571 lines
24 KiB
Ada
571 lines
24 KiB
Ada
------------------------------------------------------------------------------
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-- --
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-- GNAT LIBRARY COMPONENTS --
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-- --
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-- A D A . C O N T A I N E R S . O R D E R E D _ M U L T I S E T S --
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-- --
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-- S p e c --
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-- --
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-- Copyright (C) 2004-2015, Free Software Foundation, Inc. --
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-- --
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-- GNAT is free software; you can redistribute it and/or modify it under --
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-- terms of the GNU General Public License as published by the Free Soft- --
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-- ware Foundation; either version 3, or (at your option) any later ver- --
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-- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
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-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
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-- or FITNESS FOR A PARTICULAR PURPOSE. --
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-- --
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-- As a special exception under Section 7 of GPL version 3, you are granted --
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-- additional permissions described in the GCC Runtime Library Exception, --
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-- version 3.1, as published by the Free Software Foundation. --
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-- --
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-- You should have received a copy of the GNU General Public License and --
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-- a copy of the GCC Runtime Library Exception along with this program; --
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-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
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-- <http://www.gnu.org/licenses/>. --
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-- --
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-- This unit was originally developed by Matthew J Heaney. --
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------------------------------------------------------------------------------
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-- The ordered multiset container is similar to the ordered set, but with the
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-- difference that multiple equivalent elements are allowed. It also provides
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-- additional operations, to iterate over items that are equivalent.
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private with Ada.Containers.Red_Black_Trees;
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private with Ada.Finalization;
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private with Ada.Streams;
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with Ada.Iterator_Interfaces;
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generic
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type Element_Type is private;
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with function "<" (Left, Right : Element_Type) return Boolean is <>;
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with function "=" (Left, Right : Element_Type) return Boolean is <>;
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package Ada.Containers.Ordered_Multisets is
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pragma Annotate (CodePeer, Skip_Analysis);
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pragma Preelaborate;
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pragma Remote_Types;
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function Equivalent_Elements (Left, Right : Element_Type) return Boolean;
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-- Returns False if Left is less than Right, or Right is less than Left;
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-- otherwise, it returns True.
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type Set is tagged private
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with Constant_Indexing => Constant_Reference,
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Default_Iterator => Iterate,
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Iterator_Element => Element_Type;
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pragma Preelaborable_Initialization (Set);
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type Cursor is private;
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pragma Preelaborable_Initialization (Cursor);
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Empty_Set : constant Set;
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-- The default value for set objects declared without an explicit
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-- initialization expression.
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No_Element : constant Cursor;
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-- The default value for cursor objects declared without an explicit
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-- initialization expression.
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function Has_Element (Position : Cursor) return Boolean;
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-- Equivalent to Position /= No_Element
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package Set_Iterator_Interfaces is new
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Ada.Iterator_Interfaces (Cursor, Has_Element);
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function "=" (Left, Right : Set) return Boolean;
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-- If Left denotes the same set object as Right, then equality returns
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-- True. If the length of Left is different from the length of Right, then
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-- it returns False. Otherwise, set equality iterates over Left and Right,
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-- comparing the element of Left to the element of Right using the equality
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-- operator for elements. If the elements compare False, then the iteration
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-- terminates and set equality returns False. Otherwise, if all elements
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-- compare True, then set equality returns True.
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function Equivalent_Sets (Left, Right : Set) return Boolean;
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-- Similar to set equality, but with the difference that elements are
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-- compared for equivalence instead of equality.
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function To_Set (New_Item : Element_Type) return Set;
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-- Constructs a set object with New_Item as its single element
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function Length (Container : Set) return Count_Type;
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-- Returns the total number of elements in Container
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function Is_Empty (Container : Set) return Boolean;
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-- Returns True if Container.Length is 0
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procedure Clear (Container : in out Set);
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-- Deletes all elements from Container
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function Element (Position : Cursor) return Element_Type;
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-- If Position equals No_Element, then Constraint_Error is raised.
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-- Otherwise, function Element returns the element designed by Position.
