Patchwork [Ada] New units for bounded hashed set and map containers

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Submitter Arnaud Charlet
Date Oct. 26, 2010, 10:44 a.m.
Message ID <20101026104436.GA6299@adacore.com>
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Permalink /patch/69221/
State New
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Arnaud Charlet - Oct. 26, 2010, 10:44 a.m.
Ada 2012 added bounded versions of the container forms introduced
in Ada 2005; see AI05-0001 for more information. This change incorporates
the units for both the bounded hashed set container,
Ada.Containers.Bounded_Hashed_Sets, and the bounded hashed map container,
Ada.Containers.Bounded_Hashed_Maps.

Tested on x86_64-pc-linux-gnu, committed on trunk

2010-10-26  Matthew Heaney  <heaney@adacore.com>

	* Makefile.rtl, impunit.adb: Add bounded hashed set and bounded hashed
	map containers.
	* a-cohata.ads: Add declaration of generic package for bounded hash
	table types.
	* a-chtgbo.ads, a-chtgbo.adb, a-chtgbk.ads, a-chtgbk.adb, a-cbhase.ads,
	a-cbhase.adb, a-cbhama.ads, a-cbhama.adb: New files.

Patch

Index: impunit.adb
===================================================================
--- impunit.adb	(revision 165938)
+++ impunit.adb	(working copy)
@@ -510,7 +510,9 @@  package body Impunit is
      "a-cobove",    -- Ada.Containers.Bounded_Vectors
      "a-cbdlli",    -- Ada.Containers.Bounded_Doubly_Linked_Lists
      "a-cborse",    -- Ada.Containers.Bounded_Ordered_Sets
-     "a-cborma");   -- Ada.Containers.Bounded_Ordered_Maps
+     "a-cborma",    -- Ada.Containers.Bounded_Ordered_Maps
+     "a-cbhase",    -- Ada.Containers.Bounded_Hashed_Sets
+     "a-cbhama");   -- Ada.Containers.Bounded_Hashed_Maps
 
    -----------------------
    -- Alternative Units --
Index: a-cohata.ads
===================================================================
--- a-cohata.ads	(revision 165935)
+++ a-cohata.ads	(working copy)
@@ -6,7 +6,7 @@ 
 --                                                                          --
 --                                 S p e c                                  --
 --                                                                          --
---          Copyright (C) 2004-2009, Free Software Foundation, Inc.         --
+--          Copyright (C) 2004-2010, 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- --
@@ -52,4 +52,23 @@  package Ada.Containers.Hash_Tables is
       end record;
    end Generic_Hash_Table_Types;
 
+   generic
+      type Node_Type is private;
+   package Generic_Bounded_Hash_Table_Types is
+      type Nodes_Type is array (Count_Type range <>) of Node_Type;
+      type Buckets_Type is array (Hash_Type range <>) of Count_Type;
+
+      type Hash_Table_Type
+        (Capacity : Count_Type;
+         Modulus  : Hash_Type) is
+      tagged record
+         Length  : Count_Type := 0;
+         Busy    : Natural := 0;
+         Lock    : Natural := 0;
+         Free    : Count_Type'Base := -1;
+         Nodes   : Nodes_Type (1 .. Capacity);
+         Buckets : Buckets_Type (1 .. Modulus) := (others => 0);
+      end record;
+   end Generic_Bounded_Hash_Table_Types;
+
 end Ada.Containers.Hash_Tables;
Index: a-cbhama.adb
===================================================================
--- a-cbhama.adb	(revision 0)
+++ a-cbhama.adb	(revision 0)
@@ -0,0 +1,1068 @@ 
+------------------------------------------------------------------------------
+--                                                                          --
+--                         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 _ M A P S    --
+--                                                                          --
+--                                 B o d y                                  --
+--                                                                          --
+--          Copyright (C) 2004-2010, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+with 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_Maps is
+
+   -----------------------
+   -- Local Subprograms --
+   -----------------------
+
+   function Equivalent_Key_Node
+     (Key  : Key_Type;
+      Node : Node_Type) return Boolean;
+   pragma Inline (Equivalent_Key_Node);
+
+   function Hash_Node (Node : Node_Type) return Hash_Type;
+   pragma Inline (Hash_Node);
+
+   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 Key_Ops 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);
+
+   ---------
+   -- "=" --
+   ---------
+
+   function "=" (Left, Right : Map) return Boolean is
+      function Find_Equal_Key
+        (R_HT   : Hash_Table_Type'Class;
+         L_Node : Node_Type) return Boolean;
+
+      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 := Key_Ops.Index (R_HT, L_Node.Key);
+         R_Node  : Count_Type := R_HT.Buckets (R_Index);
+
+      begin
+         while R_Node /= 0 loop
+            if Equivalent_Keys (L_Node.Key, R_HT.Nodes (R_Node).Key) then
+               return L_Node.Element = R_HT.Nodes (R_Node).Element;
+            end if;
+
+            R_Node := R_HT.Nodes (R_Node).Next;
+         end loop;
+
+         return False;
+      end Find_Equal_Key;
+
+   --  Start of processing for "="
+
+   begin
+      return Is_Equal (Left, Right);
+   end "=";
+
+   ------------
+   -- Assign --
+   ------------
+
+   procedure Assign (Target : in out Map; Source : Map) 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);
+         C : Cursor;
+         B : Boolean;
+
+      begin
+         Insert (Target, N.Key, N.Element, C, 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 : Map) return Count_Type is
+   begin
+      return Container.Capacity;
+   end Capacity;
+
+   -----------
+   -- Clear --
+   -----------
+
+   procedure Clear (Container : in out Map) is
+   begin
+      HT_Ops.Clear (Container);
+   end Clear;
+
+   --------------
+   -- Contains --
+   --------------
+
+   function Contains (Container : Map; Key : Key_Type) return Boolean is
+   begin
+      return Find (Container, Key) /= No_Element;
+   end Contains;
+
+   ----------
+   -- Copy --
+   ----------
+
+   function Copy
+     (Source   : Map;
+      Capacity : Count_Type := 0;
+      Modulus  : Hash_Type := 0) return Map
+   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 : Map (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 Map; Key : Key_Type) is
+      X : Count_Type;
+
+   begin
+      Key_Ops.Delete_Key_Sans_Free (Container, Key, X);
+
+      if X = 0 then
+         raise Constraint_Error with "attempt to delete key not in map";
+      end if;
+
+      HT_Ops.Free (Container, X);
+   end Delete;
+
+   procedure Delete (Container : in out Map; Position : in out Cursor) is
+   begin
+      if Position.Node = 0 then
+         raise Constraint_Error with
+           "Position cursor of Delete equals No_Element";
+      end if;
+
+      if Position.Container /= Container'Unrestricted_Access then
+         raise Program_Error with
+           "Position cursor of Delete designates wrong map";
+      end if;
+
+      if Container.Busy > 0 then
+         raise Program_Error with
+           "Delete attempted to tamper with cursors (map 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;
+
+   -------------
+   -- Element --
+   -------------
+
+   function Element (Container : Map; Key : Key_Type) return Element_Type is
+      Node : constant Count_Type := Key_Ops.Find (Container, Key);
+
+   begin
+      if Node = 0 then
+         raise Constraint_Error with
+           "no element available because key not in map";
+      end if;
+
+      return Container.Nodes (Node).Element;
+   end Element;
+
+   function Element (Position : Cursor) return Element_Type is
+   begin
+      if Position.Node = 0 then
+         raise Constraint_Error with
+           "Position cursor of function Element equals No_Element";
+      end if;
+
+      pragma Assert (Vet (Position), "bad cursor in function Element");
+
+      return Position.Container.Nodes (Position.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, Node.Key);
+   end Equivalent_Key_Node;
+
+   ---------------------
+   -- Equivalent_Keys --
+   ---------------------
+
+   function Equivalent_Keys (Left, Right : Cursor)
+     return Boolean is
+   begin
+      if Left.Node = 0 then
+         raise Constraint_Error with
+           "Left cursor of Equivalent_Keys equals No_Element";
+      end if;
+
+      if Right.Node = 0 then
+         raise Constraint_Error with
+           "Right cursor of Equivalent_Keys equals No_Element";
+      end if;
+
+      pragma Assert (Vet (Left), "Left cursor of Equivalent_Keys is bad");
+      pragma Assert (Vet (Right), "Right cursor of Equivalent_Keys is bad");
+
+      declare
+         LN : Node_Type renames Left.Container.Nodes (Left.Node);
+         RN : Node_Type renames Right.Container.Nodes (Right.Node);
+
+      begin
+         return Equivalent_Keys (LN.Key, RN.Key);
+      end;
+   end Equivalent_Keys;
+
+   function Equivalent_Keys (Left : Cursor; Right : Key_Type) return Boolean is
+   begin
+      if Left.Node = 0 then
+         raise Constraint_Error with
+           "Left cursor of Equivalent_Keys equals No_Element";
+      end if;
+
+      pragma Assert (Vet (Left), "Left cursor in Equivalent_Keys is bad");
+
+      declare
+         LN : Node_Type renames Left.Container.Nodes (Left.Node);
+
+      begin
+         return Equivalent_Keys (LN.Key, Right);
+      end;
+   end Equivalent_Keys;
+
+   function Equivalent_Keys (Left : Key_Type; Right : Cursor) return Boolean is
+   begin
+      if Right.Node = 0 then
+         raise Constraint_Error with
+           "Right cursor of Equivalent_Keys equals No_Element";
+      end if;
+
+      pragma Assert (Vet (Right), "Right cursor of Equivalent_Keys is bad");
+
+      declare
+         RN : Node_Type renames Right.Container.Nodes (Right.Node);
+
+      begin
+         return Equivalent_Keys (Left, RN.Key);
+      end;
+   end Equivalent_Keys;
+
+   -------------
+   -- Exclude --
+   -------------
+
+   procedure Exclude (Container : in out Map; Key : Key_Type) is
+      X : Count_Type;
+   begin
+      Key_Ops.Delete_Key_Sans_Free (Container, Key, X);
+      HT_Ops.Free (Container, X);
+   end Exclude;
+
+   ----------
+   -- Find --
+   ----------
+
+   function Find (Container : Map; Key : Key_Type) return Cursor is
+      Node : constant Count_Type := Key_Ops.Find (Container, Key);
+
+   begin
+      if Node = 0 then
+         return No_Element;
+      end if;
+
+      return Cursor'(Container'Unrestricted_Access, Node);
+   end Find;
+
+   -----------
+   -- First --
+   -----------
+
+   function First (Container : Map) return Cursor is
+      Node : constant Count_Type := HT_Ops.First (Container);
+
+   begin
+      if Node = 0 then
+         return No_Element;
+      end if;
+
+      return Cursor'(Container'Unrestricted_Access, Node);
+   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.Key);
+   end Hash_Node;
+
+   -------------
+   -- Include --
+   -------------
+
+   procedure Include
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type)
+   is
+      Position : Cursor;
+      Inserted : Boolean;
+
+   begin
+      Insert (Container, Key, New_Item, Position, Inserted);
+
+      if not Inserted then
+         if Container.Lock > 0 then
+            raise Program_Error with
+              "Include attempted to tamper with elements (map is locked)";
+         end if;
+
+         declare
+            N : Node_Type renames Container.Nodes (Position.Node);
+
+         begin
+            N.Key := Key;
+            N.Element := New_Item;
+         end;
+      end if;
+   end Include;
+
+   ------------
+   -- Insert --
+   ------------
+
+   procedure Insert
+     (Container : in out Map;
+      Key       : Key_Type;
+      Position  : out Cursor;
+      Inserted  : out Boolean)
+   is
+      procedure Assign_Key (Node : in out Node_Type);
+      pragma Inline (Assign_Key);
+
+      function New_Node return Count_Type;
+      pragma Inline (New_Node);
+
+      procedure Local_Insert is
+        new Key_Ops.Generic_Conditional_Insert (New_Node);
+
+      procedure Allocate is
+         new HT_Ops.Generic_Allocate (Assign_Key);
+
+      -----------------
+      --  Assign_Key --
+      -----------------
+
+      procedure Assign_Key (Node : in out Node_Type) is
+      begin
+         Node.Key := Key;
+         --  Node.Element := New_Item;
+      end Assign_Key;
+
+      --------------
+      -- 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
+      --  ???
