1 ------------------------------------------------------------------------------
3 -- GNAT LIBRARY COMPONENTS --
5 -- ADA.CONTAINERS.INDEFINITE_HASHED_MAPS --
9 -- Copyright (C) 2004-2015, Free Software Foundation, Inc. --
11 -- This specification is derived from the Ada Reference Manual for use with --
12 -- GNAT. The copyright notice above, and the license provisions that follow --
13 -- apply solely to the contents of the part following the private keyword. --
15 -- GNAT is free software; you can redistribute it and/or modify it under --
16 -- terms of the GNU General Public License as published by the Free Soft- --
17 -- ware Foundation; either version 3, or (at your option) any later ver- --
18 -- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
19 -- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
20 -- or FITNESS FOR A PARTICULAR PURPOSE. --
22 -- As a special exception under Section 7 of GPL version 3, you are granted --
23 -- additional permissions described in the GCC Runtime Library Exception, --
24 -- version 3.1, as published by the Free Software Foundation. --
26 -- You should have received a copy of the GNU General Public License and --
27 -- a copy of the GCC Runtime Library Exception along with this program; --
28 -- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see --
29 -- <http://www.gnu.org/licenses/>. --
31 -- This unit was originally developed by Matthew J Heaney. --
32 ------------------------------------------------------------------------------
34 with Ada
.Iterator_Interfaces
;
36 private with Ada
.Containers
.Hash_Tables
;
37 private with Ada
.Finalization
;
38 private with Ada
.Streams
;
41 type Key_Type
(<>) is private;
42 type Element_Type
(<>) is private;
44 with function Hash
(Key
: Key_Type
) return Hash_Type
;
45 with function Equivalent_Keys
(Left
, Right
: Key_Type
) return Boolean;
46 with function "=" (Left
, Right
: Element_Type
) return Boolean is <>;
48 package Ada
.Containers
.Indefinite_Hashed_Maps
is
49 pragma Annotate
(CodePeer
, Skip_Analysis
);
53 type Map
is tagged private with
54 Constant_Indexing
=> Constant_Reference
,
55 Variable_Indexing
=> Reference
,
56 Default_Iterator
=> Iterate
,
57 Iterator_Element
=> Element_Type
;
59 pragma Preelaborable_Initialization
(Map
);
61 type Cursor
is private;
62 pragma Preelaborable_Initialization
(Cursor
);
64 Empty_Map
: constant Map
;
65 -- Map objects declared without an initialization expression are
66 -- initialized to the value Empty_Map.
68 No_Element
: constant Cursor
;
69 -- Cursor objects declared without an initialization expression are
70 -- initialized to the value No_Element.
72 function Has_Element
(Position
: Cursor
) return Boolean;
73 -- Equivalent to Position /= No_Element
75 package Map_Iterator_Interfaces
is new
76 Ada
.Iterator_Interfaces
(Cursor
, Has_Element
);
78 overriding
function "=" (Left
, Right
: Map
) return Boolean;
79 -- For each key/element pair in Left, equality attempts to find the key in
80 -- Right; if a search fails the equality returns False. The search works by
81 -- calling Hash to find the bucket in the Right map that corresponds to the
82 -- Left key. If bucket is non-empty, then equality calls Equivalent_Keys
83 -- to compare the key (in Left) to the key of each node in the bucket (in
84 -- Right); if the keys are equivalent, then the equality test for this
85 -- key/element pair (in Left) completes by calling the element equality
86 -- operator to compare the element (in Left) to the element of the node
87 -- (in Right) whose key matched.
89 function Capacity
(Container
: Map
) return Count_Type
;
90 -- Returns the current capacity of the map. Capacity is the maximum length
91 -- before which rehashing in guaranteed not to occur.
93 procedure Reserve_Capacity
(Container
: in out Map
; Capacity
: Count_Type
);
94 -- Adjusts the current capacity, by allocating a new buckets array. If the
95 -- requested capacity is less than the current capacity, then the capacity
96 -- is contracted (to a value not less than the current length). If the
97 -- requested capacity is greater than the current capacity, then the
98 -- capacity is expanded (to a value not less than what is requested). In
99 -- either case, the nodes are rehashed from the old buckets array onto the
100 -- new buckets array (Hash is called once for each existing key in order to
101 -- compute the new index), and then the old buckets array is deallocated.
