------------------------------------------------------------------------------ -- -- -- 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 -- -- . -- -- -- -- 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;