+      --  if HT_Ops.Capacity (HT) = 0 then
+      --     HT_Ops.Reserve_Capacity (HT, 1);
+      --  end if;
+
+      Local_Insert (Container, Key, Position.Node, Inserted);
+
+      --  ???
+      --  if Inserted
+      --    and then HT.Length > HT_Ops.Capacity (HT)
+      --  then
+      --     HT_Ops.Reserve_Capacity (HT, HT.Length);
+      --  end if;
+
+      Position.Container := Container'Unchecked_Access;
+   end Insert;
+
+   procedure Insert
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type;
+      Position  : out Cursor;
+      Inserted  : out Boolean)
+   is
+      procedure Assign_Key (Node : in out Node_Type);
+      pragma Inline (Assign_Key);
+
+      function New_Node return Count_Type;
+      pragma Inline (New_Node);
+
+      procedure Local_Insert is
+        new Key_Ops.Generic_Conditional_Insert (New_Node);
+
+      procedure Allocate is
+         new HT_Ops.Generic_Allocate (Assign_Key);
+
+      -----------------
+      --  Assign_Key --
+      -----------------
+
+      procedure Assign_Key (Node : in out Node_Type) is
+      begin
+         Node.Key := Key;
+         Node.Element := New_Item;
+      end Assign_Key;
+
+      --------------
+      -- 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
+      --  ??
+      --  if HT_Ops.Capacity (HT) = 0 then
+      --     HT_Ops.Reserve_Capacity (HT, 1);
+      --  end if;
+
+      Local_Insert (Container, Key, Position.Node, Inserted);
+
+      --  ???
+      --  if Inserted
+      --    and then HT.Length > HT_Ops.Capacity (HT)
+      --  then
+      --     HT_Ops.Reserve_Capacity (HT, HT.Length);
+      --  end if;
+
+      Position.Container := Container'Unchecked_Access;
+   end Insert;
+
+   procedure Insert
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type)
+   is
+      Position : Cursor;
+      pragma Unreferenced (Position);
+
+      Inserted : Boolean;
+
+   begin
+      Insert (Container, Key, New_Item, Position, Inserted);
+
+      if not Inserted then
+         raise Constraint_Error with
+           "attempt to insert key already in map";
+      end if;
+   end Insert;
+
+   --------------
+   -- Is_Empty --
+   --------------
+
+   function Is_Empty (Container : Map) return Boolean is
+   begin
+      return Container.Length = 0;
+   end Is_Empty;
+
+   -------------
+   -- Iterate --
+   -------------
+
+   procedure Iterate
+     (Container : Map;
+      Process   : not null access procedure (Position : Cursor))
+   is
+      procedure Process_Node (Node : Count_Type);
+      pragma Inline (Process_Node);
+
+      procedure Local_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.Busy;
+
+   --  Start of processing for Iterate
+
+   begin
+      B := B + 1;
+
+      begin
+         Local_Iterate (Container);
+      exception
+         when others =>
+            B := B - 1;
+            raise;
+      end;
+
+      B := B - 1;
+   end Iterate;
+
+   ---------
+   -- Key --
+   ---------
+
+   function Key (Position : Cursor) return Key_Type is
+   begin
+      if Position.Node = 0 then
+         raise Constraint_Error with
+           "Position cursor of function Key equals No_Element";
+      end if;
+
+      pragma Assert (Vet (Position), "bad cursor in function Key");
+
+      return Position.Container.Nodes (Position.Node).Key;
+   end Key;
+
+   ------------
+   -- Length --
+   ------------
+
+   function Length (Container : Map) return Count_Type is
+   begin
+      return Container.Length;
+   end Length;
+
+   ----------
+   -- Move --
+   ----------
+
+   procedure Move
+     (Target : in out Map;
+      Source : in out Map)
+   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;
+
+      Assign (Target => Target, Source => Source);
+   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 function Next");
+
+      declare
+         M    : Map renames Position.Container.all;
+         Node : constant Count_Type := HT_Ops.Next (M, 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;
+
+   -------------------
+   -- Query_Element --
+   -------------------
+
+   procedure Query_Element
+     (Position : Cursor;
+      Process  : not null access
+                   procedure (Key : Key_Type; 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
+         M : Map renames Position.Container.all;
+         N : Node_Type renames M.Nodes (Position.Node);
+         B : Natural renames M.Busy;
+         L : Natural renames M.Lock;
+
+      begin
+         B := B + 1;
+         L := L + 1;
+
+         declare
+
+         begin
+            Process (N.Key, N.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 Map)
+   is
+      function Read_Node
+        (Stream : not null access Root_Stream_Type'Class) return Count_Type;
+      --  pragma Inline (Read_Node);  ???
+
+      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
+            Key_Type'Read (Stream, Node.Key);
+            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 map cursor";
+   end Read;
+
+   -------------
+   -- Replace --
+   -------------
+
+   procedure Replace
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type)
+   is
+      Node : constant Count_Type := Key_Ops.Find (Container, Key);
+
+   begin
+      if Node = 0 then
+         raise Constraint_Error with
+           "attempt to replace key not in map";
+      end if;
+
+      if Container.Lock > 0 then
+         raise Program_Error with
+           "Replace attempted to tamper with elements (map is locked)";
+      end if;
+
+      declare
+         N : Node_Type renames Container.Nodes (Node);
+
+      begin
+         N.Key := Key;
+         N.Element := New_Item;
+      end;
+   end Replace;
+
+   ---------------------
+   -- Replace_Element --
+   ---------------------
+
+   procedure Replace_Element
+     (Container : in out Map;
+      Position  : Cursor;
+      New_Item  : Element_Type)
+   is
+   begin
+      if Position.Node = 0 then
+         raise Constraint_Error with
+           "Position cursor of Replace_Element equals No_Element";
+      end if;
+
+      if Position.Container /= Container'Unrestricted_Access then
+         raise Program_Error with
+           "Position cursor of Replace_Element designates wrong map";
+      end if;
+
+      if Position.Container.Lock > 0 then
+         raise Program_Error with
+           "Replace_Element attempted to tamper with elements (map is locked)";
+      end if;
+
+      pragma Assert (Vet (Position), "bad cursor in Replace_Element");
+
+      Container.Nodes (Position.Node).Element := New_Item;
+   end Replace_Element;
+
+   ----------------------
+   -- Reserve_Capacity --
+   ----------------------
+
+   procedure Reserve_Capacity
+     (Container : in out Map;
+      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_Next --
+   --------------
+
+   procedure Set_Next (Node : in out Node_Type; Next : Count_Type) is
+   begin
+      Node.Next := Next;
+   end Set_Next;
+
+   --------------------
+   -- Update_Element --
+   --------------------
+
+   procedure Update_Element
+     (Container : in out Map;
+      Position  : Cursor;
+      Process   : not null access procedure (Key     : Key_Type;
+                                             Element : in out Element_Type))
+   is
+   begin
+      if Position.Node = 0 then
+         raise Constraint_Error with
+           "Position cursor of Update_Element equals No_Element";
+      end if;
+
+      if Position.Container /= Container'Unrestricted_Access then
+         raise Program_Error with
+           "Position cursor of Update_Element designates wrong map";
+      end if;
+
+      pragma Assert (Vet (Position), "bad cursor in Update_Element");
+
+      declare
+         N : Node_Type renames Container.Nodes (Position.Node);
+         B : Natural renames Container.Busy;
+         L : Natural renames Container.Lock;
+
+      begin
+         B := B + 1;
+         L := L + 1;
+
+         begin
+            Process (N.Key, N.Element);
+         exception
+            when others =>
+               L := L - 1;
+               B := B - 1;
+               raise;
+         end;
+
+         L := L - 1;
+         B := B - 1;
+      end;
+   end Update_Element;
+
+   ---------
+   -- Vet --
+   ---------
+
+   function Vet (Position : Cursor) return Boolean is
+   begin
+      if Position.Node = 0 then
+         return Position.Container = null;
+      end if;
+
+      if Position.Container = null then
+         return False;
+      end if;
+
+      declare
+         M : Map renames Position.Container.all;
+         X : Count_Type;
+
+      begin
+         if M.Length = 0 then
+            return False;
+         end if;
+
+         if M.Capacity = 0 then
+            return False;
+         end if;
+
+         if M.Buckets'Length = 0 then
+            return False;
+         end if;
+
+         if Position.Node > M.Capacity then
+            return False;
+         end if;
+
+         if M.Nodes (Position.Node).Next = Position.Node then
+            return False;
+         end if;
+
+         X := M.Buckets (Key_Ops.Index (M, M.Nodes (Position.Node).Key));
+
+         for J in 1 .. M.Length loop
+            if X = Position.Node then
+               return True;
+            end if;
+
+            if X = 0 then
+               return False;
+            end if;
+
+            if X = M.Nodes (X).Next then  --  to prevent unnecessary looping
+               return False;
+            end if;
+
+            X := M.Nodes (X).Next;
+         end loop;
+
+         return False;
+      end;
+   end Vet;
+
+   -----------
+   -- Write --
+   -----------
+
+   procedure Write
+     (Stream    : not null access Root_Stream_Type'Class;
+      Container : Map)
+   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
+         Key_Type'Write (Stream, Node.Key);
+         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 map cursor";
+   end Write;
+
+end Ada.Containers.Bounded_Hashed_Maps;
Index: a-cbhama.ads
===================================================================
--- a-cbhama.ads	(revision 0)
+++ a-cbhama.ads	(revision 0)
@@ -0,0 +1,343 @@ 
+------------------------------------------------------------------------------
+--                                                                          --
+--                         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 _ M A P S    --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2004-2010, 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    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+private with Ada.Containers.Hash_Tables;
+private with Ada.Streams;
+
+generic
+   type Key_Type is private;
+   type Element_Type is private;
+
+   with function Hash (Key : Key_Type) return Hash_Type;
+   with function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
+   with function "=" (Left, Right : Element_Type) return Boolean is <>;
+
+package Ada.Containers.Bounded_Hashed_Maps is
+   pragma Pure;
+   pragma Remote_Types;
+
+   type Map (Capacity : Count_Type; Modulus : Hash_Type) is tagged private;
+   pragma Preelaborable_Initialization (Map);
+
+   type Cursor is private;
+   pragma Preelaborable_Initialization (Cursor);
+
+   Empty_Map : constant Map;
+   --  Map objects declared without an initialization expression are
+   --  initialized to the value Empty_Map.