103 function Length
(Container
: Map
) return Count_Type
;
104 -- Returns the number of items in the map
106 function Is_Empty
(Container
: Map
) return Boolean;
107 -- Equivalent to Length (Container) = 0
109 procedure Clear
(Container
: in out Map
);
110 -- Removes all of the items from the map
112 function Key
(Position
: Cursor
) return Key_Type
;
113 -- Returns the key of the node designated by the cursor
115 function Element
(Position
: Cursor
) return Element_Type
;
116 -- Returns the element of the node designated by the cursor
118 procedure Replace_Element
119 (Container
: in out Map
;
121 New_Item
: Element_Type
);
122 -- Assigns the value New_Item to the element designated by the cursor
124 procedure Query_Element
126 Process
: not null access procedure (Key
: Key_Type
;
127 Element
: Element_Type
));
128 -- Calls Process with the key and element (both having only a constant
129 -- view) of the node designed by the cursor.
131 procedure Update_Element
132 (Container
: in out Map
;
134 Process
: not null access procedure (Key
: Key_Type
;
135 Element
: in out Element_Type
));
136 -- Calls Process with the key (with only a constant view) and element (with
137 -- a variable view) of the node designed by the cursor.
139 type Constant_Reference_Type
140 (Element
: not null access constant Element_Type
) is private
142 Implicit_Dereference
=> Element
;
144 type Reference_Type
(Element
: not null access Element_Type
) is private
146 Implicit_Dereference
=> Element
;
148 function Constant_Reference
149 (Container
: aliased Map
;
150 Position
: Cursor
) return Constant_Reference_Type
;
151 pragma Inline
(Constant_Reference
);
154 (Container
: aliased in out Map
;
155 Position
: Cursor
) return Reference_Type
;
156 pragma Inline
(Reference
);
158 function Constant_Reference
159 (Container
: aliased Map
;
160 Key
: Key_Type
) return Constant_Reference_Type
;
161 pragma Inline
(Constant_Reference
);
164 (Container
: aliased in out Map
;
165 Key
: Key_Type
) return Reference_Type
;
166 pragma Inline
(Reference
);
168 procedure Assign
(Target
: in out Map
; Source
: Map
);
170 function Copy
(Source
: Map
; Capacity
: Count_Type
:= 0) return Map
;
172 procedure Move
(Target
: in out Map
; Source
: in out Map
);
173 -- Clears Target (if it's not empty), and then moves (not copies) the
174 -- buckets array and nodes from Source to Target.
177 (Container
: in out Map
;
179 New_Item
: Element_Type
;
180 Position
: out Cursor
;
181 Inserted
: out Boolean);
182 -- Conditionally inserts New_Item into the map. If Key is already in the
183 -- map, then Inserted returns False and Position designates the node
184 -- containing the existing key/element pair (neither of which is modified).
185 -- If Key is not already in the map, the Inserted returns True and Position
186 -- designates the newly-inserted node container Key and New_Item. The
187 -- search for the key works as follows. Hash is called to determine Key's
188 -- bucket; if the bucket is non-empty, then Equivalent_Keys is called to
189 -- compare Key to each node in that bucket. If the bucket is empty, or
190 -- there were no matching keys in the bucket, the search "fails" and the
191 -- key/item pair is inserted in the map (and Inserted returns True);
192 -- otherwise, the search "succeeds" (and Inserted returns False).
195 (Container
: in out Map
;
197 New_Item
: Element_Type
);
198 -- Attempts to insert Key into the map, performing the usual search (which
199 -- involves calling both Hash and Equivalent_Keys); if the search succeeds
200 -- (because Key is already in the map), then it raises Constraint_Error.
201 -- (This version of Insert is similar to Replace, but having the opposite
202 -- exception behavior. It is intended for use when you want to assert that
203 -- Key is not already in the map.)
