------------------------------------------------------------------------------ -- -- -- GNAT LIBRARY COMPONENTS -- -- -- -- A D A . C O N T A I N E R S . B O U N D E D _ H A S H E D _ S E T S -- -- -- -- B o d y -- -- -- -- Copyright (C) 2004-2013, 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 -- -- . -- -- -- -- This unit was originally developed by Matthew J Heaney. -- ------------------------------------------------------------------------------ with Ada.Containers.Hash_Tables.Generic_Bounded_Operations; pragma Elaborate_All (Ada.Containers.Hash_Tables.Generic_Bounded_Operations); with Ada.Containers.Hash_Tables.Generic_Bounded_Keys; pragma Elaborate_All (Ada.Containers.Hash_Tables.Generic_Bounded_Keys); with Ada.Containers.Prime_Numbers; use Ada.Containers.Prime_Numbers; with System; use type System.Address; package body Ada.Containers.Bounded_Hashed_Sets is ----------------------- -- Local Subprograms -- ----------------------- function Equivalent_Keys (Key : Element_Type; Node : Node_Type) return Boolean; pragma Inline (Equivalent_Keys); function Hash_Node (Node : Node_Type) return Hash_Type; pragma Inline (Hash_Node); procedure Insert (Container : in out Set; New_Item : Element_Type; Node : out Count_Type; Inserted : out Boolean); function Is_In (HT : Set; Key : Node_Type) return Boolean; pragma Inline (Is_In); procedure Set_Element (Node : in out Node_Type; Item : Element_Type); pragma Inline (Set_Element); function Next (Node : Node_Type) return Count_Type; pragma Inline (Next); procedure Set_Next (Node : in out Node_Type; Next : Count_Type); pragma Inline (Set_Next); function Vet (Position : Cursor) return Boolean; -------------------------- -- Local Instantiations -- -------------------------- package HT_Ops is new Hash_Tables.Generic_Bounded_Operations (HT_Types => HT_Types, Hash_Node => Hash_Node, Next => Next, Set_Next => Set_Next); package Element_Keys is new Hash_Tables.Generic_Bounded_Keys (HT_Types => HT_Types, Next => Next, Set_Next => Set_Next, Key_Type => Element_Type, Hash => Hash, Equivalent_Keys => Equivalent_Keys); procedure Replace_Element is new Element_Keys.Generic_Replace_Element (Hash_Node, Set_Element); --------- -- "=" -- --------- function "=" (Left, Right : Set) return Boolean is function Find_Equal_Key (R_HT : Hash_Table_Type'Class; L_Node : Node_Type) return Boolean; pragma Inline (Find_Equal_Key); function Is_Equal is new HT_Ops.Generic_Equal (Find_Equal_Key); -------------------- -- Find_Equal_Key -- -------------------- function Find_Equal_Key (R_HT : Hash_Table_Type'Class; L_Node : Node_Type) return Boolean is R_Index : constant Hash_Type := Element_Keys.Index (R_HT, L_Node.Element); R_Node : Count_Type := R_HT.Buckets (R_Index); begin loop if R_Node = 0 then return False; end if; if L_Node.Element = R_HT.Nodes (R_Node).Element then return True; end if; R_Node := Next (R_HT.Nodes (R_Node)); end loop; end Find_Equal_Key; -- Start of processing for "=" begin return Is_Equal (Left, Right); end "="; ------------ -- Assign -- ------------ procedure Assign (Target : in out Set; Source : Set) is procedure Insert_Element (Source_Node : Count_Type); procedure Insert_Elements is new HT_Ops.Generic_Iteration (Insert_Element); -------------------- -- Insert_Element -- -------------------- procedure Insert_Element (Source_Node : Count_Type) is N : Node_Type renames Source.Nodes (Source_Node); X : Count_Type; B : Boolean; begin Insert (Target, N.Element, X, B); pragma Assert (B); end Insert_Element; -- Start of processing for Assign begin if Target'Address = Source'Address then return; end if; if Target.Capacity < Source.Length then raise Capacity_Error with "Target capacity is less than Source length"; end if; HT_Ops.Clear (Target); Insert_Elements (Source); end Assign; -------------- -- Capacity -- -------------- function Capacity (Container : Set) return Count_Type is begin return Container.Capacity; end Capacity; ----------- -- Clear -- ----------- procedure Clear (Container : in out Set) is begin HT_Ops.Clear (Container); end Clear; ------------------------ -- Constant_Reference -- ------------------------ function Constant_Reference (Container : aliased Set; Position : Cursor) return Constant_Reference_Type is begin if Position.Container = null then raise Constraint_Error with "Position cursor has no element"; end if; if Position.Container /= Container'Unrestricted_Access then raise Program_Error with "Position cursor designates wrong container"; end if; pragma Assert (Vet (Position), "bad cursor in