+
+   No_Element : constant Cursor;
+   --  Cursor objects declared without an initialization expression are
+   --  initialized to the value No_Element.
+
+   function "=" (Left, Right : Map) return Boolean;
+   --  For each key/element pair in Left, equality attempts to find the key in
+   --  Right; if a search fails the equality returns False. The search works by
+   --  calling Hash to find the bucket in the Right map that corresponds to the
+   --  Left key. If bucket is non-empty, then equality calls Equivalent_Keys
+   --  to compare the key (in Left) to the key of each node in the bucket (in
+   --  Right); if the keys are equivalent, then the equality test for this
+   --  key/element pair (in Left) completes by calling the element equality
+   --  operator to compare the element (in Left) to the element of the node
+   --  (in Right) whose key matched.
+
+   function Capacity (Container : Map) return Count_Type;
+   --  Returns the current capacity of the map. Capacity is the maximum length
+   --  before which rehashing in guaranteed not to occur.
+
+   procedure Reserve_Capacity (Container : in out Map; Capacity : Count_Type);
+   --  If the value of the Capacity actual parameter is less or equal to
+   --  Container.Capacity, then the operation has no effect.  Otherwise it
+   --  raises Capacity_Error (as no expansion of capacity is possible for a
+   --  bounded form).
+
+   function Default_Modulus (Capacity : Count_Type) return Hash_Type;
+   --  Returns a modulus value (hash table size) which is optimal for the
+   --  specified capacity (which corresponds to the maximum number of items).
+
+   function Length (Container : Map) return Count_Type;
+   --  Returns the number of items in the map
+
+   function Is_Empty (Container : Map) return Boolean;
+   --  Equivalent to Length (Container) = 0
+
+   procedure Clear (Container : in out Map);
+   --  Removes all of the items from the map
+
+   function Key (Position : Cursor) return Key_Type;
+   --  Returns the key of the node designated by the cursor
+
+   function Element (Position : Cursor) return Element_Type;
+   --  Returns the element of the node designated by the cursor
+
+   procedure Replace_Element
+     (Container : in out Map;
+      Position  : Cursor;
+      New_Item  : Element_Type);
+   --  Assigns the value New_Item to the element designated by the cursor
+
+   procedure Query_Element
+     (Position : Cursor;
+      Process  : not null access
+                   procedure (Key : Key_Type; Element : Element_Type));
+   --  Calls Process with the key and element (both having only a constant
+   --  view) of the node designed by the cursor.
+
+   procedure Update_Element
+     (Container : in out Map;
+      Position  : Cursor;
+      Process   : not null access
+                    procedure (Key : Key_Type; Element : in out Element_Type));
+   --  Calls Process with the key (with only a constant view) and element (with
+   --  a variable view) of the node designed by the cursor.
+
+   procedure Assign (Target : in out Map; Source : Map);
+   --  If Target denotes the same object as Source, then the operation has no
+   --  effect. If the Target capacity is less then the Source length, then
+   --  Assign raises Capacity_Error.  Otherwise, Assign clears Target and then
+   --  copies the (active) elements from Source to Target.
+
+   function Copy
+     (Source   : Map;
+      Capacity : Count_Type := 0;
+      Modulus  : Hash_Type := 0) return Map;
+   --  Constructs a new set object whose elements correspond to Source.  If the
+   --  Capacity parameter is 0, then the capacity of the result is the same as
+   --  the length of Source. If the Capacity parameter is equal or greater than
+   --  the length of Source, then the capacity of the result is the specified
+   --  value. Otherwise, Copy raises Capacity_Error. If the Modulus parameter
+   --  is 0, then the modulus of the result is the value returned by a call to
+   --  Default_Modulus with the capacity parameter determined as above;
+   --  otherwise the modulus of the result is the specified value.
+
+   procedure Move (Target : in out Map; Source : in out Map);
+   --  Clears Target (if it's not empty), and then moves (not copies) the
+   --  buckets array and nodes from Source to Target.
+
+   procedure Insert
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type;
+      Position  : out Cursor;
+      Inserted  : out Boolean);
+   --  Conditionally inserts New_Item into the map. If Key is already in the
+   --  map, then Inserted returns False and Position designates the node
+   --  containing the existing key/element pair (neither of which is modified).
+   --  If Key is not already in the map, the Inserted returns True and Position
+   --  designates the newly-inserted node container Key and New_Item. The
+   --  search for the key works as follows. Hash is called to determine Key's
+   --  bucket; if the bucket is non-empty, then Equivalent_Keys is called to
+   --  compare Key to each node in that bucket. If the bucket is empty, or
+   --  there were no matching keys in the bucket, the search "fails" and the
+   --  key/item pair is inserted in the map (and Inserted returns True);
+   --  otherwise, the search "succeeds" (and Inserted returns False).
+
+   procedure Insert
+     (Container : in out Map;
+      Key       : Key_Type;
+      Position  : out Cursor;
+      Inserted  : out Boolean);
+   --  The same as the (conditional) Insert that accepts an element parameter,
+   --  with the difference that if Inserted returns True, then the element of
+   --  the newly-inserted node is initialized to its default value.
+
+   procedure Insert
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type);
+   --  Attempts to insert Key into the map, performing the usual search (which
+   --  involves calling both Hash and Equivalent_Keys); if the search succeeds
+   --  (because Key is already in the map), then it raises Constraint_Error.
+   --  (This version of Insert is similar to Replace, but having the opposite
+   --  exception behavior. It is intended for use when you want to assert that
+   --  Key is not already in the map.)
+
+   procedure Include
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type);
+   --  Attempts to insert Key into the map. If Key is already in the map, then
+   --  both the existing key and element are assigned the values of Key and
+   --  New_Item, respectively. (This version of Insert only raises an exception
+   --  if cursor tampering occurs. It is intended for use when you want to
+   --  insert the key/element pair in the map, and you don't care whether Key
+   --  is already present.)
+
+   procedure Replace
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type);
+   --  Searches for Key in the map; if the search fails (because Key was not in
+   --  the map), then it raises Constraint_Error. Otherwise, both the existing
+   --  key and element are assigned the values of Key and New_Item rsp. (This
+   --  is similar to Insert, but with the opposite exception behavior. It is to
+   --  be used when you want to assert that Key is already in the map.)
+
+   procedure Exclude (Container : in out Map; Key : Key_Type);
+   --  Searches for Key in the map, and if found, removes its node from the map
+   --  and then deallocates it. The search works as follows. The operation
+   --  calls Hash to determine the key's bucket; if the bucket is not empty, it
+   --  calls Equivalent_Keys to compare Key to each key in the bucket. (This is
+   --  the deletion analog of Include. It is intended for use when you want to
+   --  remove the item from the map, but don't care whether the key is already
+   --  in the map.)
+
+   procedure Delete (Container : in out Map; Key : Key_Type);
+   --  Searches for Key in the map (which involves calling both Hash and
+   --  Equivalent_Keys). If the search fails, then the operation raises
+   --  Constraint_Error. Otherwise it removes the node from the map and then
+   --  deallocates it. (This is the deletion analog of non-conditional
+   --  Insert. It is intended for use when you want to assert that the item is
+   --  already in the map.)
+
+   procedure Delete (Container : in out Map; Position : in out Cursor);
+   --  Removes the node designated by Position from the map, and then
+   --  deallocates the node. The operation calls Hash to determine the bucket,
+   --  and then compares Position to each node in the bucket until there's a
+   --  match (it does not call Equivalent_Keys).
+
+   function First (Container : Map) return Cursor;
+   --  Returns a cursor that designates the first non-empty bucket, by
+   --  searching from the beginning of the buckets array.
+
+   function Next (Position : Cursor) return Cursor;
+   --  Returns a cursor that designates the node that follows the current one
+   --  designated by Position. If Position designates the last node in its
+   --  bucket, the operation calls Hash to compute the index of this bucket,
+   --  and searches the buckets array for the first non-empty bucket, starting
+   --  from that index; otherwise, it simply follows the link to the next node
+   --  in the same bucket.
+
+   procedure Next (Position : in out Cursor);
+   --  Equivalent to Position := Next (Position)
+
+   function Find (Container : Map; Key : Key_Type) return Cursor;
+   --  Searches for Key in the map. Find calls Hash to determine the key's
+   --  bucket; if the bucket is not empty, it calls Equivalent_Keys to compare
+   --  Key to each key in the bucket. If the search succeeds, Find returns a
+   --  cursor designating the matching node; otherwise, it returns No_Element.
+
+   function Contains (Container : Map; Key : Key_Type) return Boolean;
+   --  Equivalent to Find (Container, Key) /= No_Element
+
+   function Element (Container : Map; Key : Key_Type) return Element_Type;
+   --  Equivalent to Element (Find (Container, Key))
+
+   function Has_Element (Position : Cursor) return Boolean;
+   --  Equivalent to Position /= No_Element
+
+   function Equivalent_Keys (Left, Right : Cursor) return Boolean;
+   --  Returns the result of calling Equivalent_Keys with the keys of the nodes
+   --  designated by cursors Left and Right.
+
+   function Equivalent_Keys (Left : Cursor; Right : Key_Type) return Boolean;
+   --  Returns the result of calling Equivalent_Keys with key of the node
+   --  designated by Left and key Right.
+
+   function Equivalent_Keys (Left : Key_Type; Right : Cursor) return Boolean;
+   --  Returns the result of calling Equivalent_Keys with key Left and the node
+   --  designated by Right.