206 (Container
: in out Map
;
208 New_Item
: Element_Type
);
209 -- Attempts to insert Key into the map. If Key is already in the map, then
210 -- both the existing key and element are assigned the values of Key and
211 -- New_Item, respectively. (This version of Insert only raises an exception
212 -- if cursor tampering occurs. It is intended for use when you want to
213 -- insert the key/element pair in the map, and you don't care whether Key
214 -- is already present.)
217 (Container
: in out Map
;
219 New_Item
: Element_Type
);
220 -- Searches for Key in the map; if the search fails (because Key was not in
221 -- the map), then it raises Constraint_Error. Otherwise, both the existing
222 -- key and element are assigned the values of Key and New_Item rsp. (This
223 -- is similar to Insert, but with the opposite exception behavior. It is
224 -- intended for use when you want to assert that Key is already in the
227 procedure Exclude
(Container
: in out Map
; Key
: Key_Type
);
228 -- Searches for Key in the map, and if found, removes its node from the map
229 -- and then deallocates it. The search works as follows. The operation
230 -- calls Hash to determine the key's bucket; if the bucket is not empty, it
231 -- calls Equivalent_Keys to compare Key to each key in the bucket. (This is
232 -- the deletion analog of Include. It is intended for use when you want to
233 -- remove the item from the map, but don't care whether the key is already
236 procedure Delete
(Container
: in out Map
; Key
: Key_Type
);
237 -- Searches for Key in the map (which involves calling both Hash and
238 -- Equivalent_Keys). If the search fails, then the operation raises
239 -- Constraint_Error. Otherwise it removes the node from the map and then
240 -- deallocates it. (This is the deletion analog of non-conditional
241 -- Insert. It is intended for use when you want to assert that the item is
242 -- already in the map.)
244 procedure Delete
(Container
: in out Map
; Position
: in out Cursor
);
245 -- Removes the node designated by Position from the map, and then
246 -- deallocates the node. The operation calls Hash to determine the bucket,
247 -- and then compares Position to each node in the bucket until there's a
248 -- match (it does not call Equivalent_Keys).
250 function First
(Container
: Map
) return Cursor
;
251 -- Returns a cursor that designates the first non-empty bucket, by
252 -- searching from the beginning of the buckets array.
254 function Next
(Position
: Cursor
) return Cursor
;
255 -- Returns a cursor that designates the node that follows the current one
256 -- designated by Position. If Position designates the last node in its
257 -- bucket, the operation calls Hash to compute the index of this bucket,
258 -- and searches the buckets array for the first non-empty bucket, starting
259 -- from that index; otherwise, it simply follows the link to the next node
260 -- in the same bucket.
262 procedure Next
(Position
: in out Cursor
);
263 -- Equivalent to Position := Next (Position)
265 function Find
(Container
: Map
; Key
: Key_Type
) return Cursor
;
266 -- Searches for Key in the map. Find calls Hash to determine the key's
267 -- bucket; if the bucket is not empty, it calls Equivalent_Keys to compare
268 -- Key to each key in the bucket. If the search succeeds, Find returns a
269 -- cursor designating the matching node; otherwise, it returns No_Element.
271 function Contains
(Container
: Map
; Key
: Key_Type
) return Boolean;
272 -- Equivalent to Find (Container, Key) /= No_Element
274 function Element
(Container
: Map
; Key
: Key_Type
) return Element_Type
;
275 -- Equivalent to Element (Find (Container, Key))
277 function Equivalent_Keys
(Left
, Right
: Cursor
) return Boolean;
278 -- Returns the result of calling Equivalent_Keys with the keys of the nodes
279 -- designated by cursors Left and Right.
281 function Equivalent_Keys
(Left
: Cursor
; Right
: Key_Type
) return Boolean;
282 -- Returns the result of calling Equivalent_Keys with key of the node
283 -- designated by Left and key Right.
285 function Equivalent_Keys
(Left
: Key_Type
; Right
: Cursor
) return Boolean;
286 -- Returns the result of calling Equivalent_Keys with key Left and the node
287 -- designated by Right.