Constant_Reference"); declare N : Node_Type renames Container.Nodes (Position.Node); begin return (Element => N.Element'Access); end; end Constant_Reference; -------------- -- Contains -- -------------- function Contains (Container : Set; Item : Element_Type) return Boolean is begin return Find (Container, Item) /= No_Element; end Contains; ---------- -- Copy -- ---------- function Copy (Source : Set; Capacity : Count_Type := 0; Modulus : Hash_Type := 0) return Set is C : Count_Type; M : Hash_Type; begin if Capacity = 0 then C := Source.Length; elsif Capacity >= Source.Length then C := Capacity; else raise Capacity_Error with "Capacity value too small"; end if; if Modulus = 0 then M := Default_Modulus (C); else M := Modulus; end if; return Target : Set (Capacity => C, Modulus => M) do Assign (Target => Target, Source => Source); end return; end Copy; --------------------- -- Default_Modulus -- --------------------- function Default_Modulus (Capacity : Count_Type) return Hash_Type is begin return To_Prime (Capacity); end Default_Modulus; ------------ -- Delete -- ------------ procedure Delete (Container : in out Set; Item : Element_Type) is X : Count_Type; begin Element_Keys.Delete_Key_Sans_Free (Container, Item, X); if X = 0 then raise Constraint_Error with "attempt to delete element not in set"; end if; HT_Ops.Free (Container, X); end Delete; procedure Delete (Container : in out Set; Position : in out Cursor) is begin if Position.Node = 0 then raise Constraint_Error with "Position cursor equals No_Element"; end if; if Position.Container /= Container'Unrestricted_Access then raise Program_Error with "Position cursor designates wrong set"; end if; if Container.Busy > 0 then raise Program_Error with "attempt to tamper with cursors (set is busy)"; end if; pragma Assert (Vet (Position), "bad cursor in Delete"); HT_Ops.Delete_Node_Sans_Free (Container, Position.Node); HT_Ops.Free (Container, Position.Node); Position := No_Element; end Delete; ---------------- -- Difference -- ---------------- procedure Difference (Target : in out Set; Source : Set) is Tgt_Node, Src_Node : Count_Type; Src : Set renames Source'Unrestricted_Access.all; TN : Nodes_Type renames Target.Nodes; SN : Nodes_Type renames Source.Nodes; begin if Target'Address = Source'Address then HT_Ops.Clear (Target); return; end if; if Source.Length = 0 then return; end if; if Target.Busy > 0 then raise Program_Error with "attempt to tamper with cursors (set is busy)"; end if; if Source.Length < Target.Length then Src_Node := HT_Ops.First (Source); while Src_Node /= 0 loop Tgt_Node := Element_Keys.Find (Target, SN (Src_Node).Element); if Tgt_Node /= 0 then HT_Ops.Delete_Node_Sans_Free (Target, Tgt_Node); HT_Ops.Free (Target, Tgt_Node); end if; Src_Node := HT_Ops.Next (Src, Src_Node); end loop; else Tgt_Node := HT_Ops.First (Target); while Tgt_Node /= 0 loop if Is_In (Source, TN (Tgt_Node)) then declare X : constant Count_Type := Tgt_Node; begin Tgt_Node := HT_Ops.Next (Target, Tgt_Node); HT_Ops.Delete_Node_Sans_Free (Target, X); HT_Ops.Free (Target, X); end; else Tgt_Node := HT_Ops.Next (Target, Tgt_Node); end if; end loop; end if; end Difference; function Difference (Left, Right : Set) return Set is begin if Left'Address = Right'Address then return Empty_Set; end if; if Left.Length = 0 then return Empty_Set; end if; if Right.Length = 0 then return Left; end if; return Result : Set (Left.Length, To_Prime (Left.Length)) do Iterate_Left : declare procedure Process (L_Node : Count_Type); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (L_Node : Count_Type) is N : Node_Type renames Left.Nodes (L_Node); X : Count_Type; B : Boolean; begin if not Is_In (Right, N) then Insert (Result, N.Element, X, B); -- optimize this ??? pragma Assert (B); pragma Assert (X > 0); end if; end Process; -- Start of processing for Iterate_Left begin Iterate (Left); end Iterate_Left; end return; end Difference; ------------- -- Element -- ------------- function Element (Position : Cursor) return Element_Type is begin if Position.Node = 0 then raise Constraint_Error with "Position cursor equals No_Element"; end if; pragma Assert (Vet (Position), "bad cursor in function Element"); declare S : Set renames Position.Container.all; N : Node_Type renames S.Nodes (Position.Node); begin return N.Element; end; end Element; --------------------- -- Equivalent_Sets -- --------------------- function Equivalent_Sets (Left, Right : Set) return Boolean is function Find_Equivalent_Key (R_HT : Hash_Table_Type'Class; L_Node : Node_Type) return