File : bc-containers-sets.ads
-- Copyright (C) 1994-1999 Grady Booch and Simon Wright.
-- All Rights Reserved.
--
-- This program is free software; you can redistribute it
-- and/or modify it under the terms of the Ada Community
-- License which comes with this Library.
--
-- This program is distributed in the hope that it will be
-- useful, but WITHOUT ANY WARRANTY; without even the implied
-- warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
-- PURPOSE. See the Ada Community License for more details.
-- You should have received a copy of the Ada Community
-- License with this library, in the file named "Ada Community
-- License" or "ACL". If not, contact the author of this library
-- for a copy.
--
-- $Id: bc-containers-sets.ads,v 1.2.2.2 1999/12/31 15:10:40 simon Exp $
generic
package BC.Containers.Sets is
pragma Elaborate_Body;
-- A set denotes a collection of items, drawn from some well-defined
-- universe. A set may not contain duplicate items.
-- The parameter Item denotes the universe from which the set draws its
-- items. Items may be a primitive type or user-defined.
type Set is abstract new Container with private;
function Are_Equal (L, R : Set'Class) return Boolean;
-- Return True if and only if both sets have the same number of distinct
-- items, and the same items themselves; return False otherwise.
-- Can't call this "=" because of the standard one for Set.
procedure Clear (S : in out Set) is abstract;
-- Empty the set of all items.
procedure Add (S : in out Set; I : Item; Added : out Boolean) is abstract;
-- Add the item to the set. If the item is not already a distinct member
-- of the set, copy the item and add it to the set and set Added to
-- True. If the item already exists, then set Added to False.
procedure Add (S : in out Set'Class; I : Item);
-- Add the item to the set. If the item is not already a distinct member
-- of the set, copy the item and add it to the set.
procedure Remove (S : in out Set; I : Item) is abstract;
-- If the item is not a member of the set, raise BC.Not_Found. Otherwise,
-- remove the item from the set.
procedure Union (S : in out Set'Class; O : Set'Class);
-- Perform a logical set union; at the completion of this operation, the
-- set S contains the items found in its original state combined with the
-- set O (but without duplication). For each item in the set O, if the
-- item is not already a distinct member of the set S, copy the item and
-- add it to the set S. If the item already is a member, do nothing.
procedure Intersection (S : in out Set'Class; O : Set'Class);
-- Perform a logical set intersection; at the completion of this
-- operation, the set S contains the items found both in its original
-- state and in the set O. For each item in the set O, if the item is not
-- already a distinct member of the set S, do nothing. If the item
-- already is a member of S, do nothing. Items in the set S but not in
-- the set O are also removed.
procedure Difference (S : in out Set'Class; O : Set'Class);
-- Perform a logical set difference; at the completion of this operation,
-- the set S contains the items found in its original state, less those
-- found in the set O. For each item in the set O, if the item is not
-- already a distinct member of the set S, do nothing. If the item
-- is a member, remove the item from the set S.
function Extent (S : Set) return Natural is abstract;
-- Return the number of distinct items in the set.
function Is_Empty (S : Set) return Boolean is abstract;
-- Return True if and only if there are no items in the set.
function Is_Member (S : Set; I : Item) return Boolean is abstract;
-- Return True if and only if the item exists in the set.
function Is_Subset (S : Set'Class; O : Set'Class) return Boolean;
-- Return True if and only if all the items in the set S are also in the
-- set O.
function Is_Proper_Subset (S : Set'Class; O : Set'Class) return Boolean;
-- Return True if and only if all the items in the set S are also in the
-- set O, and there is at least one item in O that is not in S.
private
type Set is abstract new Container with null record;
procedure Attach (S : in out Set; I : Item);
procedure Detach (S : in out Set; I : Item);
function Number_Of_Buckets (S : Set) return Natural;
function Length (S : Set; Bucket : Positive) return Natural;
function Exists (S : Set; I : Item) return Boolean;
function Item_At (S : Set; Bucket, Index : Positive) return Item_Ptr;
type Set_Iterator (S : access Set'Class)
is new Actual_Iterator (S) with record
Bucket_Index : Natural := 0;
Index : Natural := 0;
end record;
procedure Initialize (It : in out Set_Iterator);
-- Overriding primitive supbrograms of the concrete actual Iterator.
procedure Reset (It : in out Set_Iterator);
procedure Next (It : in out Set_Iterator);
function Is_Done (It : Set_Iterator) return Boolean;
function Current_Item (It : Set_Iterator) return Item;
function Current_Item (It : Set_Iterator) return Item_Ptr;
procedure Delete_Item_At (It : Set_Iterator);
end BC.Containers.Sets;