469 lines
20 KiB
Ada
469 lines
20 KiB
Ada
------------------------------------------------------------------------------
|
|
-- --
|
|
-- GNAT LIBRARY COMPONENTS --
|
|
-- --
|
|
-- A D A . C O N T A I N E R S . B O U N D E D _ H A S H E D _ M A P S --
|
|
-- --
|
|
-- S p e c --
|
|
-- --
|
|
-- Copyright (C) 2004-2015, 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 --
|
|
-- apply solely to the contents of the part following the private keyword. --
|
|
-- --
|
|
-- 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. --
|
|
------------------------------------------------------------------------------
|
|
|
|
with Ada.Iterator_Interfaces;
|
|
|
|
private with Ada.Containers.Hash_Tables;
|
|
private with Ada.Streams;
|
|
private with Ada.Finalization;
|
|
|
|
generic
|
|
type Key_Type is private;
|
|
type Element_Type is private;
|
|
|
|
with function Hash (Key : Key_Type) return Hash_Type;
|
|
with function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
|
|
with function "=" (Left, Right : Element_Type) return Boolean is <>;
|
|
|
|
package Ada.Containers.Bounded_Hashed_Maps is
|
|
pragma Annotate (CodePeer, Skip_Analysis);
|
|
pragma Pure;
|
|
pragma Remote_Types;
|
|
|
|
type Map (Capacity : Count_Type; Modulus : Hash_Type) is tagged private with
|
|
Constant_Indexing => Constant_Reference,
|
|
Variable_Indexing => Reference,
|
|
Default_Iterator => Iterate,
|
|
Iterator_Element => Element_Type;
|
|
|
|
pragma Preelaborable_Initialization (Map);
|
|
|
|
type Cursor is private;
|
|
pragma Preelaborable_Initialization (Cursor);
|
|
|
|
Empty_Map : constant Map;
|
|
-- Map objects declared without an initialization expression are
|
|
-- initialized to the value Empty_Map.
|
|
|
|
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 Map_Iterator_Interfaces is new
|
|
Ada.Iterator_Interfaces (Cursor, Has_Element);
|
|
|
|
function "=" (Left, Right : Map) return Boolean;
|
|
-- For each key/element pair in Left, equality attempts to find the key in
|
|
-- Right; if a search fails the equality returns False. The search works by
|
|
-- calling Hash to find the bucket in the Right map that corresponds to the
|
|
-- Left key. If bucket is non-empty, then equality calls Equivalent_Keys
|
|
-- to compare the key (in Left) to the key of each node in the bucket (in
|
|
-- Right); if the keys are equivalent, then the equality test for this
|
|
-- key/element pair (in Left) completes by calling the element equality
|
|
-- operator to compare the element (in Left) to the element of the node
|
|
-- (in Right) whose key matched.
|
|
|
|
function Capacity (Container : Map) return Count_Type;
|
|
-- Returns the current capacity of the map. Capacity is the maximum length
|
|
-- before which rehashing in guaranteed not to occur.
|
|
|
|
procedure Reserve_Capacity (Container : in out Map; Capacity : Count_Type);
|
|
-- If the value of the Capacity actual parameter is less or equal to
|
|
-- Container.Capacity, then the operation has no effect. Otherwise it
|
|
-- raises Capacity_Error (as no expansion of capacity is possible for a
|
|
-- bounded form).
|
|
|
|
function Default_Modulus (Capacity : Count_Type) return Hash_Type;
|
|
-- Returns a modulus value (hash table size) which is optimal for the
|
|
-- specified capacity (which corresponds to the maximum number of items).
|
|
|
|
function Length (Container : Map) return Count_Type;
|
|
-- Returns the number of items in the map
|
|
|
|
function Is_Empty (Container : Map) return Boolean;
|
|
-- Equivalent to Length (Container) = 0
|
|
|
|
procedure Clear (Container : in out Map);
|
|
-- Removes all of the items from the map
|
|
|
|
function Key (Position : Cursor) return Key_Type;
|
|
-- Returns the key of the node designated by the cursor
|
|
|
|
function Element (Position : Cursor) return Element_Type;
|
|
-- Returns the element of the node designated by the cursor
|
|
|
|
procedure Replace_Element
|
|
(Container : in out Map;
|
|
Position : Cursor;
|
|
New_Item : Element_Type);
|
|
-- Assigns the value New_Item to the element designated by the cursor
|
|
|
|
procedure Query_Element
|
|
(Position : Cursor;
|
|
Process : not null access
|
|
procedure (Key : Key_Type; Element : Element_Type));
|
|
-- Calls Process with the key and element (both having only a constant
|
|
-- view) of the node designed by the cursor.