Boolean; pragma Inline (Find_Equivalent_Key); function Is_Equivalent is new HT_Ops.Generic_Equal (Find_Equivalent_Key); ------------------------- -- Find_Equivalent_Key -- ------------------------- function Find_Equivalent_Key (R_HT : Hash_Table_Type'Class; L_Node : Node_Type) return Boolean is R_Index : constant Hash_Type := Element_Keys.Index (R_HT, L_Node.Element); R_Node : Count_Type := R_HT.Buckets (R_Index); RN : Nodes_Type renames R_HT.Nodes; begin loop if R_Node = 0 then return False; end if; if Equivalent_Elements (L_Node.Element, RN (R_Node).Element) then return True; end if; R_Node := Next (R_HT.Nodes (R_Node)); end loop; end Find_Equivalent_Key; -- Start of processing for Equivalent_Sets begin return Is_Equivalent (Left, Right); end Equivalent_Sets; ------------------------- -- Equivalent_Elements -- ------------------------- function Equivalent_Elements (Left, Right : Cursor) return Boolean is begin if Left.Node = 0 then raise Constraint_Error with "Left cursor of Equivalent_Elements equals No_Element"; end if; if Right.Node = 0 then raise Constraint_Error with "Right cursor of Equivalent_Elements equals No_Element"; end if; pragma Assert (Vet (Left), "bad Left cursor in Equivalent_Elements"); pragma Assert (Vet (Right), "bad Right cursor in Equivalent_Elements"); -- AI05-0022 requires that a container implementation detect element -- tampering by a generic actual subprogram. However, the following case -- falls outside the scope of that AI. Randy Brukardt explained on the -- ARG list on 2013/02/07 that: -- (Begin Quote): -- But for an operation like "<" [the ordered set analog of -- Equivalent_Elements], there is no need to "dereference" a cursor -- after the call to the generic formal parameter function, so nothing -- bad could happen if tampering is undetected. And the operation can -- safely return a result without a problem even if an element is -- deleted from the container. -- (End Quote). declare LN : Node_Type renames Left.Container.Nodes (Left.Node); RN : Node_Type renames Right.Container.Nodes (Right.Node); begin return Equivalent_Elements (LN.Element, RN.Element); end; end Equivalent_Elements; function Equivalent_Elements (Left : Cursor; Right : Element_Type) return Boolean is begin if Left.Node = 0 then raise Constraint_Error with "Left cursor of Equivalent_Elements equals No_Element"; end if; pragma Assert (Vet (Left), "Left cursor in Equivalent_Elements is bad"); declare LN : Node_Type renames Left.Container.Nodes (Left.Node); begin return Equivalent_Elements (LN.Element, Right); end; end Equivalent_Elements; function Equivalent_Elements (Left : Element_Type; Right : Cursor) return Boolean is begin if Right.Node = 0 then raise Constraint_Error with "Right cursor of Equivalent_Elements equals No_Element"; end if; pragma Assert (Vet (Right), "Right cursor of Equivalent_Elements is bad"); declare RN : Node_Type renames Right.Container.Nodes (Right.Node); begin return Equivalent_Elements (Left, RN.Element); end; end Equivalent_Elements; --------------------- -- Equivalent_Keys -- --------------------- function Equivalent_Keys (Key : Element_Type; Node : Node_Type) return Boolean is begin return Equivalent_Elements (Key, Node.Element); end Equivalent_Keys; ------------- -- Exclude -- ------------- procedure Exclude (Container : in out Set; Item : Element_Type) is X : Count_Type; begin Element_Keys.Delete_Key_Sans_Free (Container, Item, X); HT_Ops.Free (Container, X); end Exclude; -------------- -- Finalize -- -------------- procedure Finalize (Object : in out Iterator) is begin if Object.Container /= null then declare B : Natural renames Object.Container.all.Busy; begin B := B - 1; end; end if; end Finalize; ---------- -- Find -- ---------- function Find (Container : Set; Item : Element_Type) return Cursor is Node : constant Count_Type := Element_Keys.Find (Container'Unrestricted_Access.all, Item); begin return (if Node = 0 then No_Element else Cursor'(Container'Unrestricted_Access, Node)); end Find; ----------- -- First -- ----------- function First (Container : Set) return Cursor is Node : constant Count_Type := HT_Ops.First (Container); begin return (if Node = 0 then No_Element else Cursor'(Container'Unrestricted_Access, Node)); end First; overriding function First (Object : Iterator) return Cursor is begin return Object.Container.First; end First; ----------------- -- 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; --------------- -- Hash_Node -- --------------- function Hash_Node (Node : Node_Type) return