+
+   procedure Iterate
+     (Container : Map;
+      Process   : not null access procedure (Position : Cursor));
+   --  Calls Process for each node in the map
+
+private
+   --  pragma Inline ("=");
+   pragma Inline (Length);
+   pragma Inline (Is_Empty);
+   pragma Inline (Clear);
+   pragma Inline (Key);
+   pragma Inline (Element);
+   pragma Inline (Move);
+   pragma Inline (Contains);
+   pragma Inline (Capacity);
+   pragma Inline (Reserve_Capacity);
+   pragma Inline (Has_Element);
+   pragma Inline (Equivalent_Keys);
+   pragma Inline (Next);
+
+   type Node_Type is record
+      Key     : Key_Type;
+      Element : Element_Type;
+      Next    : Count_Type;
+   end record;
+
+   package HT_Types is
+     new Hash_Tables.Generic_Bounded_Hash_Table_Types (Node_Type);
+
+   type Map (Capacity : Count_Type; Modulus : Hash_Type) is
+      new HT_Types.Hash_Table_Type (Capacity, Modulus) with null record;
+
+   use HT_Types;
+   use Ada.Streams;
+
+   procedure Write
+     (Stream    : not null access Root_Stream_Type'Class;
+      Container : Map);
+
+   for Map'Write use Write;
+
+   procedure Read
+     (Stream    : not null access Root_Stream_Type'Class;
+      Container : out Map);
+
+   for Map'Read use Read;
+
+   type Map_Access is access all Map;
+   for Map_Access'Storage_Size use 0;
+
+   type Cursor is record
+      Container : Map_Access;
+      Node      : Count_Type;
+   end record;
+
+   procedure Read
+     (Stream : not null access Root_Stream_Type'Class;
+      Item   : out Cursor);
+
+   for Cursor'Read use Read;
+
+   procedure Write
+     (Stream : not null access Root_Stream_Type'Class;
+      Item   : Cursor);
+
+   for Cursor'Write use Write;
+
+   No_Element : constant Cursor := (Container => null, Node => 0);
+
+   Empty_Map : constant Map :=
+     (Hash_Table_Type with Capacity => 0, Modulus => 0);
+
+end Ada.Containers.Bounded_Hashed_Maps;
Index: Makefile.rtl
===================================================================
--- Makefile.rtl	(revision 165938)
+++ Makefile.rtl	(working copy)
@@ -86,6 +86,8 @@  GNATRTL_NONTASKING_OBJS= \
   a-calend$(objext) \
   a-calfor$(objext) \
   a-catizo$(objext) \
+  a-cbhama$(objext) \
+  a-cbhase$(objext) \
   a-cborse$(objext) \
   a-cbdlli$(objext) \
   a-cborma$(objext) \
@@ -98,6 +100,8 @@  GNATRTL_NONTASKING_OBJS= \
   a-charac$(objext) \
   a-chlat1$(objext) \
   a-chlat9$(objext) \
+  a-chtgbo$(objext) \
+  a-chtgbk$(objext) \
   a-chtgke$(objext) \
   a-chtgop$(objext) \
   a-chzla1$(objext) \
Index: a-chtgbk.adb
===================================================================
--- a-chtgbk.adb	(revision 0)
+++ a-chtgbk.adb	(revision 0)
@@ -0,0 +1,322 @@ 
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT LIBRARY COMPONENTS                          --
+--                                                                          --
+--              ADA.CONTAINERS.HASH_TABLES.GENERIC_BOUNDED_KEYS             --
+--                                                                          --
+--                                 B o d y                                  --
+--                                                                          --
+--          Copyright (C) 2004-2010, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+package body Ada.Containers.Hash_Tables.Generic_Bounded_Keys is
+
+   --------------------------
+   -- Delete_Key_Sans_Free --
+   --------------------------
+
+   procedure Delete_Key_Sans_Free
+     (HT  : in out Hash_Table_Type'Class;
+      Key : Key_Type;
+      X   : out Count_Type)
+   is
+      Indx : Hash_Type;
+      Prev : Count_Type;
+
+   begin
+      if HT.Length = 0 then
+         X := 0;
+         return;
+      end if;
+
+      Indx := Index (HT, Key);
+      X := HT.Buckets (Indx);
+
+      if X = 0 then
+         return;
+      end if;
+
+      if Equivalent_Keys (Key, HT.Nodes (X)) then
+         if HT.Busy > 0 then
+            raise Program_Error with
+              "attempt to tamper with cursors (container is busy)";
+         end if;
+         HT.Buckets (Indx) := Next (HT.Nodes (X));
+         HT.Length := HT.Length - 1;
+         return;
+      end if;
+
+      loop
+         Prev := X;
+         X := Next (HT.Nodes (Prev));
+
+         if X = 0 then
+            return;
+         end if;
+
+         if Equivalent_Keys (Key, HT.Nodes (X)) then
+            if HT.Busy > 0 then
+               raise Program_Error with
+                 "attempt to tamper with cursors (container is busy)";
+            end if;
+            Set_Next (HT.Nodes (Prev), Next => Next (HT.Nodes (X)));
+            HT.Length := HT.Length - 1;
+            return;
+         end if;
+      end loop;
+   end Delete_Key_Sans_Free;
+
+   ----------
+   -- Find --
+   ----------
+
+   function Find
+     (HT  : Hash_Table_Type'Class;
+      Key : Key_Type) return Count_Type
+   is
+      Indx : Hash_Type;
+      Node : Count_Type;
+
+   begin
+      if HT.Length = 0 then
+         return 0;
+      end if;
+
+      Indx := Index (HT, Key);
+
+      Node := HT.Buckets (Indx);
+      while Node /= 0 loop
+         if Equivalent_Keys (Key, HT.Nodes (Node)) then
+            return Node;
+         end if;
+         Node := Next (HT.Nodes (Node));
+      end loop;
+
+      return 0;
+   end Find;
+
+   --------------------------------
+   -- Generic_Conditional_Insert --
+   --------------------------------
+
+   procedure Generic_Conditional_Insert
+     (HT       : in out Hash_Table_Type'Class;
+      Key      : Key_Type;
+      Node     : out Count_Type;
+      Inserted : out Boolean)
+   is
+      Indx : constant Hash_Type := Index (HT, Key);
+      B    : Count_Type renames HT.Buckets (Indx);
+
+   begin
+      if B = 0 then
+         if HT.Busy > 0 then
+            raise Program_Error with
+              "attempt to tamper with cursors (container is busy)";
+         end if;
+
+         if HT.Length = HT.Capacity then
+            raise Capacity_Error with "no more capacity for insertion";
+         end if;
+
+         Node := New_Node;
+         Set_Next (HT.Nodes (Node), Next => 0);
+
+         Inserted := True;
+
+         B := Node;
+         HT.Length := HT.Length + 1;
+
+         return;
+      end if;
+
+      Node := B;
+      loop
+         if Equivalent_Keys (Key, HT.Nodes (Node)) then
+            Inserted := False;
+            return;
+         end if;
+
+         Node := Next (HT.Nodes (Node));
+
+         exit when Node = 0;
+      end loop;
+
+      if HT.Busy > 0 then
+         raise Program_Error with
+           "attempt to tamper with cursors (container is busy)";
+      end if;
+
+      if HT.Length = HT.Capacity then
+         raise Capacity_Error with "no more capacity for insertion";
+      end if;
+
+      Node := New_Node;
+      Set_Next (HT.Nodes (Node), Next => B);
+
+      Inserted := True;
+
+      B := Node;
+      HT.Length := HT.Length + 1;
+   end Generic_Conditional_Insert;
+
+   -----------
+   -- Index --
+   -----------
+
+   function Index
+     (HT  : Hash_Table_Type'Class;
+      Key : Key_Type) return Hash_Type is
+   begin
+      return HT.Buckets'First + Hash (Key) mod HT.Buckets'Length;
+   end Index;
+
+   -----------------------------
+   -- Generic_Replace_Element --
+   -----------------------------
+
+   procedure Generic_Replace_Element
+     (HT   : in out Hash_Table_Type'Class;
+      Node : Count_Type;
+      Key  : Key_Type)
+   is
+      pragma Assert (HT.Length > 0);
+      pragma Assert (Node /= 0);
+
+      BB : Buckets_Type renames HT.Buckets;
+      NN : Nodes_Type renames HT.Nodes;
+
+      Old_Hash : constant Hash_Type := Hash (NN (Node));
+      Old_Indx : constant Hash_Type := BB'First + Old_Hash mod BB'Length;
+
+      New_Hash : constant Hash_Type := Hash (Key);
+      New_Indx : constant Hash_Type := BB'First + New_Hash mod BB'Length;
+
+      New_Bucket : Count_Type renames BB (New_Indx);
+      N, M       : Count_Type;
+
+   begin
+      --  Replace_Element is allowed to change a node's key to Key
+      --  (generic formal operation Assign provides the mechanism), but
+      --  only if Key is not already in the hash table. (In a unique-key
+      --  hash table as this one, a key is mapped to exactly one node.)
+
+      if Equivalent_Keys (Key, NN (Node)) then
+         pragma Assert (New_Hash = Old_Hash);
+
+         if HT.Lock > 0 then
+            raise Program_Error with
+              "attempt to tamper with elements (container is locked)";
+         end if;
+
+         --  The new Key value is mapped to this same Node, so Node
+         --  stays in the same bucket.
+
+         Assign (NN (Node), Key);
+         pragma Assert (Hash (NN (Node)) = New_Hash);
+         pragma Assert (Equivalent_Keys (Key, NN (Node)));
+         return;
+      end if;
+
+      --  Key is not equivalent to Node, so we now have to determine if it's
+      --  equivalent to some other node in the hash table. This is the case
+      --  irrespective of whether Key is in the same or a different bucket from
+      --  Node.
+
+      N := New_Bucket;
+      while N /= 0 loop
+         if Equivalent_Keys (Key, NN (N)) then
+            pragma Assert (N /= Node);
+            raise Program_Error with
+              "attempt to replace existing element";
+         end if;
+
+         N := Next (NN (N));
+      end loop;
+
+      --  We have determined that Key is not already in the hash table, so
+      --  the change is tentatively allowed. We now perform the standard
+      --  checks to determine whether the hash table is locked (because you
+      --  cannot change an element while it's in use by Query_Element or
+      --  Update_Element), or if the container is busy (because moving a
+      --  node to a different bucket would interfere with iteration).
+
+      if Old_Indx = New_Indx then
+         --  The node is already in the bucket implied by Key. In this case
+         --  we merely change its value without moving it.
+
+         if HT.Lock > 0 then
+            raise Program_Error with
+              "attempt to tamper with elements (container is locked)";
+         end if;
+
+         Assign (NN (Node), Key);
+         pragma Assert (Hash (NN (Node)) = New_Hash);
+         pragma Assert (Equivalent_Keys (Key, NN (Node)));
+         return;
+      end if;
+
+      --  The node is a bucket different from the bucket implied by Key
+
+      if HT.Busy > 0 then
+         raise Program_Error with
+           "attempt to tamper with cursors (container is busy)";
+      end if;
+
+      --  Do the assignment first, before moving the node, so that if Assign
+      --  propagates an exception, then the hash table will not have been
+      --  modified (except for any possible side-effect Assign had on Node).
