------------------------------------------------------------------------------ -- -- -- GNAT LIBRARY COMPONENTS -- -- -- -- A D A . C O N T A I N E R S . F O R M A L _ H A S H E D _ S E T S -- -- -- -- B o d y -- -- -- -- Copyright (C) 2010-2018, 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 -- -- . -- ------------------------------------------------------------------------------ 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.Formal_Hashed_Sets with SPARK_Mode => Off is ----------------------- -- Local Subprograms -- ----------------------- -- All need comments ??? procedure Difference (Left : Set; Right : Set; Target : in out Set); function Equivalent_Keys (Key : Element_Type; Node : Node_Type) return Boolean; pragma Inline (Equivalent_Keys); procedure Free (HT : in out Set; X : Count_Type); generic with procedure Set_Element (Node : in out Node_Type); procedure Generic_Allocate (HT : in out Set; Node : out Count_Type); 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); procedure Intersection (Left : Set; Right : Set; Target : in out Set); 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 (Container : Set; 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 begin if Length (Left) /= Length (Right) then return False; end if; if Length (Left) = 0 then return True; end if; declare Node : Count_Type; ENode : Count_Type; begin Node := First (Left).Node; while Node /= 0 loop ENode := Find (Container => Right, Item => Left.Nodes (Node).Element).Node; if ENode = 0 or else Right.Nodes (ENode).Element /= Left.Nodes (Node).Element then return False; end if; Node := HT_Ops.Next (Left, Node); end loop; return True; end; 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 < Length (Source) then raise Storage_Error with "not enough capacity"; -- SE or CE? ??? end if; HT_Ops.Clear (Target); Insert_Elements (Source); end Assign; -------------- -- Capacity -- -------------- function Capacity (Container : Set) return Count_Type is begin return Container.Nodes'Length; end Capacity; ----------- -- Clear -- ----------- procedure Clear (Container : in out Set) is begin HT_Ops.Clear (Container); end Clear; -------------- -- 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) return Set is C : constant Count_Type := Count_Type'Max (Capacity, Source.Capacity); Cu : Cursor; H : Hash_Type; N : Count_Type; Target : Set (C, Source.Modulus); begin if 0 < Capacity and then Capacity < Source.Capacity then raise Capacity_Error; end if; Target.Length := Source.Length; Target.Free := Source.Free; H := 1; while H <= Source.Modulus loop Target.Buckets (H) := Source.Buckets (H); H := H + 1; end loop; N := 1; while N <= Source.Capacity loop Target.Nodes (N) := Source.Nodes (N); N := N + 1; end loop; while N <= C loop Cu := (Node => N); Free (Target, Cu.Node); N := N + 1; end loop; return Target; 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; Free (Container, X); end Delete; procedure Delete (Container : in out Set; Position : in out Cursor) 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 Delete"); HT_Ops.Delete_Node_Sans_Free (Container, Position.Node); Free (Container, Position.Node); Position := No_Element; end Delete; ---------------- -- Difference -- ---------------- procedure Difference (Target : in out Set; Source : Set) is Src_Last : Count_Type; Src_Length : Count_Type; Src_Node : Count_Type; Tgt_Node : Count_Type; TN : Nodes_Type renames Target.Nodes; SN : Nodes_Type renames Source.Nodes; begin if Target'Address = Source'Address then Clear (Target); return; end if; Src_Length := Source.Length; if Src_Length = 0 then return; end if; if Src_Length >= Target.Length then Tgt_Node := HT_Ops.First (Target); while Tgt_Node /= 0 loop if Element_Keys.Find (Source, TN (Tgt_Node).Element) /= 0 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); Free (Target, X); end; else Tgt_Node := HT_Ops.Next (Target, Tgt_Node); end if; end loop; return; else Src_Node := HT_Ops.First (Source); Src_Last := 0; end if; while Src_Node /= Src_Last 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); Free (Target, Tgt_Node); end if; Src_Node := HT_Ops.Next (Source, Src_Node); end loop; end Difference; procedure Difference (Left : Set; Right : Set; Target : in out Set) is procedure Process (L_Node : Count_Type); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (L_Node : Count_Type) is B : Boolean; E : Element_Type renames Left.Nodes (L_Node).Element; X : Count_Type; begin if Find (Right, E).Node = 0 then Insert (Target, E, X, B); pragma Assert (B); end if; end Process; -- Start of processing for Difference begin Iterate (Left); end Difference; function Difference (Left : Set; Right : Set) return Set is C : Count_Type; H : Hash_Type; begin if Left'Address = Right'Address then return Empty_Set; end if; if Length (Left) = 0 then return Empty_Set; end if; if Length (Right) = 0 then return Left.Copy; end if; C := Length (Left); H := Default_Modulus (C); return S : Set (C, H) do Difference (Left, Right, Target => S); end return; end Difference; ------------- -- Element -- ------------- function Element (Container : Set; Position : Cursor) return Element_Type is begin if not Has_Element (Container, Position) then raise Constraint_Error with "Position cursor equals No_Element"; end if; pragma Assert (Vet (Container, Position), "bad cursor in function Element"); return Container.Nodes (Position.Node).Element; 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 := HT_Ops.Next (R_HT, R_Node); end loop; end Find_Equivalent_Key; -- Start of processing for Equivalent_Sets begin return Is_Equivalent (Left, Right); end Equivalent_Sets; --------------------- -- 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); Free (Container, X); end Exclude; ---------- -- Find -- ---------- function Find (Container : Set; Item : Element_Type) return Cursor is Node : constant Count_Type := Element_Keys.Find (Container, Item); begin if Node = 0 then return No_Element; end if; return (Node => Node); end Find; ----------- -- First -- ----------- function First (Container : Set) return Cursor is Node : constant Count_Type := HT_Ops.First (Container); begin if Node = 0 then return No_Element; end if; return (Node => Node); end First; ------------------ -- Formal_Model -- ------------------ package body Formal_Model is ------------------------- -- E_Elements_Included -- ------------------------- function E_Elements_Included (Left : E.Sequence; Right : E.Sequence) return Boolean is begin for I in 1 .. E.Length (Left) loop if not E.Contains (Right, 1, E.Length (Right), E.Get (Left, I)) then return False; end if; end loop; return True; end E_Elements_Included; function E_Elements_Included (Left : E.Sequence; Model : M.Set; Right : E.Sequence) return Boolean is begin for I in 1 .. E.Length (Left) loop declare Item : constant Element_Type := E.Get (Left, I); begin if M.Contains (Model, Item) then if not E.Contains (Right, 1, E.Length (Right), Item) then return False; end if; end if; end; end loop; return True; end E_Elements_Included; function E_Elements_Included (Container : E.Sequence; Model : M.Set; Left : E.Sequence; Right : E.Sequence) return Boolean is begin for I in 1 .. E.Length (Container) loop declare Item : constant Element_Type := E.Get (Container, I); begin if M.Contains (Model, Item) then if not E.Contains (Left, 1, E.Length (Left), Item) then return False; end if; else if not E.Contains (Right, 1, E.Length (Right), Item) then return False; end if; end if; end; end loop; return True; end E_Elements_Included; ---------- -- Find -- ---------- function Find (Container : E.Sequence; Item : Element_Type) return Count_Type is begin for I in 1 .. E.Length (Container) loop if Equivalent_Elements (Item, E.Get (Container, I)) then return I; end if; end loop; return 0; end Find; -------------- -- Elements -- -------------- function Elements (Container : Set) return E.Sequence is Position : Count_Type := HT_Ops.First (Container); R : E.Sequence; begin -- Can't use First, Next or Element here, since they depend on models -- for their postconditions. while Position /= 0 loop R := E.Add (R, Container.Nodes (Position).Element); Position := HT_Ops.Next (Container, Position); end loop; return R; end Elements; ---------------------------- -- Lift_Abstraction_Level -- ---------------------------- procedure Lift_Abstraction_Level (Container : Set) is null; ----------------------- -- Mapping_Preserved -- ----------------------- function Mapping_Preserved (E_Left : E.Sequence; E_Right : E.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) > E.Length (E_Left) or else P.Get (P_Right, C) > E.Length (E_Right) or else E.Get (E_Left, P.Get (P_Left, C)) /= E.Get (E_Right, P.Get (P_Right, C)) then return False; end if; end loop; return True; end Mapping_Preserved; ------------------------------ -- Mapping_Preserved_Except -- ------------------------------ function Mapping_Preserved_Except (E_Left : E.Sequence; E_Right : E.Sequence; P_Left : P.Map; P_Right : P.Map; Position : Cursor) return Boolean is begin for C of P_Left loop if C /= Position and (not P.Has_Key (P_Right, C) or else P.Get (P_Left, C) > E.Length (E_Left) or else P.Get (P_Right, C) > E.Length (E_Right) or else E.Get (E_Left, P.Get (P_Left, C)) /= E.Get (E_Right, P.Get (P_Right, C))) then return False; end if; end loop; return True; end Mapping_Preserved_Except; ----------- -- Model -- ----------- function Model (Container : Set) return M.Set is Position : Count_Type := HT_Ops.First (Container); R : M.Set; begin -- Can't use First, Next or Element here, since they depend on models -- for their postconditions. while Position /= 0 loop R := M.Add (Container => R, Item => Container.Nodes (Position).Element); Position := HT_Ops.Next (Container, Position); end loop; return R; end