-- --
-- S p e c --
-- --
--- Copyright (C) 2004 Free Software Foundation, Inc. --
+-- Copyright (C) 2004-2011, 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 --
-- --
-- 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 2, or (at your option) any later ver- --
+-- 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. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING. If not, write --
--- to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, --
--- MA 02111-1307, USA. --
+-- or FITNESS FOR A PARTICULAR PURPOSE. --
-- --
--- As a special exception, if other files instantiate generics from this --
--- unit, or you link this unit with other files to produce an executable, --
--- this unit does not by itself cause the resulting executable to be --
--- covered by the GNU General Public License. This exception does not --
--- however invalidate any other reasons why the executable file might be --
--- covered by the GNU Public License. --
+-- 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;
-with Ada.Streams;
+with Ada.Iterator_Interfaces;
+private with Ada.Containers.Hash_Tables;
+private with Ada.Streams;
+private with Ada.Finalization;
generic
type Element_Type (<>) is private;
with function Hash (Element : Element_Type) return Hash_Type;
- -- TODO: get a ruling from ARG in Atlanta re the name and
- -- order of these declarations ???
-
- with function Equivalent_Keys (Left, Right : Element_Type) return Boolean;
+ with function Equivalent_Elements (Left, Right : Element_Type)
+ return Boolean;
with function "=" (Left, Right : Element_Type) return Boolean is <>;
package Ada.Containers.Indefinite_Hashed_Sets is
+ pragma Preelaborate;
+ pragma Remote_Types;
- pragma Preelaborate (Indefinite_Hashed_Sets);
+ type Set is tagged private
+ with Constant_Indexing => Constant_Reference,
+ Default_Iterator => Iterate,
+ Iterator_Element => Element_Type;
- type Set 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 Has_Element (Position : Cursor) return Boolean;
+ -- Equivalent to Position /= No_Element
+
+ package Set_Iterator_Interfaces is new
+ Ada.Iterator_Interfaces (Cursor, Has_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);
+ -- Adjusts the current capacity, by allocating a new buckets array. If the
+ -- requested capacity is less than the current capacity, then the capacity
+ -- is contracted (to a value not less than the current length). If the
+ -- requested capacity is greater than the current capacity, then the
+ -- capacity is expanded (to a value not less than what is requested). In
+ -- either case, the nodes are rehashed from the old buckets array onto the
+ -- new buckets array (Hash is called once for each existing element in
+ -- order to compute the new index), and then the old buckets array is
+ -- deallocated.
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
+ -- designated by the cursor.
+
+ type Constant_Reference_Type
+ (Element : not null access constant Element_Type) is private
+ with Implicit_Dereference => Element;
+
+ function Constant_Reference
+ (Container : aliased Set;
+ Position : Cursor)
+ return Constant_Reference_Type;
+
+ procedure Assign (Target : in out Set; Source : Set);
--- TODO: resolve in atlanta ???
--- procedure Replace_Element (Container : in out Set;
--- Position : Cursor;
--- By : Element_Type);
+ function Copy (Source : Set; Capacity : Count_Type := 0) return Set;
- procedure Move
- (Target : in out Set;
- Source : in out Set);
+ 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);
-
- procedure Delete (Container : in out Set; 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);
+ -- The operation first calls Reserve_Capacity if the current capacity is
+ -- less than the sum of the lengths of Source and Target. It then 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 first calls Reserve_Capacity if the current capacity is
+ -- less than the sum of the lengths of Source and Target. It then iterates
+ -- over the Source set, searching for the element in Target (calling Hash
+ -- and Equivalent_Elements). If an equivalent element is 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 Is_Subset (Subset : Set; Of_Set : Set) return Boolean;
-
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 Contains (Container : Set; Item : Element_Type) return Boolean;
-
- function Find (Container : Set; Item : Element_Type) return Cursor;
-
- function Capacity (Container : Set) return Count_Type;
-
- procedure Reserve_Capacity
- (Container : in out Set;
- Capacity : Count_Type);
+ 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 Has_Element (Position : Cursor) return Boolean;
+ 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 Equivalent_Keys (Left, Right : Cursor) return Boolean;
+ function Contains (Container : Set; Item : Element_Type) return Boolean;
+ -- Equivalent to Find (Container, Item) /= 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_Keys
+ 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_Keys
+ 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
+
+ function Iterate (Container : Set)
+ return Set_Iterator_Interfaces.Forward_Iterator'Class;
generic
- type Key_Type (<>) is limited private;
+ 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
- (Key : Key_Type;
- Element : Element_Type) return Boolean;
+ with function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
package Generic_Keys is
- function Contains (Container : Set; Key : Key_Type) return Boolean;
-
- function Find (Container : Set; Key : Key_Type) return Cursor;
-
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).