Hash_Type is begin return Hash (Node.Element); end Hash_Node; ------------- -- Include -- ------------- procedure Include (Container : in out Set; New_Item : Element_Type) is Position : Cursor; Inserted : Boolean; begin Insert (Container, New_Item, Position, Inserted); if not Inserted then if Container.Lock > 0 then raise Program_Error with "attempt to tamper with elements (set is locked)"; end if; Container.Nodes (Position.Node).Element := New_Item; end if; end Include; ------------ -- Insert -- ------------ procedure Insert (Container : in out Set; New_Item : Element_Type; Position : out Cursor; Inserted : out Boolean) is begin Insert (Container, New_Item, Position.Node, Inserted); Position.Container := Container'Unchecked_Access; end Insert; procedure Insert (Container : in out Set; New_Item : Element_Type) is Position : Cursor; pragma Unreferenced (Position); Inserted : Boolean; begin Insert (Container, New_Item, Position, Inserted); if not Inserted then raise Constraint_Error with "attempt to insert element already in set"; end if; end Insert; procedure Insert (Container : in out Set; New_Item : Element_Type; Node : out Count_Type; Inserted : out Boolean) is procedure Allocate_Set_Element (Node : in out Node_Type); pragma Inline (Allocate_Set_Element); function New_Node return Count_Type; pragma Inline (New_Node); procedure Local_Insert is new Element_Keys.Generic_Conditional_Insert (New_Node); procedure Allocate is new HT_Ops.Generic_Allocate (Allocate_Set_Element); --------------------------- -- Allocate_Set_Element -- --------------------------- procedure Allocate_Set_Element (Node : in out Node_Type) is begin Node.Element := New_Item; end Allocate_Set_Element; -------------- -- New_Node -- -------------- function New_Node return Count_Type is Result : Count_Type; begin Allocate (Container, Result); return Result; end New_Node; -- Start of processing for Insert begin -- The buckets array length is specified by the user as a discriminant -- of the container type, so it is possible for the buckets array to -- have a length of zero. We must check for this case specifically, in -- order to prevent divide-by-zero errors later, when we compute the -- buckets array index value for an element, given its hash value. if Container.Buckets'Length = 0 then raise Capacity_Error with "No capacity for insertion"; end if; Local_Insert (Container, New_Item, Node, Inserted); end Insert; ------------------ -- Intersection -- ------------------ procedure Intersection (Target : in out Set; Source : Set) is Tgt_Node : Count_Type; TN : Nodes_Type renames Target.Nodes; begin if Target'Address = Source'Address then return; end if; if Source.Length = 0 then HT_Ops.Clear (Target); return; end if; if Target.Busy > 0 then raise Program_Error with "attempt to tamper with cursors (set is busy)"; end if; Tgt_Node := HT_Ops.First (Target); while Tgt_Node /= 0 loop if Is_In (Source, TN (Tgt_Node)) then Tgt_Node := HT_Ops.Next (Target, Tgt_Node); else declare X : constant Count_Type := Tgt_Node; begin Tgt_Node := HT_Ops.Next (Target, Tgt_Node); HT_Ops.Delete_Node_Sans_Free (Target, X); HT_Ops.Free (Target, X); end; end if; end loop; end Intersection; function Intersection (Left, Right : Set) return Set is C : Count_Type; begin if Left'Address = Right'Address then return Left; end if; C := Count_Type'Min (Left.Length, Right.Length); if C = 0 then return Empty_Set; end if; return Result : Set (C, To_Prime (C)) do Iterate_Left : declare procedure Process (L_Node : Count_Type); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (L_Node : Count_Type) is N : Node_Type renames Left.Nodes (L_Node); X : Count_Type; B : Boolean; begin if Is_In (Right, N) then Insert (Result, N.Element, X, B); -- optimize ??? pragma Assert (B); pragma Assert (X > 0); end if; end Process; -- Start of processing for Iterate_Left begin Iterate (Left); end Iterate_Left; end return; end Intersection; -------------- -- Is_Empty -- -------------- function Is_Empty (Container : Set) return Boolean is begin return Container.Length = 0; end Is_Empty; ----------- -- Is_In -- ----------- function Is_In (HT : Set; Key : Node_Type) return Boolean is begin return Element_Keys.Find (HT'Unrestricted_Access.all, Key.Element) /= 0; end Is_In; --------------- -- Is_Subset -- --------------- function Is_Subset (Subset : Set; Of_Set : Set) return Boolean is Subset_Node : Count_Type; SN : Nodes_Type renames Subset.Nodes; begin if Subset'Address = Of_Set'Address then return True; end if; if Subset.Length > Of_Set.Length