+
+      Assign (NN (Node), Key);
+      pragma Assert (Hash (NN (Node)) = New_Hash);
+      pragma Assert (Equivalent_Keys (Key, NN (Node)));
+
+      --  Now we can safely remove the node from its current bucket
+
+      N := BB (Old_Indx);  -- get value of first node in old bucket
+      pragma Assert (N /= 0);
+
+      if N = Node then  -- node is first node in its bucket
+         BB (Old_Indx) := Next (NN (Node));
+
+      else
+         pragma Assert (HT.Length > 1);
+
+         loop
+            M := Next (NN (N));
+            pragma Assert (M /= 0);
+
+            if M = Node then
+               Set_Next (NN (N), Next => Next (NN (Node)));
+               exit;
+            end if;
+
+            N := M;
+         end loop;
+      end if;
+
+      --  Now we link the node into its new bucket (corresponding to Key)
+
+      Set_Next (NN (Node), Next => New_Bucket);
+      New_Bucket := Node;
+   end Generic_Replace_Element;
+
+end Ada.Containers.Hash_Tables.Generic_Bounded_Keys;
Index: a-chtgbk.ads
===================================================================
--- a-chtgbk.ads	(revision 0)
+++ a-chtgbk.ads	(revision 0)
@@ -0,0 +1,106 @@ 
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT LIBRARY COMPONENTS                          --
+--                                                                          --
+--              ADA.CONTAINERS.HASH_TABLES.GENERIC_BOUNDED_KEYS             --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2004-2010, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+--  Hash_Table_Type is used to implement hashed containers. This package
+--  declares hash-table operations that depend on keys.
+
+generic
+   with package HT_Types is
+     new Generic_Bounded_Hash_Table_Types (<>);
+
+   use HT_Types;
+
+   with function Next (Node : Node_Type) return Count_Type;
+
+   with procedure Set_Next
+     (Node : in out Node_Type;
+      Next : Count_Type);
+
+   type Key_Type (<>) is limited private;
+
+   with function Hash (Key : Key_Type) return Hash_Type;
+
+   with function Equivalent_Keys
+     (Key  : Key_Type;
+      Node : Node_Type) return Boolean;
+
+package Ada.Containers.Hash_Tables.Generic_Bounded_Keys is
+   pragma Pure;
+
+   function Index
+     (HT  : Hash_Table_Type'Class;
+      Key : Key_Type) return Hash_Type;
+   pragma Inline (Index);
+   --  Returns the bucket number (array index value) for the given key
+
+   procedure Delete_Key_Sans_Free
+     (HT  : in out Hash_Table_Type'Class;
+      Key : Key_Type;
+      X   : out Count_Type);
+   --  Removes the node (if any) with the given key from the hash table,
+   --  without deallocating it. Program_Error is raised if the hash
+   --  table is busy.
+
+   function Find
+     (HT  : Hash_Table_Type'Class;
+      Key : Key_Type) return Count_Type;
+   --  Returns the node (if any) corresponding to the given key
+
+   generic
+      with function New_Node return Count_Type;
+   procedure Generic_Conditional_Insert
+     (HT       : in out Hash_Table_Type'Class;
+      Key      : Key_Type;
+      Node     : out Count_Type;
+      Inserted : out Boolean);
+   --  Attempts to insert a new node with the given key into the hash table.
+   --  If a node with that key already exists in the table, then that node
+   --  is returned and Inserted returns False. Otherwise New_Node is called
+   --  to allocate a new node, and Inserted returns True. Program_Error is
+   --  raised if the hash table is busy.
+
+   generic
+      with function Hash (Node : Node_Type) return Hash_Type;
+      with procedure Assign (Node : in out Node_Type; Key : Key_Type);
+   procedure Generic_Replace_Element
+     (HT   : in out Hash_Table_Type'Class;
+      Node : Count_Type;
+      Key  : Key_Type);
+   --  Assigns Key to Node, possibly changing its equivalence class. If Node
+   --  is in the same equivalence class as Key (that is, it's already in the
+   --  bucket implied by Key), then if the hash table is locked then
+   --  Program_Error is raised; otherwise Assign is called to assign Key to
+   --  Node. If Node is in a different bucket from Key, then Program_Error is
+   --  raised if the hash table is busy. Otherwise it Assigns Key to Node and
+   --  moves the Node from its current bucket to the bucket implied by Key.
+   --  Note that it is never proper to assign to Node a key value already
+   --  in the map, and so if Key is equivalent to some other node then
+   --  Program_Error is raised.
+
+end Ada.Containers.Hash_Tables.Generic_Bounded_Keys;
Index: a-chtgbo.adb
===================================================================
--- a-chtgbo.adb	(revision 0)
+++ a-chtgbo.adb	(revision 0)
@@ -0,0 +1,473 @@ 
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT LIBRARY COMPONENTS                          --
+--                                                                          --
+--           ADA.CONTAINERS.HASH_TABLES.GENERIC_BOUNDED_OPERATIONS          --
+--                                                                          --
+--                                 B o d y                                  --
+--                                                                          --
+--          Copyright (C) 2004-2010, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+with System;  use type System.Address;
+
+package body Ada.Containers.Hash_Tables.Generic_Bounded_Operations is
+
+   -----------
+   -- Clear --
+   -----------
+
+   procedure Clear (HT : in out Hash_Table_Type'Class) is
+   begin
+      if HT.Busy > 0 then
+         raise Program_Error with
+           "attempt to tamper with cursors (container is busy)";
+      end if;
+
+      HT.Length := 0;
+      --  HT.Busy := 0;
+      --  HT.Lock := 0;
+      HT.Free := -1;
+      HT.Buckets := (others => 0);  -- optimize this somehow ???
+   end Clear;
+
+   ---------------------------
+   -- Delete_Node_Sans_Free --
+   ---------------------------
+
+   procedure Delete_Node_Sans_Free
+     (HT : in out Hash_Table_Type'Class;
+      X  : Count_Type)
+   is
+      pragma Assert (X /= 0);
+
+      Indx : Hash_Type;
+      Prev : Count_Type;
+      Curr : Count_Type;
+
+   begin
+      if HT.Length = 0 then
+         raise Program_Error with
+           "attempt to delete node from empty hashed container";
+      end if;
+
+      Indx := Index (HT, HT.Nodes (X));
+      Prev := HT.Buckets (Indx);
+
+      if Prev = 0 then
+         raise Program_Error with
+           "attempt to delete node from empty hash bucket";
+      end if;
+
+      if Prev = X then
+         HT.Buckets (Indx) := Next (HT, Prev);
+         HT.Length := HT.Length - 1;
+         return;
+      end if;
+
+      if HT.Length = 1 then
+         raise Program_Error with
+           "attempt to delete node not in its proper hash bucket";
+      end if;
+
+      loop
+         Curr := Next (HT, Prev);
+
+         if Curr = 0 then
+            raise Program_Error with
+              "attempt to delete node not in its proper hash bucket";
+         end if;
+
+         if Curr = X then
+            Set_Next (HT.Nodes (Prev), Next => Next (HT, Curr));
+            HT.Length := HT.Length - 1;
+            return;
+         end if;
+
+         Prev := Curr;
+      end loop;
+   end Delete_Node_Sans_Free;
+
+   -----------
+   -- First --
+   -----------
+
+   function First (HT : Hash_Table_Type'Class) return Count_Type is
+      Indx : Hash_Type;
+
+   begin
+      if HT.Length = 0 then
+         return 0;
+      end if;
+
+      Indx := HT.Buckets'First;
+      loop
+         if HT.Buckets (Indx) /= 0 then
+            return HT.Buckets (Indx);
+         end if;
+
+         Indx := Indx + 1;
+      end loop;
+   end First;
+
+   ----------
+   -- Free --
+   ----------
+
+   procedure Free
+     (HT : in out Hash_Table_Type'Class;
+      X  : Count_Type)
+   is
+      pragma Assert (X > 0);
+      pragma Assert (X <= HT.Capacity);
+
+      N : Nodes_Type renames HT.Nodes;
+      --  pragma Assert (N (X).Prev >= 0);  -- node is active
+      --  Find a way to mark a node as active vs. inactive; we could
+      --  use a special value in Color_Type for this.  ???
+
+   begin
+      --  The hash table actually contains two data structures: a list for
+      --  the "active" nodes that contain elements that have been inserted
+      --  onto the container, and another for the "inactive" nodes of the free
+      --  store.
+      --
+      --  We desire that merely declaring an object should have only minimal
+      --  cost; specially, we want to avoid having to initialize the free
+      --  store (to fill in the links), especially if the capacity is large.
+      --
+      --  The head of the free list is indicated by Container.Free. If its
+      --  value is non-negative, then the free store has been initialized
+      --  in the "normal" way: Container.Free points to the head of the list
+      --  of free (inactive) nodes, and the value 0 means the free list is
+      --  empty. Each node on the free list has been initialized to point
+      --  to the next free node (via its Parent component), and the value 0
+      --  means that this is the last free node.
+      --
+      --  If Container.Free is negative, then the links on the free store
+      --  have not been initialized. In this case the link values are
+      --  implied: the free store comprises the components of the node array
+      --  started with the absolute value of Container.Free, and continuing
+      --  until the end of the array (Nodes'Last).
+      --
+      --  ???
+      --  It might be possible to perform an optimization here. Suppose that
+      --  the free store can be represented as having two parts: one
+      --  comprising the non-contiguous inactive nodes linked together
+      --  in the normal way, and the other comprising the contiguous
+      --  inactive nodes (that are not linked together, at the end of the
+      --  nodes array). This would allow us to never have to initialize
+      --  the free store, except in a lazy way as nodes become inactive.
+
+      --  When an element is deleted from the list container, its node
+      --  becomes inactive, and so we set its Next component to value of
+      --  the node's index (in the nodes array), to indicate that it is
+      --  now inactive. This provides a useful way to detect a dangling
+      --  cursor reference.  ???
+
+      Set_Next (N (X), Next => X);  -- Node is deallocated (not on active list)
+
+      if HT.Free >= 0 then
+         --  The free store has previously been initialized. All we need to
+         --  do here is link the newly-free'd node onto the free list.
+
+         Set_Next (N (X), HT.Free);
+         HT.Free := X;
+
+      elsif X + 1 = abs HT.Free then
+         --  The free store has not been initialized, and the node becoming
+         --  inactive immediately precedes the start of the free store. All
+         --  we need to do is move the start of the free store back by one.
+
+         HT.Free := HT.Free + 1;
+
+      else
+         --  The free store has not been initialized, and the node becoming
+         --  inactive does not immediately precede the free store. Here we
+         --  first initialize the free store (meaning the links are given
+         --  values in the traditional way), and then link the newly-free'd
+         --  node onto the head of the free store.
+
+         --  ???
+         --  See the comments above for an optimization opportunity. If
+         --  the next link for a node on the free store is negative, then
+         --  this means the remaining nodes on the free store are
+         --  physically contiguous, starting as the absolute value of
+         --  that index value.
