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------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- 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 --
-- --
-- S p e c --
-- --
-- Copyright (C) 2004-2022, 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. --
------------------------------------------------------------------------------
-- The ordered multiset container is similar to the ordered set, but with the
-- difference that multiple equivalent elements are allowed. It also provides
-- additional operations, to iterate over items that are equivalent.
private with Ada.Containers.Red_Black_Trees;
private with Ada.Finalization;
private with Ada.Streams;
private with Ada.Strings.Text_Buffers;
with Ada.Iterator_Interfaces;
generic
type Element_Type is private;
with function "<" (Left, Right : Element_Type) return Boolean is <>;
with function "=" (Left, Right : Element_Type) return Boolean is <>;
package Ada.Containers.Ordered_Multisets with
SPARK_Mode => Off
is
pragma Annotate (CodePeer, Skip_Analysis);
pragma Preelaborate;
pragma Remote_Types;
function Equivalent_Elements (Left, Right : Element_Type) return Boolean;
-- Returns False if Left is less than Right, or Right is less than Left;
-- otherwise, it returns True.
type Set is tagged private
with Constant_Indexing => Constant_Reference,
Default_Iterator => Iterate,
Iterator_Element => Element_Type;
pragma Preelaborable_Initialization (Set);
type Cursor is private;
pragma Preelaborable_Initialization (Cursor);
Empty_Set : constant Set;
-- The default value for set objects declared without an explicit
-- initialization expression.
No_Element : constant Cursor;
-- The default value for cursor objects declared without an explicit
-- initialization expression.
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;
-- If Left denotes the same set object as Right, then equality returns
-- True. If the length of Left is different from the length of Right, then
-- it returns False. Otherwise, set equality iterates over Left and Right,
-- comparing the element of Left to the element of Right using the equality
-- operator for elements. If the elements compare False, then the iteration
-- terminates and set equality returns False. Otherwise, if all elements
-- compare True, then set equality returns True.
function Equivalent_Sets (Left, Right : Set) return Boolean;
-- Similar to set equality, but with the difference that elements are
-- compared for equivalence instead of equality.
function To_Set (New_Item : Element_Type) return Set;
-- Constructs a set object with New_Item as its single element
function Length (Container : Set) return Count_Type;
-- Returns the total number of elements in Container
function Is_Empty (Container : Set) return Boolean;
-- Returns True if Container.Length is 0
procedure Clear (Container : in out Set);
-- Deletes all elements from Container
function Element (Position : Cursor) return Element_Type;
-- If Position equals No_Element, then Constraint_Error is raised.
-- Otherwise, function Element returns the element designed by Position.
procedure Replace_Element
(Container : in out Set;
Position : Cursor;
New_Item : Element_Type);
-- If Position equals No_Element, then Constraint_Error is raised. If
-- Position is associated with a set different from Container, then
-- Program_Error is raised. If New_Item is equivalent to the element
-- designated by Position, then if Container is locked (element tampering
-- has been attempted), Program_Error is raised; otherwise, the element
-- designated by Position is assigned the value of New_Item. If New_Item is
-- not equivalent to the element designated by Position, then if the
-- container is busy (cursor tampering has been attempted), Program_Error
-- is raised; otherwise, the element designed by Position is assigned the
-- value of New_Item, and the node is moved to its new position (in
-- canonical insertion order).
procedure Query_Element
(Position : Cursor;
Process : not null access procedure (Element : Element_Type));
-- If Position equals No_Element, then Constraint_Error is
-- raised. Otherwise, it calls Process with the element designated by
-- Position as the parameter. This call locks the container, so attempts to
-- change the value of the element while Process is executing (to "tamper
-- with elements") will raise Program_Error.