then return False; end if; Subset_Node := HT_Ops.First (Subset); while Subset_Node /= 0 loop if not Is_In (Of_Set, SN (Subset_Node)) then return False; end if; Subset_Node := HT_Ops.Next (Subset'Unrestricted_Access.all, Subset_Node); end loop; return True; end Is_Subset; ------------- -- Iterate -- ------------- procedure Iterate (Container : Set; Process : not null access procedure (Position : Cursor)) is procedure Process_Node (Node : Count_Type); pragma Inline (Process_Node); procedure Iterate is new HT_Ops.Generic_Iteration (Process_Node); ------------------ -- Process_Node -- ------------------ procedure Process_Node (Node : Count_Type) is begin Process (Cursor'(Container'Unrestricted_Access, Node)); end Process_Node; B : Natural renames Container'Unrestricted_Access.all.Busy; -- Start of processing for Iterate begin B := B + 1; begin Iterate (Container); exception when others => B := B - 1; raise; end; B := B - 1; end Iterate; function Iterate (Container : Set) return Set_Iterator_Interfaces.Forward_Iterator'Class is B : Natural renames Container'Unrestricted_Access.all.Busy; begin B := B + 1; return It : constant Iterator := Iterator'(Limited_Controlled with Container => Container'Unrestricted_Access); end Iterate; ------------ -- Length -- ------------ function Length (Container : Set) return Count_Type is begin return Container.Length; end Length; ---------- -- Move -- ---------- procedure Move (Target : in out Set; Source : in out Set) is begin if Target'Address = Source'Address then return; end if; if Source.Busy > 0 then raise Program_Error with "attempt to tamper with cursors (container is busy)"; end if; Target.Assign (Source); Source.Clear; end Move; ---------- -- Next -- ---------- function Next (Node : Node_Type) return Count_Type is begin return Node.Next; 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 HT : Set renames Position.Container.all; Node : constant Count_Type := HT_Ops.Next (HT, Position.Node); begin if Node = 0 then return No_Element; end if; return Cursor'(Position.Container, Node); end; end Next; procedure Next (Position : in out Cursor) is begin Position := Next (Position); end Next; function Next (Object : Iterator; Position : Cursor) return Cursor is begin if Position.Container = null then return No_Element; end if; if Position.Container /= Object.Container then raise Program_Error with "Position cursor of Next designates wrong set"; end if; return Next (Position); end Next; ------------- -- Overlap -- ------------- function Overlap (Left, Right : Set) return Boolean is Left_Node : Count_Type; begin if Right.Length = 0 then return False; end if; if Left'Address = Right'Address then return True; end if; Left_Node := HT_Ops.First (Left); while Left_Node /= 0 loop if Is_In (Right, Left.Nodes (Left_Node)) then return True; end if; Left_Node := HT_Ops.Next (Left'Unrestricted_Access.all, Left_Node); end loop; return False; end Overlap; ------------------- -- 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 with "Position cursor of Query_Element equals No_Element"; end if; pragma Assert (Vet (Position), "bad cursor in Query_Element"); declare S : Set renames Position.Container.all; B : Natural renames S.Busy; L : Natural renames S.Lock; begin B := B + 1; L := L + 1; begin Process (S.Nodes (Position.Node).Element); 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 : not null access Root_Stream_Type'Class; Container : out Set) is function Read_Node (Stream : not null access Root_Stream_Type'Class) return Count_Type; procedure Read_Nodes is new HT_Ops.Generic_Read (Read_Node); --------------- -- Read_Node -- --------------- function Read_Node (Stream : not null access Root_Stream_Type'Class) return Count_Type is procedure Read_Element (Node : in out Node_Type); pragma Inline (Read_Element); procedure Allocate is new HT_Ops.Generic_Allocate (Read_Element); procedure Read_Element (Node : in out Node_Type) is begin Element_Type'Read (Stream, Node.Element); end Read_Element; Node : Count_Type; -- Start of processing for Read_Node begin Allocate (Container, Node); return Node; end Read_Node; -- Start of processing for Read begin Read_Nodes (Stream, Container); end Read; procedure Read (Stream : not null access Root_Stream_Type'Class; Item : out Cursor) is begin raise Program_Error with "attempt to stream set cursor"; end Read; procedure Read (Stream : not null access Root_Stream_Type'Class; Item : out Constant_Reference_Type) is begin raise Program_Error with "attempt to stream reference"; end