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procedure Replace_Element
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(Container : in out Set;
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Position : Cursor;
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New_Item : Element_Type);
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-- If Position equals No_Element, then Constraint_Error is raised. If
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-- Position is associated with a set different from Container, then
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-- Program_Error is raised. If New_Item is equivalent to the element
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-- designated by Position, then if Container is locked (element tampering
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-- has been attempted), Program_Error is raised; otherwise, the element
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-- designated by Position is assigned the value of New_Item. If New_Item is
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-- not equivalent to the element designated by Position, then if the
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-- container is busy (cursor tampering has been attempted), Program_Error
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-- is raised; otherwise, the element designed by Position is assigned the
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-- value of New_Item, and the node is moved to its new position (in
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-- canonical insertion order).
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procedure Query_Element
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(Position : Cursor;
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Process : not null access procedure (Element : Element_Type));
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-- If Position equals No_Element, then Constraint_Error is
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-- raised. Otherwise, it calls Process with the element designated by
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-- Position as the parameter. This call locks the container, so attempts to
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-- change the value of the element while Process is executing (to "tamper
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-- with elements") will raise Program_Error.
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type Constant_Reference_Type
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(Element : not null access constant Element_Type) is private
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with Implicit_Dereference => Element;
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function Constant_Reference
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(Container : aliased Set;
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Position : Cursor) return Constant_Reference_Type;
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pragma Inline (Constant_Reference);
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procedure Assign (Target : in out Set; Source : Set);
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function Copy (Source : Set) return Set;
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procedure Move (Target : in out Set; Source : in out Set);
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-- If Target denotes the same object as Source, the operation does
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-- nothing. If either Target or Source is busy (cursor tampering is
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-- attempted), then it raises Program_Error. Otherwise, Target is cleared,
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-- and the nodes from Source are moved (not copied) to Target (so Source
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-- becomes empty).
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procedure Insert
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(Container : in out Set;
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New_Item : Element_Type;
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Position : out Cursor);
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-- Insert adds New_Item to Container, and returns cursor Position
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-- designating the newly inserted node. The node is inserted after any
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-- existing elements less than or equivalent to New_Item (and before any
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-- elements greater than New_Item). Note that the issue of where the new
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-- node is inserted relative to equivalent elements does not arise for
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-- unique-key containers, since in that case the insertion would simply
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-- fail. For a multiple-key container (the case here), insertion always
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-- succeeds, and is defined such that the new item is positioned after any
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-- equivalent elements already in the container.
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procedure Insert
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(Container : in out Set;
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New_Item : Element_Type);
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-- Inserts New_Item in Container, but does not return a cursor designating
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-- the newly-inserted node.
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-- TODO: include Replace too???
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--
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-- procedure Replace
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-- (Container : in out Set;
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-- New_Item : Element_Type);
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procedure Exclude
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(Container : in out Set;
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Item : Element_Type);
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-- Deletes from Container all of the elements equivalent to Item
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procedure Delete
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(Container : in out Set;
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Item : Element_Type);
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-- Deletes from Container all of the elements equivalent to Item. If there
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-- are no elements equivalent to Item, then it raises Constraint_Error.
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procedure Delete
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(Container : in out Set;
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Position : in out Cursor);
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-- If Position equals No_Element, then Constraint_Error is raised. If
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-- Position is associated with a set different from Container, then
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-- Program_Error is raised. Otherwise, the node designated by Position is
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-- removed from Container, and Position is set to No_Element.
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procedure Delete_First (Container : in out Set);
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-- Removes the first node from Container
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procedure Delete_Last (Container : in out Set);
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-- Removes the last node from Container
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procedure Union (Target : in out Set; Source : Set);
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-- If Target is busy (cursor tampering is attempted), the Program_Error is
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-- raised. Otherwise, it inserts each element of Source into
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-- Target. Elements are inserted in the canonical order for multisets, such
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-- that the elements from Source are inserted after equivalent elements
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-- already in Target.
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function Union (Left, Right : Set) return Set;
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-- Returns a set comprising the all elements from Left and all of the
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-- elements from Right. The elements from Right follow the equivalent
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-- elements from Left.