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;
pragma Inline (Constant_Reference);
procedure Assign (Target : in out Set; Source : Set);
function Copy (Source : Set) return Set;
procedure Move (Target : in out Set; Source : in out Set);
-- If Target denotes the same object as Source, the operation does
-- nothing. If either Target or Source is busy (cursor tampering is
-- attempted), then it raises Program_Error. Otherwise, Target is cleared,
-- and the nodes from Source are moved (not copied) to Target (so Source
-- becomes empty).
procedure Insert
(Container : in out Set;
New_Item : Element_Type;
Position : out Cursor);
-- Insert adds New_Item to Container, and returns cursor Position
-- designating the newly inserted node. The node is inserted after any
-- existing elements less than or equivalent to New_Item (and before any
-- elements greater than New_Item). Note that the issue of where the new
-- node is inserted relative to equivalent elements does not arise for
-- unique-key containers, since in that case the insertion would simply
-- fail. For a multiple-key container (the case here), insertion always
-- succeeds, and is defined such that the new item is positioned after any
-- equivalent elements already in the container.
procedure Insert
(Container : in out Set;
New_Item : Element_Type);
-- Inserts New_Item in Container, but does not return a cursor designating
-- the newly-inserted node.
-- TODO: include Replace too???
--
-- procedure Replace
-- (Container : in out Set;
-- New_Item : Element_Type);
procedure Exclude
(Container : in out Set;
Item : Element_Type);
-- Deletes from Container all of the elements equivalent to Item
procedure Delete
(Container : in out Set;
Item : Element_Type);
-- Deletes from Container all of the elements equivalent to Item. If there
-- are no elements equivalent to Item, then it raises Constraint_Error.
procedure Delete
(Container : in out Set;
Position : in out Cursor);
-- If Position equals No_Element, then Constraint_Error is raised. If
-- Position is associated with a set different from Container, then
-- Program_Error is raised. Otherwise, the node designated by Position is
-- removed from Container, and Position is set to No_Element.
procedure Delete_First (Container : in out Set);
-- Removes the first node from Container
procedure Delete_Last (Container : in out Set);
-- Removes the last node from Container
procedure Union (Target : in out Set; Source : Set);
-- If Target is busy (cursor tampering is attempted), the Program_Error is
-- raised. Otherwise, it inserts each element of Source into
-- Target. Elements are inserted in the canonical order for multisets, such
-- that the elements from Source are inserted after equivalent elements
-- already in Target.
function Union (Left, Right : Set) return Set;
-- Returns a set comprising the all elements from Left and all of the
-- elements from Right. The elements from Right follow the equivalent
-- elements from Left.
function "or" (Left, Right : Set) return Set renames Union;
procedure Intersection (Target : in out Set; Source : Set);
-- If Target denotes the same object as Source, the operation does
-- nothing. If Target is busy (cursor tampering is attempted),
-- Program_Error is raised. Otherwise, the elements in Target having no
-- equivalent element in Source are deleted from Target.
function Intersection (Left, Right : Set) return Set;
-- If Left denotes the same object as Right, then the function returns a
-- copy of Left. Otherwise, it returns a set comprising the equivalent
-- elements from both Left and Right. Items are inserted in the result set
-- in canonical order, such that the elements from Left precede the
-- equivalent elements from Right.
function "and" (Left, Right : Set) return Set renames Intersection;
procedure Difference (Target : in out Set; Source : Set);
-- If Target is busy (cursor tampering is attempted), then Program_Error is
-- raised. Otherwise, the elements in Target that are equivalent to
-- elements in Source are deleted from Target.
function Difference (Left, Right : Set) return Set;
-- Returns a set comprising the elements from Left that have no equivalent
-- element in Right.
function "-" (Left, Right : Set) return Set renames Difference;
procedure Symmetric_Difference (Target : in out Set; Source : Set);
-- If Target is busy, then Program_Error is raised. Otherwise, the elements
-- in Target equivalent to elements in Source are deleted from Target, and
-- the elements in Source not equivalent to elements in Target are inserted
-- into Target.
function Symmetric_Difference (Left, Right : Set) return Set;
-- Returns a set comprising the union of the elements from Target having no
-- equivalent in Source, and the elements of Source having no equivalent in
-- Target.
function "xor" (Left, Right : Set) return Set renames Symmetric_Difference;
function Overlap (Left, Right : Set) return Boolean;
-- Returns True if Left contains an element equivalent to an element of
-- Right.
function Is_Subset (Subset : Set; Of_Set : Set) return Boolean;
-- Returns True if every element in Subset has an equivalent element in
-- Of_Set.
function First (Container : Set) return Cursor;
-- If Container is empty, the function returns No_Element. Otherwise, it
-- returns a cursor designating the smallest element.