+
+         HT.Free := abs HT.Free;
+
+         if HT.Free > HT.Capacity then
+            HT.Free := 0;
+
+         else
+            for I in HT.Free .. HT.Capacity - 1 loop
+               Set_Next (Node => N (I), Next => I + 1);
+            end loop;
+
+            Set_Next (Node => N (HT.Capacity), Next => 0);
+         end if;
+
+         Set_Next (Node => N (X), Next => HT.Free);
+         HT.Free := X;
+      end if;
+   end Free;
+
+   ----------------------
+   -- Generic_Allocate --
+   ----------------------
+
+   procedure Generic_Allocate
+     (HT   : in out Hash_Table_Type'Class;
+      Node : out Count_Type)
+   is
+      N : Nodes_Type renames HT.Nodes;
+
+   begin
+      if HT.Free >= 0 then
+         Node := HT.Free;
+
+         --  We always perform the assignment first, before we
+         --  change container state, in order to defend against
+         --  exceptions duration assignment.
+
+         Set_Element (N (Node));
+         HT.Free := Next (N (Node));
+
+      else
+         --  A negative free store value means that the links of the nodes
+         --  in the free store have not been initialized. In this case, the
+         --  nodes are physically contiguous in the array, starting at the
+         --  index that is the absolute value of the Container.Free, and
+         --  continuing until the end of the array (Nodes'Last).
+
+         Node := abs HT.Free;
+
+         --  As above, we perform this assignment first, before modifying
+         --  any container state.
+
+         Set_Element (N (Node));
+         HT.Free := HT.Free - 1;
+      end if;
+   end Generic_Allocate;
+
+   -------------------
+   -- Generic_Equal --
+   -------------------
+
+   function Generic_Equal
+     (L, R : Hash_Table_Type'Class) return Boolean
+   is
+      L_Index : Hash_Type;
+      L_Node  : Count_Type;
+
+      N : Count_Type;
+
+   begin
+      if L'Address = R'Address then
+         return True;
+      end if;
+
+      if L.Length /= R.Length then
+         return False;
+      end if;
+
+      if L.Length = 0 then
+         return True;
+      end if;
+
+      --  Find the first node of hash table L
+
+      L_Index := 0;
+      loop
+         L_Node := L.Buckets (L_Index);
+         exit when L_Node /= 0;
+         L_Index := L_Index + 1;
+      end loop;
+
+      --  For each node of hash table L, search for an equivalent node in hash
+      --  table R.
+
+      N := L.Length;
+      loop
+         if not Find (HT => R, Key => L.Nodes (L_Node)) then
+            return False;
+         end if;
+
+         N := N - 1;
+
+         L_Node := Next (L, L_Node);
+
+         if L_Node = 0 then
+            --  We have exhausted the nodes in this bucket
+
+            if N = 0 then
+               return True;
+            end if;
+
+            --  Find the next bucket
+
+            loop
+               L_Index := L_Index + 1;
+               L_Node := L.Buckets (L_Index);
+               exit when L_Node /= 0;
+            end loop;
+         end if;
+      end loop;
+   end Generic_Equal;
+
+   -----------------------
+   -- Generic_Iteration --
+   -----------------------
+
+   procedure Generic_Iteration (HT : Hash_Table_Type'Class) is
+      Node : Count_Type;
+
+   begin
+      if HT.Length = 0 then
+         return;
+      end if;
+
+      for Indx in HT.Buckets'Range loop
+         Node := HT.Buckets (Indx);
+         while Node /= 0 loop
+            Process (Node);
+            Node := Next (HT, Node);
+         end loop;
+      end loop;
+   end Generic_Iteration;
+
+   ------------------
+   -- Generic_Read --
+   ------------------
+
+   procedure Generic_Read
+     (Stream : not null access Root_Stream_Type'Class;
+      HT     : out Hash_Table_Type'Class)
+   is
+      N  : Count_Type'Base;
+
+   begin
+      Clear (HT);
+
+      Count_Type'Base'Read (Stream, N);
+
+      if N < 0 then
+         raise Program_Error with "stream appears to be corrupt";
+      end if;
+
+      if N = 0 then
+         return;
+      end if;
+
+      if N > HT.Capacity then
+         raise Capacity_Error with "too many elements in stream";
+      end if;
+
+      for J in 1 .. N loop
+         declare
+            Node : constant Count_Type := New_Node (Stream);
+            Indx : constant Hash_Type := Index (HT, HT.Nodes (Node));
+            B    : Count_Type renames HT.Buckets (Indx);
+         begin
+            Set_Next (HT.Nodes (Node), Next => B);
+            B := Node;
+         end;
+
+         HT.Length := HT.Length + 1;
+      end loop;
+   end Generic_Read;
+
+   -------------------
+   -- Generic_Write --
+   -------------------
+
+   procedure Generic_Write
+     (Stream : not null access Root_Stream_Type'Class;
+      HT     : Hash_Table_Type'Class)
+   is
+      procedure Write (Node : Count_Type);
+      pragma Inline (Write);
+
+      procedure Write is new Generic_Iteration (Write);
+
+      -----------
+      -- Write --
+      -----------
+
+      procedure Write (Node : Count_Type) is
+      begin
+         Write (Stream, HT.Nodes (Node));
+      end Write;
+
+   begin
+      Count_Type'Base'Write (Stream, HT.Length);
+      Write (HT);
+   end Generic_Write;
+
+   -----------
+   -- Index --
+   -----------
+
+   function Index
+     (Buckets : Buckets_Type;
+      Node    : Node_Type) return Hash_Type is
+   begin
+      return Buckets'First + Hash_Node (Node) mod Buckets'Length;
+   end Index;
+
+   function Index
+     (HT   : Hash_Table_Type'Class;
+      Node : Node_Type) return Hash_Type is
+   begin
+      return Index (HT.Buckets, Node);
+   end Index;
+
+   ----------
+   -- Next --
+   ----------
+
+   function Next
+     (HT   : Hash_Table_Type'Class;
+      Node : Count_Type) return Count_Type
+   is
+      Result : Count_Type := Next (HT.Nodes (Node));
+
+   begin
+      if Result /= 0 then  -- another node in same bucket
+         return Result;
+      end if;
+
+      --  This was the last node in the bucket, so move to the next
+      --  bucket, and start searching for next node from there.
+
+      for Indx in Index (HT, HT.Nodes (Node)) + 1 .. HT.Buckets'Last loop
+         Result := HT.Buckets (Indx);
+
+         if Result /= 0 then  -- bucket is not empty
+            return Result;
+         end if;
+      end loop;
+
+      return 0;
+   end Next;
+
+end Ada.Containers.Hash_Tables.Generic_Bounded_Operations;
Index: a-chtgbo.ads
===================================================================
--- a-chtgbo.ads	(revision 0)
+++ a-chtgbo.ads	(revision 0)
@@ -0,0 +1,140 @@ 
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT LIBRARY COMPONENTS                          --
+--                                                                          --
+--           ADA.CONTAINERS.HASH_TABLES.GENERIC_BOUNDED_OPERATIONS          --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2004-2010, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+--  Hash_Table_Type is used to implement hashed containers. This package
+--  declares hash-table operations that do not depend on keys.
+
+with Ada.Streams;
+
+generic
+   with package HT_Types is
+     new Generic_Bounded_Hash_Table_Types (<>);
+
+   use HT_Types;
+
+   with function Hash_Node (Node : Node_Type) return Hash_Type;
+
+   with function Next (Node : Node_Type) return Count_Type;
+
+   with procedure Set_Next
+     (Node : in out Node_Type;
+      Next : Count_Type);
+
+package Ada.Containers.Hash_Tables.Generic_Bounded_Operations is
+   pragma Pure;
+
+   function Index
+     (Buckets : Buckets_Type;
+      Node    : Node_Type) return Hash_Type;
+   pragma Inline (Index);
+   --  Uses the hash value of Node to compute its Buckets array index
+
+   function Index
+     (HT   : Hash_Table_Type'Class;
+      Node : Node_Type) return Hash_Type;
+   pragma Inline (Index);
+   --  Uses the hash value of Node to compute its Hash_Table buckets array
+   --  index.
+
+   generic
+      with function Find
+        (HT  : Hash_Table_Type'Class;
+         Key : Node_Type) return Boolean;
+   function Generic_Equal (L, R : Hash_Table_Type'Class) return Boolean;
+   --  Used to implement hashed container equality. For each node in hash table
+   --  L, it calls Find to search for an equivalent item in hash table R. If
+   --  Find returns False for any node then Generic_Equal terminates
+   --  immediately and returns False. Otherwise if Find returns True for every
+   --  node then Generic_Equal returns True.
+
+   procedure Clear (HT : in out Hash_Table_Type'Class);
+   --  Deallocates each node in hash table HT. (Note that it only deallocates
+   --  the nodes, not the buckets array.)  Program_Error is raised if the hash
+   --  table is busy.
+
+   procedure Delete_Node_Sans_Free
+     (HT : in out Hash_Table_Type'Class;
+      X  : Count_Type);
+   --  Removes node X from the hash table without deallocating the node
+
+   generic
+      with procedure Set_Element (Node : in out Node_Type);
+   procedure Generic_Allocate
+     (HT   : in out Hash_Table_Type'Class;
+      Node : out Count_Type);
+   --  Claim a node from the free store. Generic_Allocate first
+   --  calls Set_Element on the potential node, and then returns
+   --  the node's index as the value of the Node parameter.
+
+   procedure Free
+     (HT : in out Hash_Table_Type'Class;
+      X  : Count_Type);
+   --  Return a node back to the free store, from where it had
+   --  been previously claimed via Generic_Allocate.
+
+   function First (HT : Hash_Table_Type'Class) return Count_Type;
+   --  Returns the head of the list in the first (lowest-index) non-empty
+   --  bucket.
+
+   function Next
+     (HT   : Hash_Table_Type'Class;
+      Node : Count_Type) return Count_Type;
+   --  Returns the node that immediately follows Node. This corresponds to
+   --  either the next node in the same bucket, or (if Node is the last node in
+   --  its bucket) the head of the list in the first non-empty bucket that
+   --  follows.
+
+   generic
+      with procedure Process (Node : Count_Type);
+   procedure Generic_Iteration (HT : Hash_Table_Type'Class);
+   --  Calls Process for each node in hash table HT
+
+   generic
+      use Ada.Streams;
+      with procedure Write
+        (Stream : not null access Root_Stream_Type'Class;
+         Node   : Node_Type);
+   procedure Generic_Write
+     (Stream : not null access Root_Stream_Type'Class;
+      HT     : Hash_Table_Type'Class);
+   --  Used to implement the streaming attribute for hashed containers. It
+   --  calls Write for each node to write its value into Stream.