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function "or" (Left, Right : Set) return Set renames Union;
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procedure Intersection (Target : in out Set; Source : Set);
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-- If Target denotes the same object as Source, the operation does
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-- nothing. If Target is busy (cursor tampering is attempted),
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-- Program_Error is raised. Otherwise, the elements in Target having no
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-- equivalent element in Source are deleted from Target.
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function Intersection (Left, Right : Set) return Set;
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-- If Left denotes the same object as Right, then the function returns a
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-- copy of Left. Otherwise, it returns a set comprising the equivalent
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-- elements from both Left and Right. Items are inserted in the result set
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-- in canonical order, such that the elements from Left precede the
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-- equivalent elements from Right.
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function "and" (Left, Right : Set) return Set renames Intersection;
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procedure Difference (Target : in out Set; Source : Set);
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-- If Target is busy (cursor tampering is attempted), then Program_Error is
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-- raised. Otherwise, the elements in Target that are equivalent to
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-- elements in Source are deleted from Target.
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function Difference (Left, Right : Set) return Set;
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-- Returns a set comprising the elements from Left that have no equivalent
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-- element in Right.
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function "-" (Left, Right : Set) return Set renames Difference;
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procedure Symmetric_Difference (Target : in out Set; Source : Set);
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-- If Target is busy, then Program_Error is raised. Otherwise, the elements
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-- in Target equivalent to elements in Source are deleted from Target, and
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-- the elements in Source not equivalent to elements in Target are inserted
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-- into Target.
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function Symmetric_Difference (Left, Right : Set) return Set;
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-- Returns a set comprising the union of the elements from Target having no
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-- equivalent in Source, and the elements of Source having no equivalent in
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-- Target.
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function "xor" (Left, Right : Set) return Set renames Symmetric_Difference;
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function Overlap (Left, Right : Set) return Boolean;
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-- Returns True if Left contains an element equivalent to an element of
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-- Right.
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function Is_Subset (Subset : Set; Of_Set : Set) return Boolean;
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-- Returns True if every element in Subset has an equivalent element in
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-- Of_Set.
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function First (Container : Set) return Cursor;
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-- If Container is empty, the function returns No_Element. Otherwise, it
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-- returns a cursor designating the smallest element.
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function First_Element (Container : Set) return Element_Type;
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-- Equivalent to Element (First (Container))
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function Last (Container : Set) return Cursor;
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-- If Container is empty, the function returns No_Element. Otherwise, it
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-- returns a cursor designating the largest element.
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function Last_Element (Container : Set) return Element_Type;
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-- Equivalent to Element (Last (Container))
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function Next (Position : Cursor) return Cursor;
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-- If Position equals No_Element or Last (Container), the function returns
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-- No_Element. Otherwise, it returns a cursor designating the node that
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-- immediately follows (as per the insertion order) the node designated by
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-- Position.
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procedure Next (Position : in out Cursor);
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-- Equivalent to Position := Next (Position)
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function Previous (Position : Cursor) return Cursor;
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-- If Position equals No_Element or First (Container), the function returns
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-- No_Element. Otherwise, it returns a cursor designating the node that
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-- immediately precedes (as per the insertion order) the node designated by
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-- Position.
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procedure Previous (Position : in out Cursor);
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-- Equivalent to Position := Previous (Position)
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function Find (Container : Set; Item : Element_Type) return Cursor;
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-- Returns a cursor designating the first element in Container equivalent
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-- to Item. If there is no equivalent element, it returns No_Element.
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function Floor (Container : Set; Item : Element_Type) return Cursor;
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-- If Container is empty, the function returns No_Element. If Item is
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-- equivalent to elements in Container, it returns a cursor designating the
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-- first equivalent element. Otherwise, it returns a cursor designating the
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-- largest element less than Item, or No_Element if all elements are
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-- greater than Item.
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function Ceiling (Container : Set; Item : Element_Type) return Cursor;
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-- If Container is empty, the function returns No_Element. If Item is
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-- equivalent to elements of Container, it returns a cursor designating the
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-- last equivalent element. Otherwise, it returns a cursor designating the
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-- smallest element greater than Item, or No_Element if all elements are
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-- less than Item.