Read; ------------- -- Replace -- ------------- procedure Replace (Container : in out Set; New_Item : Element_Type) is Node : constant Count_Type := Element_Keys.Find (Container, New_Item); begin if Node = 0 then raise Constraint_Error with "attempt to replace element not in set"; end if; if Container.Lock > 0 then raise Program_Error with "attempt to tamper with elements (set is locked)"; end if; Container.Nodes (Node).Element := New_Item; end Replace; procedure Replace_Element (Container : in out Set; Position : Cursor; New_Item : Element_Type) is begin if Position.Node = 0 then raise Constraint_Error with "Position cursor equals No_Element"; end if; if Position.Container /= Container'Unrestricted_Access then raise Program_Error with "Position cursor designates wrong set"; end if; pragma Assert (Vet (Position), "bad cursor in Replace_Element"); Replace_Element (Container, Position.Node, New_Item); end Replace_Element; ---------------------- -- Reserve_Capacity -- ---------------------- procedure Reserve_Capacity (Container : in out Set; Capacity : Count_Type) is begin if Capacity > Container.Capacity then raise Capacity_Error with "requested capacity is too large"; end if; end Reserve_Capacity; ------------------ -- Set_Element -- ------------------ procedure Set_Element (Node : in out Node_Type; Item : Element_Type) is begin Node.Element := Item; end Set_Element; -------------- -- Set_Next -- -------------- procedure Set_Next (Node : in out Node_Type; Next : Count_Type) is begin Node.Next := Next; end Set_Next; -------------------------- -- Symmetric_Difference -- -------------------------- procedure Symmetric_Difference (Target : in out Set; Source : Set) is procedure Process (Source_Node : Count_Type); pragma Inline (Process); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (Source_Node : Count_Type) is N : Node_Type renames Source.Nodes (Source_Node); X : Count_Type; B : Boolean; begin if Is_In (Target, N) then Delete (Target, N.Element); else Insert (Target, N.Element, X, B); pragma Assert (B); end if; end Process; -- Start of processing for Symmetric_Difference begin if Target'Address = Source'Address then HT_Ops.Clear (Target); return; end if; if Target.Length = 0 then Assign (Target => Target, Source => Source); return; end if; if Target.Busy > 0 then raise Program_Error with "attempt to tamper with cursors (set is busy)"; end if; Iterate (Source); end Symmetric_Difference; function Symmetric_Difference (Left, Right : Set) return Set is C : Count_Type; begin if Left'Address = Right'Address then return Empty_Set; end if; if Right.Length = 0 then return Left; end if; if Left.Length = 0 then return Right; end if; C := Left.Length + Right.Length; return Result : Set (C, To_Prime (C)) do Iterate_Left : declare procedure Process (L_Node : Count_Type); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (L_Node : Count_Type) is N : Node_Type renames Left.Nodes (L_Node); X : Count_Type; B : Boolean; begin if not Is_In (Right, N) then Insert (Result, N.Element, X, B); pragma Assert (B); end if; end Process; -- Start of processing for Iterate_Left begin Iterate (Left); end Iterate_Left; Iterate_Right : declare procedure Process (R_Node : Count_Type); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (R_Node : Count_Type) is N : Node_Type renames Right.Nodes (R_Node); X : Count_Type; B : Boolean; begin if not Is_In (Left, N) then Insert (Result, N.Element, X, B); pragma Assert (B); end if; end Process; -- Start of processing for Iterate_Right begin Iterate (Right); end Iterate_Right; end return; end Symmetric_Difference; ------------ -- To_Set -- ------------ function To_Set (New_Item : Element_Type) return Set is X : Count_Type; B : Boolean; begin return Result : Set (1, 1) do Insert (Result, New_Item, X, B); pragma Assert (B); end return; end To_Set; ----------- -- Union -- ----------- procedure Union (Target : in out Set; Source : Set) is procedure Process (Src_Node : Count_Type); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (Src_Node : Count_Type) is N : Node_Type renames Source.Nodes (Src_Node); X : Count_Type; B : Boolean; begin Insert (Target, N.Element, X, B); end Process; -- Start of processing for Union begin if Target'Address = Source'Address then return; end if; if Target.Busy > 0 then raise Program_Error with "attempt to tamper with cursors (set is busy)"; end if; -- ??? why is this code commented out ??? -- declare -- N : constant Count_Type := Target.Length + Source.Length; -- begin -- if N > HT_Ops.Capacity (Target.HT) then -- HT_Ops.Reserve_Capacity (Target.HT, N); -- end if; -- end; Iterate (Source); end Union; function Union (Left, Right : Set) return Set is C : Count_Type; begin if Left'Address = Right'Address then return Left; end if; if Right.Length = 0 then return Left; end if; if Left.Length = 0 then return Right; end if; C := Left.Length + Right.Length; return Result : Set (C, To_Prime (C)) do Assign (Target => Result, Source => Left); Union (Target => Result, Source => Right); end return; end Union; --------- -- 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 S : Set renames Position.Container.all; N : Nodes_Type renames S.Nodes; X : Count_Type; begin if S.Length = 0 then return False; end if; if Position.Node > N'Last then return False; end if; if N (Position.Node).Next = Position.Node then return False; end if; X := S.Buckets (Element_Keys.Checked_Index (S, N (Position.Node).Element)); for J in 1 .. S.Length loop if X = Position.Node then return True; end if; if X = 0 then return False; end if; if X = N (X).Next then -- to prevent unnecessary looping return False; end if; X := N (X).Next; end loop; return False; end; end Vet; ----------- -- Write -- ----------- procedure Write (Stream : not null access Root_Stream_Type'Class; Container : Set) is procedure Write_Node (Stream : not null access Root_Stream_Type'Class; Node : Node_Type); pragma Inline (Write_Node); procedure Write_Nodes is new HT_Ops.Generic_Write (Write_Node); ---------------- -- Write_Node -- ---------------- procedure Write_Node (Stream : not null access Root_Stream_Type'Class; Node : Node_Type) is begin Element_Type'Write (Stream, Node.Element); end Write_Node; -- Start of processing for Write begin Write_Nodes (Stream, Container); end Write; procedure Write (Stream : not null access Root_Stream_Type'Class; Item : Cursor) is begin raise Program_Error with "attempt to stream set cursor"; end Write; procedure Write (Stream : not null access Root_Stream_Type'Class; Item : Constant_Reference_Type) is begin raise Program_Error with "attempt to stream reference"; end Write; package body Generic_Keys is ----------------------- -- Local Subprograms -- ----------------------- function Equivalent_Key_Node (Key : Key_Type; Node : Node_Type) return Boolean; pragma Inline (Equivalent_Key_Node); -------------------------- -- Local Instantiations -- -------------------------- package Key_Keys is new Hash_Tables.Generic_Bounded_Keys (HT_Types => HT_Types, Next => Next, Set_Next => Set_Next, Key_Type => Key_Type, Hash => Hash, Equivalent_Keys => Equivalent_Key_Node); ------------------------ -- Constant_Reference -- ------------------------ function Constant_Reference (Container : aliased Set; Key : Key_Type) return Constant_Reference_Type is Node : constant Count_Type := Key_Keys.Find (Container'Unrestricted_Access.all, Key); begin if Node = 0 then raise Constraint_Error with "key not in set"; end if; declare N : Node_Type renames Container.Nodes (Node); begin return (Element => N.Element'Access); end; end Constant_Reference; -------------- -- Contains -- -------------- function Contains (Container : Set; Key : Key_Type) return Boolean is begin return Find (Container, Key) /= No_Element; end Contains; ------------ -- Delete -- ------------ procedure Delete (Container : in out Set; Key : Key_Type) is X : Count_Type; begin Key_Keys.Delete_Key_Sans_Free (Container, Key, X); if X = 0 then raise Constraint_Error with "attempt to delete key not in set"; end if; HT_Ops.Free (Container, X); end Delete; ------------- -- Element -- ------------- function Element (Container : Set; Key : Key_Type) return Element_Type is Node : constant Count_Type := Key_Keys.Find (Container'Unrestricted_Access.all, Key); begin if Node = 0 then raise Constraint_Error with "key not in set"; end if; return Container.Nodes (Node).Element; end Element; ------------------------- -- Equivalent_Key_Node -- ------------------------- function Equivalent_Key_Node (Key : Key_Type; Node : Node_Type) return Boolean is begin return Equivalent_Keys (Key, Generic_Keys.Key (Node.Element)); end Equivalent_Key_Node; ------------- -- Exclude -- ------------- procedure Exclude (Container : in out Set; Key : Key_Type) is X : Count_Type; begin Key_Keys.Delete_Key_Sans_Free (Container, Key, X); HT_Ops.Free (Container, X); end Exclude; ---------- -- Find -- ---------- function Find (Container : Set; Key : Key_Type) return Cursor is Node : constant Count_Type := Key_Keys.Find (Container'Unrestricted_Access.all, Key); begin return (if Node = 0 