+
+   generic
+      use Ada.Streams;
+      with function New_Node (Stream : not null access Root_Stream_Type'Class)
+         return Count_Type;
+   procedure Generic_Read
+     (Stream : not null access Root_Stream_Type'Class;
+      HT     : out Hash_Table_Type'Class);
+   --  Used to implement the streaming attribute for hashed containers. It
+   --  first clears hash table HT, then populates the hash table by calling
+   --  New_Node for each item in Stream.
+
+end Ada.Containers.Hash_Tables.Generic_Bounded_Operations;
Index: a-cbhase.adb
===================================================================
--- a-cbhase.adb	(revision 0)
+++ a-cbhase.adb	(revision 0)
@@ -0,0 +1,1737 @@ 
+------------------------------------------------------------------------------
+--                                                                          --
+--                         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) 2004-2010, Free Software Foundation, Inc.         --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+with 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;
+
+   --------------
+   -- 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;
+
+      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 (Source, 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 := 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_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");
+
+      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;
+
+   ----------
+   -- 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 Cursor'(Container'Unrestricted_Access, 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 Cursor'(Container'Unrestricted_Access, Node);
+   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
+      --  ???
+      --  if HT_Ops.Capacity (HT) = 0 then
+      --     HT_Ops.Reserve_Capacity (HT, 1);
+      --  end if;
+
+      Local_Insert (Container, New_Item, Node, Inserted);
+
+      --  ???
+      --  if Inserted
+      --    and then HT.Length > HT_Ops.Capacity (HT)
+      --  then
+      --     HT_Ops.Reserve_Capacity (HT, HT.Length);
+      --  end if;
+   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, 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, 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.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;
+
+   ------------
+   -- 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;
+
+      Assign (Target => Target, Source => Source);
+   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;
+
+   -------------
+   -- 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, 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;
+
+   -------------
+   -- 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 Left.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;
+
+      --  ???
+      --  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.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;
+
+   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);
+
+      --------------
+      -- 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, Key);
+
+      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);
+         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, Key);
+
+      begin
+         if Node = 0 then
+            return No_Element;
+         end if;
+
+         return 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;
+
+      -------------
+      -- 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;
+
+         --  ???
+         --  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");
+
+         --  Record bucket now, in case key is changed.
+         Indx := HT_Ops.Index (Container.Buckets, N (Position.Node));
+
+         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;
+
+         begin
+            B := B + 1;
+            L := L + 1;
+
+            begin
+               Process (E);
+            exception
+               when others =>
+                  L := L - 1;
+                  B := B - 1;
+                  raise;
+            end;
+
+            L := L - 1;
+            B := B - 1;
+
+            if Equivalent_Keys (K, Key (E)) then
+               pragma Assert (Hash (K) = Hash (E));
+               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;
+
+   end Generic_Keys;
+
+end Ada.Containers.Bounded_Hashed_Sets;
Index: a-cbhase.ads
===================================================================
--- a-cbhase.ads	(revision 0)
+++ a-cbhase.ads	(revision 0)
@@ -0,0 +1,466 @@ 
+------------------------------------------------------------------------------
+--                                                                          --
+--                         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   --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2004-2010, 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    --
+-- <http://www.gnu.org/licenses/>.                                          --
+--                                                                          --
+-- This unit was originally developed by Matthew J Heaney.                  --
+------------------------------------------------------------------------------
+
+private with Ada.Containers.Hash_Tables;
+private with Ada.Streams;
+
+generic
+   type Element_Type is private;
+
+   with function Hash (Element : Element_Type) return Hash_Type;
+
+   with function Equivalent_Elements
+          (Left, Right : Element_Type) return Boolean;
+
+   with function "=" (Left, Right : Element_Type) return Boolean is <>;
+
+package Ada.Containers.Bounded_Hashed_Sets is
+   pragma Pure;
+   pragma Remote_Types;
+
+   type Set (Capacity : Count_Type; Modulus : Hash_Type) is tagged private;
+   pragma Preelaborable_Initialization (Set);
+
+   type Cursor is private;
+   pragma Preelaborable_Initialization (Cursor);
+
+   Empty_Set : constant Set;
+   --  Set objects declared without an initialization expression are
+   --  initialized to the value Empty_Set.
+
+   No_Element : constant Cursor;
+   --  Cursor objects declared without an initialization expression are
+   --  initialized to the value No_Element.
+
+   function "=" (Left, Right : Set) return Boolean;
+   --  For each element in Left, set equality attempts to find the equal
+   --  element in Right; if a search fails, then set equality immediately
+   --  returns False. The search works by calling Hash to find the bucket in
+   --  the Right set that corresponds to the Left element. If the bucket is
+   --  non-empty, the search calls the generic formal element equality operator
+   --  to compare the element (in Left) to the element of each node in the
+   --  bucket (in Right); the search terminates when a matching node in the
+   --  bucket is found, or the nodes in the bucket are exhausted. (Note that
+   --  element equality is called here, not Equivalent_Elements. Set equality
+   --  is the only operation in which element equality is used. Compare set
+   --  equality to Equivalent_Sets, which does call Equivalent_Elements.)
+
+   function Equivalent_Sets (Left, Right : Set) return Boolean;
+   --  Similar to set equality, with the difference that the element in Left is
+   --  compared to the elements in Right using the generic formal
+   --  Equivalent_Elements operation instead of element equality.
+
+   function To_Set (New_Item : Element_Type) return Set;
+   --  Constructs a singleton set comprising New_Element. To_Set calls Hash to
+   --  determine the bucket for New_Item.
+
+   function Capacity (Container : Set) return Count_Type;
+   --  Returns the current capacity of the set. Capacity is the maximum length
+   --  before which rehashing in guaranteed not to occur.
+
+   procedure Reserve_Capacity (Container : in out Set; Capacity : Count_Type);
+   --  If the value of the Capacity actual parameter is less or equal to
+   --  Container.Capacity, then the operation has no effect.  Otherwise it
+   --  raises Capacity_Error (as no expansion of capacity is possible for a
+   --  bounded form).
+
+   function Default_Modulus (Capacity : Count_Type) return Hash_Type;
+   --  Returns a modulus value (hash table size) which is optimal for the
+   --  specified capacity (which corresponds to the maximum number of items).
+
+   function Length (Container : Set) return Count_Type;
+   --  Returns the number of items in the set
+
+   function Is_Empty (Container : Set) return Boolean;
+   --  Equivalent to Length (Container) = 0
+
+   procedure Clear (Container : in out Set);
+   --  Removes all of the items from the set
+
+   function Element (Position : Cursor) return Element_Type;
+   --  Returns the element of the node designated by the cursor
+
+   procedure Replace_Element
+     (Container : in out Set;
+      Position  : Cursor;
+      New_Item  : Element_Type);
+   --  If New_Item is equivalent (as determined by calling Equivalent_Elements)
+   --  to the element of the node designated by Position, then New_Element is
+   --  assigned to that element. Otherwise, it calls Hash to determine the
+   --  bucket for New_Item. If the bucket is not empty, then it calls
+   --  Equivalent_Elements for each node in that bucket to determine whether
+   --  New_Item is equivalent to an element in that bucket. If
+   --  Equivalent_Elements returns True then Program_Error is raised (because
+   --  an element may appear only once in the set); otherwise, New_Item is
+   --  assigned to the node designated by Position, and the node is moved to
+   --  its new bucket.
+
+   procedure Query_Element
+     (Position : Cursor;
+      Process  : not null access procedure (Element : Element_Type));
+   --  Calls Process with the element (having only a constant view) of the node
+   --  designed by the cursor.
+
+   procedure Assign (Target : in out Set; Source : Set);
+   --  If Target denotes the same object as Source, then the operation has no
+   --  effect. If the Target capacity is less then the Source length, then
+   --  Assign raises Capacity_Error.  Otherwise, Assign clears Target and then
+   --  copies the (active) elements from Source to Target.
+
+   function Copy
+     (Source   : Set;
+      Capacity : Count_Type := 0;
+      Modulus  : Hash_Type := 0) return Set;
+   --  Constructs a new set object whose elements correspond to Source.  If the
+   --  Capacity parameter is 0, then the capacity of the result is the same as
+   --  the length of Source. If the Capacity parameter is equal or greater than
+   --  the length of Source, then the capacity of the result is the specified
+   --  value. Otherwise, Copy raises Capacity_Error. If the Modulus parameter
+   --  is 0, then the modulus of the result is the value returned by a call to
+   --  Default_Modulus with the capacity parameter determined as above;
+   --  otherwise the modulus of the result is the specified value.
+
+   procedure Move (Target : in out Set; Source : in out Set);
+   --  Clears Target (if it's not empty), and then moves (not copies) the
+   --  buckets array and nodes from Source to Target.
+
+   procedure Insert
+     (Container : in out Set;
+      New_Item  : Element_Type;
+      Position  : out Cursor;
+      Inserted  : out Boolean);
+   --  Conditionally inserts New_Item into the set. If New_Item is already in
+   --  the set, then Inserted returns False and Position designates the node
+   --  containing the existing element (which is not modified). If New_Item is
+   --  not already in the set, then Inserted returns True and Position
+   --  designates the newly-inserted node containing New_Item. The search for
+   --  an existing element works as follows. Hash is called to determine
+   --  New_Item's bucket; if the bucket is non-empty, then Equivalent_Elements
+   --  is called to compare New_Item to the element of each node in that
+   --  bucket. If the bucket is empty, or there were no equivalent elements in
+   --  the bucket, the search "fails" and the New_Item is inserted in the set
+   --  (and Inserted returns True); otherwise, the search "succeeds" (and
+   --  Inserted returns False).
+
+   procedure Insert  (Container : in out Set; New_Item : Element_Type);
+   --  Attempts to insert New_Item into the set, performing the usual insertion
+   --  search (which involves calling both Hash and Equivalent_Elements); if
+   --  the search succeeds (New_Item is equivalent to an element already in the
+   --  set, and so was not inserted), then this operation raises
+   --  Constraint_Error. (This version of Insert is similar to Replace, but
+   --  having the opposite exception behavior. It is intended for use when you
+   --  want to assert that the item is not already in the set.)
+
+   procedure Include (Container : in out Set; New_Item : Element_Type);
+   --  Attempts to insert New_Item into the set. If an element equivalent to
+   --  New_Item is already in the set (the insertion search succeeded, and
+   --  hence New_Item was not inserted), then the value of New_Item is assigned
+   --  to the existing element. (This insertion operation only raises an
+   --  exception if cursor tampering occurs. It is intended for use when you
+   --  want to insert the item in the set, and you don't care whether an
+   --  equivalent element is already present.)
+
+   procedure Replace (Container : in out Set; New_Item : Element_Type);
+   --  Searches for New_Item in the set; if the search fails (because an
+   --  equivalent element was not in the set), then it raises
+   --  Constraint_Error. Otherwise, the existing element is assigned the value
+   --  New_Item. (This is similar to Insert, but with the opposite exception
+   --  behavior. It is intended for use when you want to assert that the item
+   --  is already in the set.)