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function Contains (Container : Set; Item : Element_Type) return Boolean;
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-- Equivalent to Container.Find (Item) /= No_Element
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function "<" (Left, Right : Cursor) return Boolean;
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-- Equivalent to Element (Left) < Element (Right)
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function ">" (Left, Right : Cursor) return Boolean;
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-- Equivalent to Element (Right) < Element (Left)
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function "<" (Left : Cursor; Right : Element_Type) return Boolean;
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-- Equivalent to Element (Left) < Right
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function ">" (Left : Cursor; Right : Element_Type) return Boolean;
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-- Equivalent to Right < Element (Left)
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function "<" (Left : Element_Type; Right : Cursor) return Boolean;
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-- Equivalent to Left < Element (Right)
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function ">" (Left : Element_Type; Right : Cursor) return Boolean;
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-- Equivalent to Element (Right) < Left
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procedure Iterate
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(Container : Set;
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Process : not null access procedure (Position : Cursor));
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-- Calls Process with a cursor designating each element of Container, in
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-- order from Container.First to Container.Last.
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procedure Reverse_Iterate
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(Container : Set;
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Process : not null access procedure (Position : Cursor));
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-- Calls Process with a cursor designating each element of Container, in
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-- order from Container.Last to Container.First.
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procedure Iterate
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(Container : Set;
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Item : Element_Type;
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Process : not null access procedure (Position : Cursor));
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-- Call Process with a cursor designating each element equivalent to Item,
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-- in order from Container.Floor (Item) to Container.Ceiling (Item).
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procedure Reverse_Iterate
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(Container : Set;
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Item : Element_Type;
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Process : not null access procedure (Position : Cursor));
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-- Call Process with a cursor designating each element equivalent to Item,
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-- in order from Container.Ceiling (Item) to Container.Floor (Item).
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function Iterate
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(Container : Set)
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return Set_Iterator_Interfaces.Reversible_Iterator'class;
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function Iterate
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(Container : Set;
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Start : Cursor)
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return Set_Iterator_Interfaces.Reversible_Iterator'class;
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generic
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type Key_Type (<>) is private;
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with function Key (Element : Element_Type) return Key_Type;
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with function "<" (Left, Right : Key_Type) return Boolean is <>;
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package Generic_Keys is
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function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
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-- Returns False if Left is less than Right, or Right is less than Left;
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-- otherwise, it returns True.
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function Key (Position : Cursor) return Key_Type;
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-- Equivalent to Key (Element (Position))
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function Element (Container : Set; Key : Key_Type) return Element_Type;
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-- Equivalent to Element (Find (Container, Key))
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procedure Exclude (Container : in out Set; Key : Key_Type);
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-- Deletes from Container any elements whose key is equivalent to Key
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procedure Delete (Container : in out Set; Key : Key_Type);
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-- Deletes from Container any elements whose key is equivalent to
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-- Key. If there are no such elements, then it raises Constraint_Error.
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function Find (Container : Set; Key : Key_Type) return Cursor;
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-- Returns a cursor designating the first element in Container whose key
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-- is equivalent to Key. If there is no equivalent element, it returns
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-- No_Element.
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function Floor (Container : Set; Key : Key_Type) return Cursor;
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-- If Container is empty, the function returns No_Element. If Item is
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-- equivalent to the keys of elements in Container, it returns a cursor
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-- designating the first such element. Otherwise, it returns a cursor
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-- designating the largest element whose key is less than Item, or
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-- No_Element if all keys are greater than Item.
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function Ceiling (Container : Set; Key : Key_Type) return Cursor;
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-- If Container is empty, the function returns No_Element. If Item is
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-- equivalent to the keys of elements of Container, it returns a cursor
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-- designating the last such element. Otherwise, it returns a cursor
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-- designating the smallest element whose key is greater than Item, or
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-- No_Element if all keys are less than Item.