then No_Element else Cursor'(Container'Unrestricted_Access, Node)); end Find; --------- -- Key -- --------- function Key (Position : Cursor) return Key_Type is begin if Position.Node = 0 then raise Constraint_Error with "Position cursor equals No_Element"; end if; pragma Assert (Vet (Position), "bad cursor in function Key"); return Key (Position.Container.Nodes (Position.Node).Element); end Key; ---------- -- Read -- ---------- procedure Read (Stream : not null access Root_Stream_Type'Class; Item : out Reference_Type) is begin raise Program_Error with "attempt to stream reference"; end Read; ------------------------------ -- Reference_Preserving_Key -- ------------------------------ function Reference_Preserving_Key (Container : aliased in out Set; Position : Cursor) return Reference_Type is begin if Position.Container = null then raise Constraint_Error with "Position cursor has no element"; end if; if Position.Container /= Container'Unrestricted_Access then raise Program_Error with "Position cursor designates wrong container"; end if; pragma Assert (Vet (Position), "bad cursor in function Reference_Preserving_Key"); -- Some form of finalization will be required in order to actually -- check that the key-part of the element designated by Position has -- not changed. ??? declare N : Node_Type renames Container.Nodes (Position.Node); begin return (Element => N.Element'Access); end; end Reference_Preserving_Key; function Reference_Preserving_Key (Container : aliased in out Set; Key : Key_Type) return Reference_Type is Node : constant Count_Type := Key_Keys.Find (Container, Key); begin if Node = 0 then raise Constraint_Error with "key not in set"; end if; declare N : Node_Type renames Container.Nodes (Node); begin return (Element => N.Element'Access); end; end Reference_Preserving_Key; ------------- -- Replace -- ------------- procedure Replace (Container : in out Set; Key : Key_Type; New_Item : Element_Type) is Node : constant Count_Type := Key_Keys.Find (Container, Key); begin if Node = 0 then raise Constraint_Error with "attempt to replace key not in set"; end if; Replace_Element (Container, Node, New_Item); end Replace; ----------------------------------- -- Update_Element_Preserving_Key -- ----------------------------------- procedure Update_Element_Preserving_Key (Container : in out Set; Position : Cursor; Process : not null access procedure (Element : in out Element_Type)) is Indx : Hash_Type; N : Nodes_Type renames Container.Nodes; begin if Position.Node = 0 then raise Constraint_Error with "Position cursor equals No_Element"; end if; if Position.Container /= Container'Unrestricted_Access then raise Program_Error with "Position cursor designates wrong set"; end if; -- ??? why is this code commented out ??? -- if HT.Buckets = null -- or else HT.Buckets'Length = 0 -- or else HT.Length = 0 -- or else Position.Node.Next = Position.Node -- then -- raise Program_Error with -- "Position cursor is bad (set is empty)"; -- end if; pragma Assert (Vet (Position), "bad cursor in Update_Element_Preserving_Key"); -- Per AI05-0022, the container implementation is required to detect -- element tampering by a generic actual subprogram. declare E : Element_Type renames N (Position.Node).Element; K : constant Key_Type := Key (E); B : Natural renames Container.Busy; L : Natural renames Container.Lock; Eq : Boolean; begin B := B + 1; L := L + 1; begin -- Record bucket now, in case key is changed Indx := HT_Ops.Index (Container.Buckets, N (Position.Node)); Process (E); Eq := Equivalent_Keys (K, Key (E)); exception when others => L := L - 1; B := B - 1; raise; end; L := L - 1; B := B - 1; if Eq then return; end if; end; -- Key was modified, so remove this node from set. if Container.Buckets (Indx) = Position.Node then Container.Buckets (Indx) := N (Position.Node).Next; else declare Prev : Count_Type := Container.Buckets (Indx); begin while N (Prev).Next /= Position.Node loop Prev := N (Prev).Next; if Prev = 0 then raise Program_Error with "Position cursor is bad (node not found)"; end if; end loop; N (Prev).Next := N (Position.Node).Next; end; end if; Container.Length := Container.Length - 1; HT_Ops.Free (Container, Position.Node); raise Program_Error with "key was modified"; end Update_Element_Preserving_Key; ----------- -- Write -- ----------- procedure Write (Stream : not null access Root_Stream_Type'Class; Item : Reference_Type) is begin raise Program_Error with "attempt to stream reference"; end Write; end Generic_Keys; end Ada.Containers.Bounded_Hashed_Sets;