+
+   procedure Exclude (Container : in out Set; Item : Element_Type);
+   --  Searches for Item in the set, and if found, removes its node from the
+   --  set and then deallocates it. The search works as follows. The operation
+   --  calls Hash to determine the item's bucket; if the bucket is not empty,
+   --  it calls Equivalent_Elements to compare Item to the element of each node
+   --  in the bucket. (This is the deletion analog of Include. It is intended
+   --  for use when you want to remove the item from the set, but don't care
+   --  whether the item is already in the set.)
+
+   procedure Delete  (Container : in out Set; Item : Element_Type);
+   --  Searches for Item in the set (which involves calling both Hash and
+   --  Equivalent_Elements). If the search fails, then the operation raises
+   --  Constraint_Error. Otherwise it removes the node from the set and then
+   --  deallocates it. (This is the deletion analog of non-conditional
+   --  Insert. It is intended for use when you want to assert that the item is
+   --  already in the set.)
+
+   procedure Delete (Container : in out Set; Position : in out Cursor);
+   --  Removes the node designated by Position from the set, and then
+   --  deallocates the node. The operation calls Hash to determine the bucket,
+   --  and then compares Position to each node in the bucket until there's a
+   --  match (it does not call Equivalent_Elements).
+
+   procedure Union (Target : in out Set; Source : Set);
+   --  Iterates over the Source set, and conditionally inserts each element
+   --  into Target.
+
+   function Union (Left, Right : Set) return Set;
+   --  The operation first copies the Left set to the result, and then iterates
+   --  over the Right set to conditionally insert each element into the result.
+
+   function "or" (Left, Right : Set) return Set renames Union;
+
+   procedure Intersection (Target : in out Set; Source : Set);
+   --  Iterates over the Target set (calling First and Next), calling Find to
+   --  determine whether the element is in Source. If an equivalent element is
+   --  not found in Source, the element is deleted from Target.
+
+   function Intersection (Left, Right : Set) return Set;
+   --  Iterates over the Left set, calling Find to determine whether the
+   --  element is in Right. If an equivalent element is found, it is inserted
+   --  into the result set.
+
+   function "and" (Left, Right : Set) return Set renames Intersection;
+
+   procedure Difference (Target : in out Set; Source : Set);
+   --  Iterates over the Source (calling First and Next), calling Find to
+   --  determine whether the element is in Target. If an equivalent element is
+   --  found, it is deleted from Target.
+
+   function Difference (Left, Right : Set) return Set;
+   --  Iterates over the Left set, calling Find to determine whether the
+   --  element is in the Right set. If an equivalent element is not found, the
+   --  element is inserted into the result set.
+
+   function "-" (Left, Right : Set) return Set renames Difference;
+
+   procedure Symmetric_Difference (Target : in out Set; Source : Set);
+   --  The operation iterates over the Source set, searching for the element
+   --  in Target (calling Hash and Equivalent_Elements). If an equivalent
+   --  elementis found, it is removed from Target; otherwise it is inserted
+   --  into Target.
+
+   function Symmetric_Difference (Left, Right : Set) return Set;
+   --  The operation first iterates over the Left set. It calls Find to
+   --  determine whether the element is in the Right set. If no equivalent
+   --  element is found, the element from Left is inserted into the result. The
+   --  operation then iterates over the Right set, to determine whether the
+   --  element is in the Left set. If no equivalent element is found, the Right
+   --  element is inserted into the result.
+
+   function "xor" (Left, Right : Set) return Set
+     renames Symmetric_Difference;
+
+   function Overlap (Left, Right : Set) return Boolean;
+   --  Iterates over the Left set (calling First and Next), calling Find to
+   --  determine whether the element is in the Right set. If an equivalent
+   --  element is found, the operation immediately returns True. The operation
+   --  returns False if the iteration over Left terminates without finding any
+   --  equivalent element in Right.
+
+   function Is_Subset (Subset : Set; Of_Set : Set) return Boolean;
+   --  Iterates over Subset (calling First and Next), calling Find to determine
+   --  whether the element is in Of_Set. If no equivalent element is found in
+   --  Of_Set, the operation immediately returns False. The operation returns
+   --  True if the iteration over Subset terminates without finding an element
+   --  not in Of_Set (that is, every element in Subset is equivalent to an
+   --  element in Of_Set).
+
+   function First (Container : Set) return Cursor;
+   --  Returns a cursor that designates the first non-empty bucket, by
+   --  searching from the beginning of the buckets array.
+
+   function Next (Position : Cursor) return Cursor;
+   --  Returns a cursor that designates the node that follows the current one
+   --  designated by Position. If Position designates the last node in its
+   --  bucket, the operation calls Hash to compute the index of this bucket,
+   --  and searches the buckets array for the first non-empty bucket, starting
+   --  from that index; otherwise, it simply follows the link to the next node
+   --  in the same bucket.
+
+   procedure Next (Position : in out Cursor);
+   --  Equivalent to Position := Next (Position)
+
+   function Find
+     (Container : Set;
+      Item      : Element_Type) return Cursor;
+   --  Searches for Item in the set. Find calls Hash to determine the item's
+   --  bucket; if the bucket is not empty, it calls Equivalent_Elements to
+   --  compare Item to each element in the bucket. If the search succeeds, Find
+   --  returns a cursor designating the node containing the equivalent element;
+   --  otherwise, it returns No_Element.
+
+   function Contains (Container : Set; Item : Element_Type) return Boolean;
+   --  Equivalent to Find (Container, Item) /= No_Element
+
+   function Has_Element (Position : Cursor) return Boolean;
+   --  Equivalent to Position /= No_Element
+
+   function Equivalent_Elements (Left, Right : Cursor) return Boolean;
+   --  Returns the result of calling Equivalent_Elements with the elements of
+   --  the nodes designated by cursors Left and Right.
+
+   function Equivalent_Elements
+     (Left  : Cursor;
+      Right : Element_Type) return Boolean;
+   --  Returns the result of calling Equivalent_Elements with element of the
+   --  node designated by Left and element Right.
+
+   function Equivalent_Elements
+     (Left  : Element_Type;
+      Right : Cursor) return Boolean;
+   --  Returns the result of calling Equivalent_Elements with element Left and
+   --  the element of the node designated by Right.
+
+   procedure Iterate
+     (Container : Set;
+      Process   : not null access procedure (Position : Cursor));
+   --  Calls Process for each node in the set
+
+   generic
+      type Key_Type (<>) is private;
+
+      with function Key (Element : Element_Type) return Key_Type;
+
+      with function Hash (Key : Key_Type) return Hash_Type;
+
+      with function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
+
+   package Generic_Keys is
+
+      function Key (Position : Cursor) return Key_Type;
+      --  Applies generic formal operation Key to the element of the node
+      --  designated by Position.
+
+      function Element (Container : Set; Key : Key_Type) return Element_Type;
+      --  Searches (as per the key-based Find) for the node containing Key, and
+      --  returns the associated element.
+
+      procedure Replace
+        (Container : in out Set;
+         Key       : Key_Type;
+         New_Item  : Element_Type);
+      --  Searches (as per the key-based Find) for the node containing Key, and
+      --  then replaces the element of that node (as per the element-based
+      --  Replace_Element).
+
+      procedure Exclude (Container : in out Set; Key : Key_Type);
+      --  Searches for Key in the set, and if found, removes its node from the
+      --  set and then deallocates it. The search works by first calling Hash
+      --  (on Key) to determine the bucket; if the bucket is not empty, it
+      --  calls Equivalent_Keys to compare parameter Key to the value of
+      --  generic formal operation Key applied to element of each node in the
+      --  bucket.
+
+      procedure Delete (Container : in out Set; Key : Key_Type);
+      --  Deletes the node containing Key as per Exclude, with the difference
+      --  that Constraint_Error is raised if Key is not found.
+
+      function Find (Container : Set; Key : Key_Type) return Cursor;
+      --  Searches for the node containing Key, and returns a cursor
+      --  designating the node. The search works by first calling Hash (on Key)
+      --  to determine the bucket. If the bucket is not empty, the search
+      --  compares Key to the element of each node in the bucket, and returns
+      --  the matching node. The comparison itself works by applying the
+      --  generic formal Key operation to the element of the node, and then
+      --  calling generic formal operation Equivalent_Keys.
+
+      function Contains (Container : Set; Key : Key_Type) return Boolean;
+      --  Equivalent to Find (Container, Key) /= No_Element
+
+      procedure Update_Element_Preserving_Key
+        (Container : in out Set;
+         Position  : Cursor;
+         Process   : not null access
+                       procedure (Element : in out Element_Type));
+      --  Calls Process with the element of the node designated by Position,
+      --  but with the restriction that the key-value of the element is not
+      --  modified. The operation first makes a copy of the value returned by
+      --  applying generic formal operation Key on the element of the node, and
+      --  then calls Process with the element. The operation verifies that the
+      --  key-part has not been modified by calling generic formal operation
+      --  Equivalent_Keys to compare the saved key-value to the value returned
+      --  by applying generic formal operation Key to the post-Process value of
+      --  element. If the key values compare equal then the operation
+      --  completes. Otherwise, the node is removed from the map and
+      --  Program_Error is raised.
+
+   end Generic_Keys;
+
+private
+
+   pragma Inline (Next);
+
+   type Node_Type is record
+      Element : Element_Type;
+      Next    : Count_Type;
+   end record;
+
+   package HT_Types is
+     new Hash_Tables.Generic_Bounded_Hash_Table_Types (Node_Type);
+
+   type Set (Capacity : Count_Type; Modulus : Hash_Type) is
+      new HT_Types.Hash_Table_Type (Capacity, Modulus) with null record;
+
+   use HT_Types;
+   use Ada.Streams;
+
+   type Set_Access is access all Set;
+   for Set_Access'Storage_Size use 0;
+
+   type Cursor is record
+      Container : Set_Access;
+      Node      : Count_Type;
+   end record;
+
+   procedure Write
+     (Stream : not null access Root_Stream_Type'Class;
+      Item   : Cursor);
+
+   for Cursor'Write use Write;
+
+   procedure Read
+     (Stream : not null access Root_Stream_Type'Class;
+      Item   : out Cursor);
+
+   for Cursor'Read use Read;
+
+   No_Element : constant Cursor := (Container => null, Node => 0);
+
+   procedure Write
+     (Stream    : not null access Root_Stream_Type'Class;
+      Container : Set);
+
+   for Set'Write use Write;
+
+   procedure Read
+     (Stream    : not null access Root_Stream_Type'Class;
+      Container : out Set);
+
+   for Set'Read use Read;
+
+   Empty_Set : constant Set :=
+     (Hash_Table_Type with Capacity => 0, Modulus => 0);
+
+end Ada.Containers.Bounded_Hashed_Sets;