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function Contains (Container : Set; Key : Key_Type) return Boolean;
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-- Equivalent to Find (Container, Key) /= No_Element
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procedure Update_Element -- Update_Element_Preserving_Key ???
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(Container : in out Set;
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Position : Cursor;
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Process : not null access
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procedure (Element : in out Element_Type));
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-- If Position equals No_Element, then Constraint_Error is raised. If
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-- Position is associated with a set object different from Container,
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-- then Program_Error is raised. Otherwise, it makes a copy of the key
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-- of the element designated by Position, and then calls Process with
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-- the element as the parameter. Update_Element then compares the key
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-- value obtained before calling Process to the key value obtained from
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-- the element after calling Process. If the keys are equivalent then
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-- the operation terminates. If Container is busy (cursor tampering has
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-- been attempted), then Program_Error is raised. Otherwise, the node
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-- is moved to its new position (in canonical order).
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procedure Iterate
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(Container : Set;
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Key : Key_Type;
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Process : not null access procedure (Position : Cursor));
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-- Call Process with a cursor designating each element equivalent to
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-- Key, in order from Floor (Container, Key) to
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-- Ceiling (Container, Key).
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procedure Reverse_Iterate
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(Container : Set;
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Key : Key_Type;
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Process : not null access procedure (Position : Cursor));
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-- Call Process with a cursor designating each element equivalent to
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-- Key, in order from Ceiling (Container, Key) to
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-- Floor (Container, Key).
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end Generic_Keys;
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private
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pragma Inline (Next);
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pragma Inline (Previous);
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type Node_Type;
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type Node_Access is access Node_Type;
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type Node_Type is limited record
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Parent : Node_Access;
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Left : Node_Access;
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Right : Node_Access;
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Color : Red_Black_Trees.Color_Type := Red_Black_Trees.Red;
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Element : Element_Type;
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end record;
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package Tree_Types is
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new Red_Black_Trees.Generic_Tree_Types (Node_Type, Node_Access);
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type Set is new Ada.Finalization.Controlled with record
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Tree : Tree_Types.Tree_Type;
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end record;
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overriding procedure Adjust (Container : in out Set);
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overriding procedure Finalize (Container : in out Set) renames Clear;
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use Red_Black_Trees;
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use Tree_Types, Tree_Types.Implementation;
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use Ada.Finalization;
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use Ada.Streams;
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type Set_Access is access all Set;
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for Set_Access'Storage_Size use 0;
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-- In all predefined libraries the following type is controlled, for proper
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-- management of tampering checks. For performance reason we omit this
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-- machinery for multisets, which are used in a number of our tools.
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type Reference_Control_Type is record
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Container : Set_Access;
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end record;
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type Constant_Reference_Type
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(Element : not null access constant Element_Type) is record
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Control : Reference_Control_Type :=
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|
raise Program_Error with "uninitialized reference";
|
|
-- The RM says, "The default initialization of an object of
|
|
-- type Constant_Reference_Type or Reference_Type propagates
|
|
-- Program_Error."
|
|
end record;
|
|
|
|
type Cursor is record
|
|
Container : Set_Access;
|
|
Node : Node_Access;
|
|
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 := Cursor'(null, null);
|
|
|
|
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;
|
|
|
|
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 others => <>);
|
|
|
|
type Iterator is new Limited_Controlled and
|
|
Set_Iterator_Interfaces.Reversible_Iterator with
|
|
record
|
|
Container : Set_Access;
|
|
Node : Node_Access;
|
|
end record
|
|
with Disable_Controlled => not T_Check;
|
|
|
|
overriding procedure Finalize (Object : in out Iterator);
|
|
|
|
overriding function First (Object : Iterator) return Cursor;
|
|
overriding function Last (Object : Iterator) return Cursor;
|
|
|
|
overriding function Next
|
|
(Object : Iterator;
|
|
Position : Cursor) return Cursor;
|
|
|
|
overriding function Previous
|
|
(Object : Iterator;
|
|
Position : Cursor) return Cursor;
|
|
|
|
end Ada.Containers.Ordered_Multisets;
|