure Merge (Target : in out List; Source : in out List) is LN : Node_Array_Access renames Target.Nodes; RN : Node_Array_Access renames Source.Nodes; LI : Cursor; RI : Cursor; begin if Target'Address = Source'Address then raise Program_Error with "Target and Source denote same container"; end if; LI := First (Target); RI := First (Source); while RI.Node /= 0 loop pragma Assert (RN (RI.Node).Next = 0 or else not (RN (RN (RI.Node).Next).Element.all < RN (RI.Node).Element.all)); if LI.Node = 0 then Splice (Target, No_Element, Source); return; end if; pragma Assert (LN (LI.Node).Next = 0 or else not (LN (LN (LI.Node).Next).Element.all < LN (LI.Node).Element.all)); if RN (RI.Node).Element.all < LN (LI.Node).Element.all then declare RJ : Cursor := RI; pragma Warnings (Off, RJ); begin RI.Node := RN (RI.Node).Next; Splice (Target, LI, Source, RJ); end; else LI.Node := LN (LI.Node).Next; end if; end loop; end Merge; ---------- -- Sort -- ---------- procedure Sort (Container : in out List) is N : Node_Array_Access renames Container.Nodes; begin if Container.Length <= 1 then return; end if; pragma Assert (N (Container.First).Prev = 0); pragma Assert (N (Container.Last).Next = 0); 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.all < N (R).Element.all); 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 (Container : List; Position : Cursor) return Boolean is begin if Position.Node = 0 then return False; end if; return Container.Nodes (Position.Node).Prev /= -1; end Has_Element; ------------ -- Insert -- ------------ procedure Insert (Container : in out List; Before : Cursor; New_Item : Element_Type; Position : out Cursor; Count : Count_Type) is J : Count_Type; begin if Before.Node /= 0 then pragma Assert (Vet (Container, Before), "bad cursor in Insert"); end if; if Count = 0 then Position := Before; return; end if; Allocate (Container, New_Item, New_Node => J); Insert_Internal (Container, Before.Node, New_Node => J); Position := (Node => J); for Index in 2 .. Count loop Allocate (Container, New_Item, New_Node => J); Insert_Internal (Container, Before.Node, New_Node => J); end loop; end Insert; procedure Insert (Container : in out List; Before : Cursor; New_Item : Element_Type; Position : out Cursor) is begin Insert (Container => Container, Before => Before, New_Item => New_Item, Position => Position, Count => 1); end Insert; procedure Insert (Container : in out List; Before : Cursor; New_Item : Element_Type; Count : Count_Type) is Position : Cursor; begin Insert (Container, Before, New_Item, Position, Count); end Insert; procedure Insert (Container : in out List; Before : Cursor; New_Item : Element_Type) is Position : Cursor; begin Insert (Container, Before, New_Item, Position, 1); end Insert; --------------------- -- Insert_Internal -- --------------------- procedure Insert_Internal (Container : in out List; Before : Count_Type; New_Node : Count_Type) is N : Node_Array_Access 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 Length (Container) = 0; end Is_Empty; ---------- -- Last -- ---------- function Last (Container : List) return Cursor is begin if Container.Last = 0 then return No_Element; end if; return (Node => Container.Last); end Last; ------------------ -- Last_Element -- ------------------ function Last_Element (Container : List) return Element_Type is L : constant Count_Type := Container.Last; begin if L = 0 then raise Constraint_Error with "list is empty"; else return Container.Nodes (L).Element.all; end if; end Last_Element; ------------ -- Length -- ------------ function Length (Container : List) return Count_Type is begin return Container.Length; end Length; ---------- -- Move -- ---------- procedure Move (Target : in out List; Source : in out List) is N : Node_Array_Access renames Source.Nodes; procedure Finalize_Node_Array is new Ada.Unchecked_Deallocation (Object => Node_Array, Name => Node_Array_Access); begin if Target'Address = Source'Address then return; end if; Clear (Target); if Source.Length = 0 then return; end if; -- Make sure that Target is large enough if Target.Nodes = null or else Target.Nodes'Length < Source.Length then if Target.Nodes /= null then Finalize_Node_Array (Target.Nodes); end if; Target.Nodes := new Node_Array (1 .. Source.Length); end if; -- Copy first element from Source to Target Target.First := 1; Target.Nodes (1).Prev := 0; Target.Nodes (1).Element := N (Source.First).Element; N (Source.First).Element := null; -- Copy the other elements declare X_Src : Count_Type := N (Source.First).Next; X_Tar : Count_Type := 2; begin while X_Src /= 0 loop Target.Nodes (X_Tar).Prev := X_Tar - 1; Target.Nodes (X_Tar - 1).Next := X_Tar; Target.Nodes (X_Tar).Element := N (X_Src).Element; N (X_Src).Element := null; X_Src := N (X_Src).Next; X_Tar := X_Tar + 1; end loop; end; Target.Last := Source.Length; Target.Length := Source.Length; Target.Nodes (Target.Last).Next := 0; -- Set up the free list Target.Free := -Source.Length - 1; -- It is possible to Clear Source because the Element accesses were -- set to null. Clear (Source); end Move; ---------- -- Next -- ---------- procedure Next (Container : List; Position : in out Cursor) is begin Position := Next (Container, Position); end Next; function Next (Container : List; Position : Cursor) return Cursor is begin if Position.Node = 0 then return No_Element; end if; if not Has_Element (Container, Position) then raise Program_Error with "Position cursor has no element"; end if; return (Node => Container.Nodes (Position.Node).Next); end Next; ------------- -- Prepend -- ------------- procedure Prepend (Container : in out List; New_Item : Element_Type) is begin Insert (Container, First (Container), New_Item, 1); end Prepend; procedure Prepend (Container : in out List; New_Item : Element_Type; Count : Count_Type) is begin Insert (Container, First (Container), New_Item, Count); end Prepend; -------------- -- Previous -- -------------- procedure Previous (Container : List; Position : in out Cursor) is begin Position := Previous (Container, Position); end Previous; function Previous (Container : List; Position : Cursor) return Cursor is begin if Position.Node = 0 then return No_Element; end if; if not Has_Element (Container, Position) then raise Program_Error with "Position cursor has no element"; end if; return (Node => Container.Nodes (Position.Node).Prev); end Previous; --------------- -- Reference -- --------------- function Reference (Container : not null access List; Position : Cursor) return not null access Element_Type is begin if not Has_Element (Container.all, Position) then raise Constraint_Error with "Position cursor has no element"; end if; return Container.Nodes (Position.Node).Element; end Reference; --------------------- -- Replace_Element -- --------------------- procedure Replace_Element (Container : in out List; Position : Cursor; New_Item : Element_Type) is begin if not Has_Element (Container, Position) then raise Constraint_Error with "Position cursor has no element"; end if; pragma Assert (Vet (Container, Position), "bad cursor in Replace_Element"); Finalize_Element (Container.Nodes (Position.Node).Element); Container.Nodes (Position.Node).Element := new Element_Type'(New_Item); end Replace_Element; ------------ -- Resize -- ------------ procedure Resize (Container : in out List) is Min_Size : constant Count_Type := 100; begin if Container.Nodes = null then Container.Nodes := new Node_Array (1 .. Min_Size); Container.First := 0; Container.Last := 0; Container.Length := 0; Container.Free := -1; return; end if; if Container.Length /= Container.Nodes'Length then raise Program_Error with "List must be at size max to resize"; end if; declare procedure Finalize_Node_Array is new Ada.Unchecked_Deallocation (Object => Node_Array, Name => Node_Array_Access); New_Size : constant Count_Type := (if Container.Nodes'Length > Count_Type'Last / 2 then Count_Type'Last else 2 * Container.Nodes'Length); New_Nodes : Node_Array_Access; begin New_Nodes := new Node_Array (1 .. Count_Type'Max (New_Size, Min_Size)); New_Nodes (1 .. Container.Nodes'Length) := Container.Nodes (1 .. Container.Nodes'Length); Container.Free := -Container.Nodes'Length - 1; Finalize_Node_Array (Container.Nodes); Container.Nodes := New_Nodes; end; end Resize; ---------------------- -- Reverse_Elements -- ---------------------- procedure Reverse_Elements (Container : in out List) is N : Node_Array_Access renames Container.Nodes; I : Count_Type := Container.First; J : Count_Type := Container.Last; procedure Swap (L : Count_Type; R : Count_Type); ---------- -- Swap -- ---------- procedure Swap (L : Count_Type; 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); 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 CFirst : Count_Type := Position.Node; begin if CFirst = 0 then CFirst := Container.Last; end if; if Container.Length = 0 then return No_Element; else while CFirst /= 0 loop if Container.Nodes (CFirst).Element.all = Item then return (Node => CFirst); else CFirst := Container.Nodes (CFirst).Prev; end if; end loop; return No_Element; end if; end Reverse_Find; ------------ -- Splice -- ------------ procedure Splice (Target : in out List; Before : Cursor; Source : in out List) is SN : Node_Array_Access renames Source.Nodes; TN : Node_Array_Access renames Target.Nodes; begin if Target'Address = Source'Address then raise Program_Error with "Target and Source denote same container"; end if; if Before.Node /= 0 then pragma Assert (Vet (Target, Before), "bad cursor in Splice"); end if; if Is_Empty (Source) then return; end if; pragma Assert (SN (Source.First).Prev = 0); pragma Assert (SN (Source.Last).Next = 0); declare X : Count_Type; begin while not Is_Empty (Source) loop Allocate (Target, X); TN (X).Element := SN (Source.Last).Element; -- Insert the new node in Target Insert_Internal (Target, Before.Node, X); -- Free the last node of Source SN (Source.Last).Element := null; Delete_Last (Source); end loop; end; 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 raise Program_Error with "Target and Source denote same container"; end if; if Position.Node = 0 then raise Constraint_Error with "Position cursor has no element"; end if; pragma Assert (Vet (Source, Position), "bad Position cursor in Splice"); declare X : Count_Type; begin Allocate (Target, X); Target.Nodes (X).Element := Source.Nodes (Position.Node).Element; -- Insert the new node in Target Insert_Internal (Target, Before.Node, X); -- Free the node at position Position in Source Source.Nodes (Position.Node).Element := null; Delete (Source, Position); Position := (Node => X); end; end Splice; procedure Splice (Container : in out List; Before : Cursor; Position : Cursor) is N : Node_Array_Access renames Container.Nodes; begin if Before.Node /= 0 then pragma Assert (Vet (Container, Before), "bad Before cursor in Splice"); end if; if Position.Node = 0 then raise Constraint_Error with "Position cursor has no element"; end if; pragma Assert (Vet (Container, 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 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 : Cursor; J : Cursor) is begin if I.Node = 0 then raise Constraint_Error with "I cursor has no element"; end if; if J.Node = 0 then raise Constraint_Error with "J cursor has no element"; end if; if I.Node = J.Node then return; end if; pragma Assert (Vet (Container, I), "bad I cursor in Swap"); pragma Assert (Vet (Container, J), "bad J cursor in Swap"); declare NN : Node_Array_Access renames Container.Nodes; NI : Node_Type renames NN (I.Node); NJ : Node_Type renames NN (J.Node); EI_Copy : constant Element_Access := NI.Element; begin NI.Element := NJ.Element; NJ.Element := EI_Copy; end; end Swap; ---------------- -- Swap_Links -- ---------------- procedure Swap_Links (Container : in out List; I : Cursor; J : Cursor) is I_Next : Cursor; J_Next : Cursor; begin if I.Node = 0 then raise Constraint_Error with "I cursor has no element"; end if; if J.Node = 0 then raise Constraint_Error with "J cursor has no element"; end if; if I.Node = J.Node then return; end if; pragma Assert (Vet (Container, I), "bad I cursor in Swap_Links"); pragma Assert (Vet (Container, J), "bad J cursor in Swap_Links"); I_Next := Next (Container, I); if I_Next = J then Splice (Container, Before => I, Position => J); else J_Next := Next (Container, J); if J_Next = I then Splice (Container, Before => J, Position => I); else pragma Assert (Container.Length >= 3); Splice (Container, Before => I_Next, Position => J); Splice (Container, Before => J_Next, Position => I); end if; end if; end Swap_Links; --------- -- Vet -- --------- function Vet (L : List; Position : Cursor) return Boolean is N : Node_Array_Access renames L.Nodes; begin if not Container_Checks'Enabled then return True; end if; 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.Nodes'Length then return False; end if; if N (Position.Node).Prev < 0 or else N (Position.Node).Prev > L.Nodes'Length then return False; end if; if N (Position.Node).Next > L.Nodes'Length 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 Vet; end Ada.Containers.Formal_Indefinite_Doubly_Linked_Lists;