Model; --------------- -- Positions -- --------------- function Positions (Container : Set) return P.Map is I : Count_Type := 1; Position : Count_Type := HT_Ops.First (Container); 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) = I); Position := HT_Ops.Next (Container, Position); I := I + 1; end loop; return R; end Positions; end Formal_Model; ---------- -- Free -- ---------- procedure Free (HT : in out Set; X : Count_Type) is begin HT.Nodes (X).Has_Element := False; HT_Ops.Free (HT, X); end Free; ---------------------- -- Generic_Allocate -- ---------------------- procedure Generic_Allocate (HT : in out Set; Node : out Count_Type) is procedure Allocate is new HT_Ops.Generic_Allocate (Set_Element); begin Allocate (HT, Node); HT.Nodes (Node).Has_Element := True; end Generic_Allocate; package body Generic_Keys with SPARK_Mode => Off 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); -------------- -- 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; Free (Container, X); end Delete; ------------- -- Element -- ------------- function Element (Container : Set; Key : Key_Type) return Element_Type is Node : constant Count_Type := Find (Container, Key).Node; begin if Node = 0 then raise Constraint_Error with "key not in map"; 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); Free (Container, X); end Exclude; ---------- -- Find -- ---------- function Find (Container : Set; Key : Key_Type) return Cursor is Node : constant Count_Type := Key_Keys.Find (Container, Key); begin return (if Node = 0 then No_Element else (Node => Node)); end Find; ------------------ -- Formal_Model -- ------------------ package body Formal_Model is ----------------------- -- M_Included_Except -- ----------------------- function M_Included_Except (Left : M.Set; Right : M.Set; Key : Key_Type) return Boolean is begin for E of Left loop if not Contains (Right, E) and not Equivalent_Keys (Generic_Keys.Key (E), Key) then return False; end if; end loop; return True; end M_Included_Except; end Formal_Model; --------- -- Key -- --------- function Key (Container : Set; Position : Cursor) return Key_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 function Key"); declare N : Node_Type renames Container.Nodes (Position.Node); begin return Key (N.Element); end; end 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; end Generic_Keys; ----------------- -- Has_Element -- ----------------- function Has_Element (Container : Set; Position : Cursor) return Boolean is begin if Position.Node = 0 or else not Container.Nodes (Position.Node).Has_Element then return False; end if; return True; 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 Inserted : Boolean; Position : Cursor; begin Insert (Container, New_Item, Position, Inserted); if not Inserted then 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); end Insert; procedure Insert (Container : in out Set; New_Item : Element_Type) is Inserted : Boolean; Position : Cursor; 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 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 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 Clear (Target); return; end if; Tgt_Node := HT_Ops.First (Target); while Tgt_Node /= 0 loop if Find (Source, TN (Tgt_Node).Element).Node /= 0 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); Free (Target, X); end; end if; end loop; end Intersection; procedure Intersection (Left : Set; Right : Set; Target : in out Set) is procedure Process (L_Node : Count_Type); procedure Iterate is new HT_Ops.Generic_Iteration (Process); ------------- -- Process -- ------------- procedure Process (L_Node : Count_Type) is E : Element_Type renames Left.Nodes (L_Node).Element; X : Count_Type; B : Boolean; begin if Find (Right, E).Node /= 0 then Insert (Target, E, X, B); pragma Assert (B); end if; end Process; -- Start of processing for Intersection begin Iterate (Left); end Intersection; function Intersection (Left : Set; Right : Set) return Set is C : Count_Type; H : Hash_Type; begin if Left'Address = Right'Address then return Left.Copy; end if; C := Count_Type'Min (Length (Left), Length (Right)); -- ??? H := Default_Modulus (C); return S : Set (C, H) do if Length (Left) /= 0 and Length (Right) /= 0 then Intersection (Left, Right, Target => S); end if; end return; end Intersection; -------------- -- Is_Empty -- -------------- function Is_Empty (Container : Set) return Boolean is begin return Length (Container) = 0; end Is_Empty; ----------- -- Is_In -- ----------- function Is_In (HT : Set; Key : Node_Type) return Boolean is begin return Element_Keys.Find (HT, Key.Element) /= 0; end Is_In; --------------- -- Is_Subset -- --------------- function Is_Subset (Subset : Set; Of_Set : Set) return Boolean is Subset_Node : Count_Type; Subset_Nodes : Nodes_Type renames Subset.Nodes; begin if Subset'Address = Of_Set'Address then return True; end if; if Length (Subset) > Length (Of_Set) then return False; end if; Subset_Node := First (Subset).Node; while Subset_Node /= 0 loop declare N : Node_Type renames Subset_Nodes (Subset_Node); E : Element_Type renames N.Element; begin if Find (Of_Set, E).Node = 0 then return False; end if; end; Subset_Node := HT_Ops.Next (Subset, Subset_Node); end loop; return True; end Is_Subset; ------------ -- Length -- ------------ function Length (Container : Set) return Count_Type is begin return Container.Length; end Length; ---------- -- Move -- ---------- -- Comments??? procedure Move (Target : in out Set; Source : in out Set) is NN : HT_Types.Nodes_Type renames Source.Nodes; X, Y : Count_Type; begin if Target'Address = Source'Address then return; end if; if Target.Capacity < Length (Source) then raise Constraint_Error with -- ??? "Source length exceeds Target capacity"; end if; Clear (Target); if Source.Length = 0 then return; end if; X := HT_Ops.First (Source); while X /= 0 loop Insert (Target, NN (X).Element); -- optimize??? Y := HT_Ops.Next (Source, X); HT_Ops.Delete_Node_Sans_Free (Source, X); Free (Source, X); X := Y; end loop; end Move; ---------- -- Next -- ---------- function Next (Node : Node_Type) return Count_Type is begin return Node.Next; end Next; function Next (Container : Set; Position : Cursor) return Cursor is begin if Position.Node = 0 then return No_Element; end if; if not Has_Element (Container, Position) then raise Constraint_Error with "Position has no element"; end if; pragma Assert (Vet (Container, Position), "bad cursor in Next"); return (Node => HT_Ops.Next (Container, Position.Node)); end Next; procedure Next (Container : Set; Position : in out Cursor) is begin Position := Next (Container, Position); end Next; ------------- -- Overlap -- ------------- function Overlap (Left, Right : Set) return Boolean is Left_Node : Count_Type; Left_Nodes : Nodes_Type renames Left.Nodes; begin if Length (Right) = 0 or Length (Left) = 0 then return False; end if; if Left'Address = Right'Address then return True; end if; Left_Node := First (Left).Node; while Left_Node /= 0 loop declare N : Node_Type renames Left_Nodes (Left_Node); E : Element_Type renames N.Element; begin if Find (Right, E).Node /= 0 then return True; end if; end; Left_Node := HT_Ops.Next (Left, Left_Node); end loop; return False; end Overlap; ------------- -- 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; Container.Nodes (Node).Element := New_Item; end Replace; --------------------- -- Replace_Element -- --------------------- procedure Replace_Element (Container : in out Set; Position : Cursor; New_Item : Element_Type) is begin if not Has_Element (Container, Position) then raise Constraint_Error with "Position cursor equals No_Element"; end if; pragma Assert (Vet (Container, 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 Constraint_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 B : Boolean; N : Node_Type renames Source.Nodes (Source_Node); X : Count_Type; 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 Clear (Target); return; end if; if Length (Target) = 0 then Assign (Target, Source); return; end if; Iterate (Source); end Symmetric_Difference; function Symmetric_Difference (Left : Set; Right : Set) return Set is C : Count_Type; H : Hash_Type; begin if Left'Address = Right'Address then return Empty_Set; end if; if Length (Right) = 0 then return Left.Copy; end if; if Length (Left) = 0 then return Right.Copy; end if; C := Length (Left) + Length (Right); H := Default_Modulus (C); return S : Set (C, H) do Difference (Left, Right, S); Difference (Right, Left, S); end return; end Symmetric_Difference; ------------ -- To_Set -- ------------ function To_Set (New_Item : Element_Type) return Set is X : Count_Type; B : Boolean; begin return S : Set (Capacity => 1, Modulus => 1) do Insert (S, 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); E : Element_Type renames N.Element; X : Count_Type; B : Boolean; begin Insert (Target, E, X, B); end Process; -- Start of processing for Union begin if Target'Address = Source'Address then return; end if; Iterate (Source); end Union; function Union (Left : Set; Right : Set) return Set is C : Count_Type; H : Hash_Type; begin if Left'Address = Right'Address then return Left.Copy; end if; if Length (Right) = 0 then return Left.Copy; end if; if Length (Left) = 0 then return Right.Copy; end if; C := Length (Left) + Length (Right); H := Default_Modulus (C); return S : Set (C, H) do Assign (Target => S, Source => Left); Union (Target => S, Source => Right); end return; end Union; --------- -- Vet -- --------- function Vet (Container : Set; Position : Cursor) return Boolean is begin if Position.Node = 0 then return True; end if; declare S : Set renames Container; 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.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; end Ada.Containers.Formal_Hashed_Sets;