function First_Element (Container : Set) return Element_Type;
-- Equivalent to Element (First (Container))
function Last (Container : Set) return Cursor;
-- If Container is empty, the function returns No_Element. Otherwise, it
-- returns a cursor designating the largest element.
function Last_Element (Container : Set) return Element_Type;
-- Equivalent to Element (Last (Container))
function Next (Position : Cursor) return Cursor;
-- If Position equals No_Element or Last (Container), the function returns
-- No_Element. Otherwise, it returns a cursor designating the node that
-- immediately follows (as per the insertion order) the node designated by
-- Position.
procedure Next (Position : in out Cursor);
-- Equivalent to Position := Next (Position)
function Previous (Position : Cursor) return Cursor;
-- If Position equals No_Element or First (Container), the function returns
-- No_Element. Otherwise, it returns a cursor designating the node that
-- immediately precedes (as per the insertion order) the node designated by
-- Position.
procedure Previous (Position : in out Cursor);
-- Equivalent to Position := Previous (Position)
function Find (Container : Set; Item : Element_Type) return Cursor;
-- Returns a cursor designating the first element in Container equivalent
-- to Item. If there is no equivalent element, it returns No_Element.
function Floor (Container : Set; Item : Element_Type) return Cursor;
-- If Container is empty, the function returns No_Element. If Item is
-- equivalent to elements in Container, it returns a cursor designating the
-- first equivalent element. Otherwise, it returns a cursor designating the
-- largest element less than Item, or No_Element if all elements are
-- greater than Item.
function Ceiling (Container : Set; Item : Element_Type) return Cursor;
-- If Container is empty, the function returns No_Element. If Item is
-- equivalent to elements of Container, it returns a cursor designating the
-- last equivalent element. Otherwise, it returns a cursor designating the
-- smallest element greater than Item, or No_Element if all elements are
-- less than Item.
function Contains (Container : Set; Item : Element_Type) return Boolean;
-- Equivalent to Container.Find (Item) /= No_Element
function "<" (Left, Right : Cursor) return Boolean;
-- Equivalent to Element (Left) < Element (Right)
function ">" (Left, Right : Cursor) return Boolean;
-- Equivalent to Element (Right) < Element (Left)
function "<" (Left : Cursor; Right : Element_Type) return Boolean;
-- Equivalent to Element (Left) < Right
function ">" (Left : Cursor; Right : Element_Type) return Boolean;
-- Equivalent to Right < Element (Left)
function "<" (Left : Element_Type; Right : Cursor) return Boolean;
-- Equivalent to Left < Element (Right)
function ">" (Left : Element_Type; Right : Cursor) return Boolean;
-- Equivalent to Element (Right) < Left
procedure Iterate
(Container : Set;
Process : not null access procedure (Position : Cursor));
-- Calls Process with a cursor designating each element of Container, in
-- order from Container.First to Container.Last.
procedure Reverse_Iterate
(Container : Set;
Process : not null access procedure (Position : Cursor));
-- Calls Process with a cursor designating each element of Container, in
-- order from Container.Last to Container.First.
procedure Iterate
(Container : Set;
Item : Element_Type;
Process : not null access procedure (Position : Cursor));
-- Call Process with a cursor designating each element equivalent to Item,
-- in order from Container.Floor (Item) to Container.Ceiling (Item).
procedure Reverse_Iterate
(Container : Set;
Item : Element_Type;
Process : not null access procedure (Position : Cursor));
-- Call Process with a cursor designating each element equivalent to Item,
-- in order from Container.Ceiling (Item) to Container.Floor (Item).
function Iterate
(Container : Set)
return Set_Iterator_Interfaces.Reversible_Iterator'class;
function Iterate
(Container : Set;
Start : Cursor)
return Set_Iterator_Interfaces.Reversible_Iterator'class;
generic
type Key_Type (<>) is private;
with function Key (Element : Element_Type) return Key_Type;
with function "<" (Left, Right : Key_Type) return Boolean is <>;
package Generic_Keys is
function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
-- Returns False if Left is less than Right, or Right is less than Left;
-- otherwise, it returns True.