|
|
|
|
procedure Update_Element
|
|
(Container : in out Map;
|
|
Position : Cursor;
|
|
Process : not null access
|
|
procedure (Key : Key_Type; Element : in out Element_Type));
|
|
-- Calls Process with the key (with only a constant view) and element (with
|
|
-- a variable view) of the node designed by the cursor.
|
|
|
|
type Constant_Reference_Type
|
|
(Element : not null access constant Element_Type) is
|
|
private
|
|
with
|
|
Implicit_Dereference => Element;
|
|
|
|
type Reference_Type (Element : not null access Element_Type) is private
|
|
with
|
|
Implicit_Dereference => Element;
|
|
|
|
function Constant_Reference
|
|
(Container : aliased Map;
|
|
Position : Cursor) return Constant_Reference_Type;
|
|
|
|
function Reference
|
|
(Container : aliased in out Map;
|
|
Position : Cursor) return Reference_Type;
|
|
|
|
function Constant_Reference
|
|
(Container : aliased Map;
|
|
Key : Key_Type) return Constant_Reference_Type;
|
|
|
|
function Reference
|
|
(Container : aliased in out Map;
|
|
Key : Key_Type) return Reference_Type;
|
|
|
|
procedure Assign (Target : in out Map; Source : Map);
|
|
-- If Target denotes the same object as Source, then the operation has no
|
|
-- effect. If the Target capacity is less than the Source length, then
|
|
-- Assign raises Capacity_Error. Otherwise, Assign clears Target and then
|
|
-- copies the (active) elements from Source to Target.
|
|
|
|
function Copy
|
|
(Source : Map;
|
|
Capacity : Count_Type := 0;
|
|
Modulus : Hash_Type := 0) return Map;
|
|
-- Constructs a new set object whose elements correspond to Source. If the
|
|
-- Capacity parameter is 0, then the capacity of the result is the same as
|
|
-- the length of Source. If the Capacity parameter is equal or greater than
|
|
-- the length of Source, then the capacity of the result is the specified
|
|
-- value. Otherwise, Copy raises Capacity_Error. If the Modulus parameter
|
|
-- is 0, then the modulus of the result is the value returned by a call to
|
|
-- Default_Modulus with the capacity parameter determined as above;
|
|
-- otherwise the modulus of the result is the specified value.
|
|
|
|
procedure Move (Target : in out Map; Source : in out Map);
|
|
-- 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 Map;
|
|
Key : Key_Type;
|
|
New_Item : Element_Type;
|
|
Position : out Cursor;
|
|
Inserted : out Boolean);
|
|
-- Conditionally inserts New_Item into the map. If Key is already in the
|
|
-- map, then Inserted returns False and Position designates the node
|
|
-- containing the existing key/element pair (neither of which is modified).
|
|
-- If Key is not already in the map, the Inserted returns True and Position
|
|
-- designates the newly-inserted node container Key and New_Item. The
|
|
-- search for the key works as follows. Hash is called to determine Key's
|
|
-- bucket; if the bucket is non-empty, then Equivalent_Keys is called to
|
|
-- compare Key to each node in that bucket. If the bucket is empty, or
|
|
-- there were no matching keys in the bucket, the search "fails" and the
|
|
-- key/item pair is inserted in the map (and Inserted returns True);
|
|
-- otherwise, the search "succeeds" (and Inserted returns False).
|
|
|
|
procedure Insert
|
|
(Container : in out Map;
|
|
Key : Key_Type;
|
|
Position : out Cursor;
|
|
Inserted : out Boolean);
|
|
-- The same as the (conditional) Insert that accepts an element parameter,
|
|
-- with the difference that if Inserted returns True, then the element of
|
|
-- the newly-inserted node is initialized to its default value.