--- TODO: resolve in atlanta???
--- procedure Replace (Container : in out Set;
--- Key : Key_Type;
--- New_Item : Element_Type);
+ 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.
- procedure Exclude (Container : in out Set; Key : Key_Type);
+ 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.
- procedure Checked_Update_Element
+ 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));
-
- function Equivalent_Keys
- (Left : Cursor;
- Right : Key_Type) return Boolean;
-
- function Equivalent_Keys
- (Left : Key_Type;
- Right : Cursor) return Boolean;
+ -- 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.
+
+ type Reference_Type (Element : not null access Element_Type) is private
+ with Implicit_Dereference => Element;
+
+ function Reference_Preserving_Key
+ (Container : aliased in out Set;
+ Position : Cursor) return Reference_Type;
+
+ function Reference_Preserving_Key
+ (Container : aliased in out Set;
+ Key : Key_Type) return Reference_Type;
+
+ private
+ type Reference_Type (Element : not null access Element_Type)
+ is null record;
end Generic_Keys;
private
+ pragma Inline (Next);
+
type Node_Type;
type Node_Access is access Node_Type;
+ type Element_Access is access Element_Type;
+
+ type Node_Type is limited record
+ Element : Element_Access;
+ Next : Node_Access;
+ end record;
+
package HT_Types is
- new Hash_Tables.Generic_Hash_Table_Types (Node_Access);
+ new Hash_Tables.Generic_Hash_Table_Types (Node_Type, Node_Access);
- use HT_Types;
+ type Set is new Ada.Finalization.Controlled with record
+ HT : HT_Types.Hash_Table_Type;
+ end record;
- type Set is new Hash_Table_Type with null record;
+ overriding procedure Adjust (Container : in out Set);
- procedure Adjust (Container : in out Set);
+ overriding procedure Finalize (Container : in out Set);
- procedure Finalize (Container : in out Set);
+ use HT_Types;
+ use Ada.Finalization;
+ use Ada.Streams;
- type Set_Access is access constant Set;
+ type Set_Access is access all Set;
for Set_Access'Storage_Size use 0;
- type Cursor is
- record
- Container : Set_Access;
- Node : Node_Access;
- end record;
+ type Cursor is record
+ Container : Set_Access;
+ Node : Node_Access;
+ end record;
- No_Element : constant Cursor :=
- (Container => null,
- Node => null);
+ procedure Write
+ (Stream : not null access Root_Stream_Type'Class;
+ Item : Cursor);
- use Ada.Streams;
+ 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 => null);
procedure Write
- (Stream : access Root_Stream_Type'Class;
+ (Stream : not null access Root_Stream_Type'Class;
Container : Set);
for Set'Write use Write;
procedure Read
- (Stream : access Root_Stream_Type'Class;
+ (Stream : not null access Root_Stream_Type'Class;
Container : out Set);
for Set'Read use Read;
- Empty_Set : constant Set := (Hash_Table_Type with null record);
+ type Constant_Reference_Type
+ (Element : not null access constant Element_Type) is null record;
-end Ada.Containers.Indefinite_Hashed_Sets;
+ procedure Read
+ (Stream : not null access Root_Stream_Type'Class;
+ Item : out Constant_Reference_Type);
+
+ for Constant_Reference_Type'Read use Read;
+
+ procedure Write
+ (Stream : not null access Root_Stream_Type'Class;
+ Item : Constant_Reference_Type);
+
+ for Constant_Reference_Type'Write use Write;
+ Empty_Set : constant Set := (Controlled with HT => (null, 0, 0, 0));
+
+end Ada.Containers.Indefinite_Hashed_Sets;
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