function Key (Position : Cursor) return Key_Type;
-- Equivalent to Key (Element (Position))
function Element (Container : Set; Key : Key_Type) return Element_Type;
-- Equivalent to Element (Find (Container, Key))
procedure Exclude (Container : in out Set; Key : Key_Type);
-- Deletes from Container any elements whose key is equivalent to Key
procedure Delete (Container : in out Set; Key : Key_Type);
-- Deletes from Container any elements whose key is equivalent to
-- Key. If there are no such elements, then it raises Constraint_Error.
function Find (Container : Set; Key : Key_Type) return Cursor;
-- Returns a cursor designating the first element in Container whose key
-- is equivalent to Key. If there is no equivalent element, it returns
-- No_Element.
function Floor (Container : Set; Key : Key_Type) return Cursor;
-- If Container is empty, the function returns No_Element. If Item is
-- equivalent to the keys of elements in Container, it returns a cursor
-- designating the first such element. Otherwise, it returns a cursor
-- designating the largest element whose key is less than Item, or
-- No_Element if all keys are greater than Item.
function Ceiling (Container : Set; Key : Key_Type) return Cursor;
-- If Container is empty, the function returns No_Element. If Item is
-- equivalent to the keys of elements of Container, it returns a cursor
-- designating the last such element. Otherwise, it returns a cursor
-- designating the smallest element whose key is greater than Item, or
-- No_Element if all keys are less than Item.
function Contains (Container : Set; Key : Key_Type) return Boolean;
-- Equivalent to Find (Container, Key) /= No_Element
procedure Update_Element -- Update_Element_Preserving_Key ???
(Container : in out Set;
Position : Cursor;
Process : not null access
procedure (Element : in out Element_Type));
-- If Position equals No_Element, then Constraint_Error is raised. If
-- Position is associated with a set object different from Container,
-- then Program_Error is raised. Otherwise, it makes a copy of the key
-- of the element designated by Position, and then calls Process with
-- the element as the parameter. Update_Element then compares the key
-- value obtained before calling Process to the key value obtained from
-- the element after calling Process. If the keys are equivalent then
-- the operation terminates. If Container is busy (cursor tampering has
-- been attempted), then Program_Error is raised. Otherwise, the node
-- is moved to its new position (in canonical order).
procedure Iterate
(Container : Set;
Key : Key_Type;
Process : not null access procedure (Position : Cursor));
-- Call Process with a cursor designating each element equivalent to
-- Key, in order from Floor (Container, Key) to
-- Ceiling (Container, Key).
procedure Reverse_Iterate
(Container : Set;
Key : Key_Type;
Process : not null access procedure (Position : Cursor));
-- Call Process with a cursor designating each element equivalent to
-- Key, in order from Ceiling (Container, Key) to
-- Floor (Container, Key).
end Generic_Keys;
private
pragma Inline (Next);
pragma Inline (Previous);
type Node_Type;
type Node_Access is access Node_Type;
type Node_Type is limited record
Parent : Node_Access;
Left : Node_Access;
Right : Node_Access;
Color : Red_Black_Trees.Color_Type := Red_Black_Trees.Red;
Element : Element_Type;
end record;
package Tree_Types is
new Red_Black_Trees.Generic_Tree_Types (Node_Type, Node_Access);
type Set is new Ada.Finalization.Controlled with record
Tree : Tree_Types.Tree_Type;
end record with Put_Image => Put_Image;
procedure Put_Image
(S : in out Ada.Strings.Text_Buffers.Root_Buffer_Type'Class; V : Set);
overriding procedure Adjust (Container : in out Set);
overriding procedure Finalize (Container : in out Set) renames Clear;
use Red_Black_Trees;
use Tree_Types, Tree_Types.Implementation;
use Ada.Finalization;
use Ada.Streams;
type Set_Access is access all Set;
for Set_Access'Storage_Size use 0;
-- In all predefined libraries the following type is controlled, for proper
-- management of tampering checks. For performance reason we omit this
-- machinery for multisets, which are used in a number of our tools.
type Reference_Control_Type is record
Container : Set_Access;
end record;
type Constant_Reference_Type
(Element : not null access constant Element_Type) is record
Control : Reference_Control_Type :=
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;