|
|
|
|
procedure Insert
|
|
(Container : in out Map;
|
|
Key : Key_Type;
|
|
New_Item : Element_Type);
|
|
-- Attempts to insert Key into the map, performing the usual search (which
|
|
-- involves calling both Hash and Equivalent_Keys); if the search succeeds
|
|
-- (because Key is already in the map), then it 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
|
|
-- Key is not already in the map.)
|
|
|
|
procedure Include
|
|
(Container : in out Map;
|
|
Key : Key_Type;
|
|
New_Item : Element_Type);
|
|
-- Attempts to insert Key into the map. If Key is already in the map, then
|
|
-- both the existing key and element are assigned the values of Key and
|
|
-- New_Item, respectively. (This version of Insert only raises an exception
|
|
-- if cursor tampering occurs. It is intended for use when you want to
|
|
-- insert the key/element pair in the map, and you don't care whether Key
|
|
-- is already present.)
|
|
|
|
procedure Replace
|
|
(Container : in out Map;
|
|
Key : Key_Type;
|
|
New_Item : Element_Type);
|
|
-- Searches for Key in the map; if the search fails (because Key was not in
|
|
-- the map), then it raises Constraint_Error. Otherwise, both the existing
|
|
-- key and element are assigned the values of Key and New_Item rsp. (This
|
|
-- is similar to Insert, but with the opposite exception behavior. It is to
|
|
-- be used when you want to assert that Key is already in the map.)
|
|
|
|
procedure Exclude (Container : in out Map; Key : Key_Type);
|
|
-- Searches for Key in the map, and if found, removes its node from the map
|
|
-- and then deallocates it. The search works as follows. The operation
|
|
-- calls Hash to determine the key's bucket; if the bucket is not empty, it
|
|
-- calls Equivalent_Keys to compare Key to each key in the bucket. (This is
|
|
-- the deletion analog of Include. It is intended for use when you want to
|
|
-- remove the item from the map, but don't care whether the key is already
|
|
-- in the map.)
|
|
|
|
procedure Delete (Container : in out Map; Key : Key_Type);
|
|
-- Searches for Key in the map (which involves calling both Hash and
|
|
-- Equivalent_Keys). If the search fails, then the operation raises
|
|
-- Constraint_Error. Otherwise it removes the node from the map 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 map.)
|
|
|
|
procedure Delete (Container : in out Map; Position : in out Cursor);
|
|
-- Removes the node designated by Position from the map, 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_Keys).
|
|
|
|
function First (Container : Map) 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 Find (Container : Map; Key : Key_Type) return Cursor;
|
|
-- Searches for Key in the map. Find calls Hash to determine the key's
|
|
-- bucket; if the bucket is not empty, it calls Equivalent_Keys to compare
|
|
-- Key to each key in the bucket. If the search succeeds, Find returns a
|
|
-- cursor designating the matching node; otherwise, it returns No_Element.
|
|
|
|
function Contains (Container : Map; Key : Key_Type) return Boolean;
|
|
-- Equivalent to Find (Container, Key) /= No_Element
|
|
|
|
function Element (Container : Map; Key : Key_Type) return Element_Type;
|
|
-- Equivalent to Element (Find (Container, Key))
|
|
|
|
function Equivalent_Keys (Left, Right : Cursor) return Boolean;
|
|
-- Returns the result of calling Equivalent_Keys with the keys of the nodes
|
|
-- designated by cursors Left and Right.
|
|
|
|
function Equivalent_Keys (Left : Cursor; Right : Key_Type) return Boolean;
|
|
-- Returns the result of calling Equivalent_Keys with key of the node
|
|
-- designated by Left and key Right.
|
|
|
|
function Equivalent_Keys (Left : Key_Type; Right : Cursor) return Boolean;
|
|
-- Returns the result of calling Equivalent_Keys with key Left and the node
|
|
-- designated by Right.
|
|
|
|
procedure Iterate
|
|
(Container : Map;
|
|
Process : not null access procedure (Position : Cursor));
|
|
-- Calls Process for each node in the map
|
|
|
|
function Iterate (Container : Map)
|
|
return Map_Iterator_Interfaces.Forward_Iterator'class;
|
|
|
|
private
|
|
pragma Inline (Length);
|
|
pragma Inline (Is_Empty);
|
|
pragma Inline (Clear);
|
|
pragma Inline (Key);
|
|
pragma Inline (Element);
|
|
pragma Inline (Move);
|
|
pragma Inline (Contains);
|
|
pragma Inline (Capacity);
|
|
pragma Inline (Reserve_Capacity);
|
|
pragma Inline (Has_Element);
|
|
pragma Inline (Next);
|
|
|
|
type Node_Type is record
|
|
Key : Key_Type;
|
|
Element : aliased Element_Type;
|
|
Next : Count_Type;
|
|
end record;
|
|
|
|
package HT_Types is
|
|
new Hash_Tables.Generic_Bounded_Hash_Table_Types (Node_Type);
|
|
|
|
type Map (Capacity : Count_Type; Modulus : Hash_Type) is
|
|
new HT_Types.Hash_Table_Type (Capacity, Modulus) with null record;
|
|
|
|
use HT_Types, HT_Types.Implementation;
|
|
use Ada.Streams;
|
|
use Ada.Finalization;
|
|
|
|
procedure Write
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Container : Map);
|
|
|
|
for Map'Write use Write;
|
|
|
|
procedure Read
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Container : out Map);
|
|
|
|
for Map'Read use Read;
|
|
|
|
type Map_Access is access all Map;
|
|
for Map_Access'Storage_Size use 0;
|
|
|
|
-- Note: If a Cursor object has no explicit initialization expression,
|
|
-- it must default initialize to the same value as constant No_Element.
|
|
-- The Node component of type Cursor has scalar type Count_Type, so it
|
|
-- requires an explicit initialization expression of its own declaration,
|
|
-- in order for objects of record type Cursor to properly initialize.
|
|
|
|
type Cursor is record
|
|
Container : Map_Access;
|
|
Node : Count_Type := 0;
|
|
end record;
|
|
|
|
procedure Read
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : out Cursor);
|
|
|
|
for Cursor'Read use Read;
|
|
|
|
procedure Write
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : Cursor);
|
|
|
|
for Cursor'Write use Write;
|
|
|
|
subtype Reference_Control_Type is Implementation.Reference_Control_Type;
|
|
-- It is necessary to rename this here, so that the compiler can find it
|
|
|
|
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;
|
|
|
|
procedure Write
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : Constant_Reference_Type);
|
|
|
|
for Constant_Reference_Type'Write use Write;
|
|
|
|
procedure Read
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : out Constant_Reference_Type);
|
|
|
|
for Constant_Reference_Type'Read use Read;
|
|
|
|
type Reference_Type (Element : not null access 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;
|
|
|
|
procedure Write
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : Reference_Type);
|
|
|
|
for Reference_Type'Write use Write;
|
|
|
|
procedure Read
|
|
(Stream : not null access Root_Stream_Type'Class;
|
|
Item : out Reference_Type);
|
|
|
|
for Reference_Type'Read use Read;
|
|
|
|
-- Three operations are used to optimize in the expansion of "for ... of"
|
|
-- loops: the Next(Cursor) procedure in the visible part, and the following
|
|
-- Pseudo_Reference and Get_Element_Access functions. See Sem_Ch5 for
|
|
-- details.
|
|
|
|
function Pseudo_Reference
|
|
(Container : aliased Map'Class) return Reference_Control_Type;
|
|
pragma Inline (Pseudo_Reference);
|
|
-- Creates an object of type Reference_Control_Type pointing to the
|
|
-- container, and increments the Lock. Finalization of this object will
|
|
-- decrement the Lock.
|
|
|
|
type Element_Access is access all Element_Type with
|
|
Storage_Size => 0;
|
|
|
|
function Get_Element_Access
|
|
(Position : Cursor) return not null Element_Access;
|
|
-- Returns a pointer to the element designated by Position.
|
|
|
|
Empty_Map : constant Map :=
|
|
(Hash_Table_Type with Capacity => 0, Modulus => 0);
|
|
|
|
No_Element : constant Cursor := (Container => null, Node => 0);
|
|
|
|
type Iterator is new Limited_Controlled and
|
|
Map_Iterator_Interfaces.Forward_Iterator with
|
|
record
|
|
Container : Map_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 Next
|
|
(Object : Iterator;
|
|
Position : Cursor) return Cursor;
|
|
|
|
end Ada.Containers.Bounded_Hashed_Maps;
|