291 Process
: not null access procedure (Position
: Cursor
));
292 -- Calls Process for each node in the map
294 function Iterate
(Container
: Map
)
295 return Map_Iterator_Interfaces
.Forward_Iterator
'class;
299 pragma Inline
(Length
);
300 pragma Inline
(Is_Empty
);
301 pragma Inline
(Clear
);
303 pragma Inline
(Element
);
304 pragma Inline
(Move
);
305 pragma Inline
(Contains
);
306 pragma Inline
(Capacity
);
307 pragma Inline
(Reserve_Capacity
);
308 pragma Inline
(Has_Element
);
309 pragma Inline
(Equivalent_Keys
);
310 pragma Inline
(Next
);
313 type Node_Access
is access Node_Type
;
315 type Key_Access
is access Key_Type
;
316 type Element_Access
is access all Element_Type
;
318 type Node_Type
is limited record
320 Element
: Element_Access
;
325 new Hash_Tables
.Generic_Hash_Table_Types
(Node_Type
, Node_Access
);
327 type Map
is new Ada
.Finalization
.Controlled
with record
328 HT
: HT_Types
.Hash_Table_Type
;
331 overriding
procedure Adjust
(Container
: in out Map
);
333 overriding
procedure Finalize
(Container
: in out Map
);
335 use HT_Types
, HT_Types
.Implementation
;
336 use Ada
.Finalization
;
340 (Stream
: not null access Root_Stream_Type
'Class;
343 for Map
'Write use Write
;
346 (Stream
: not null access Root_Stream_Type
'Class;
347 Container
: out Map
);
349 for Map
'Read use Read
;
351 type Map_Access
is access all Map
;
352 for Map_Access
'Storage_Size use 0;
354 type Cursor
is record
355 Container
: Map_Access
;
360 (Stream
: not null access Root_Stream_Type
'Class;
363 for Cursor
'Write use Write
;
366 (Stream
: not null access Root_Stream_Type
'Class;
369 for Cursor
'Read use Read
;
371 subtype Reference_Control_Type
is Implementation
.Reference_Control_Type
;
372 -- It is necessary to rename this here, so that the compiler can find it
374 type Constant_Reference_Type
375 (Element
: not null access constant Element_Type
) is
377 Control
: Reference_Control_Type
:=
378 raise Program_Error
with "uninitialized reference";
379 -- The RM says, "The default initialization of an object of
380 -- type Constant_Reference_Type or Reference_Type propagates
385 (Stream
: not null access Root_Stream_Type
'Class;
386 Item
: Constant_Reference_Type
);
388 for Constant_Reference_Type
'Write use Write
;
391 (Stream
: not null access Root_Stream_Type
'Class;
392 Item
: out Constant_Reference_Type
);
394 for Constant_Reference_Type
'Read use Read
;
397 (Element
: not null access Element_Type
) is
399 Control
: Reference_Control_Type
:=
400 raise Program_Error
with "uninitialized reference";
401 -- The RM says, "The default initialization of an object of
402 -- type Constant_Reference_Type or Reference_Type propagates
407 (Stream
: not null access Root_Stream_Type
'Class;
408 Item
: Reference_Type
);
410 for Reference_Type
'Write use Write
;
413 (Stream
: not null access Root_Stream_Type
'Class;
414 Item
: out Reference_Type
);
416 for Reference_Type
'Read use Read
;
418 -- Three operations are used to optimize in the expansion of "for ... of"
419 -- loops: the Next(Cursor) procedure in the visible part, and the following
420 -- Pseudo_Reference and Get_Element_Access functions. See Sem_Ch5 for
423 function Pseudo_Reference
424 (Container
: aliased Map
'Class) return Reference_Control_Type
;
425 pragma Inline
(Pseudo_Reference
);
426 -- Creates an object of type Reference_Control_Type pointing to the
427 -- container, and increments the Lock. Finalization of this object will
428 -- decrement the Lock.
430 function Get_Element_Access
431 (Position
: Cursor
) return not null Element_Access
;
432 -- Returns a pointer to the element designated by Position.
434 Empty_Map
: constant Map
:= (Controlled
with others => <>);
436 No_Element
: constant Cursor
:= (Container
=> null, Node
=> null);
438 type Iterator
is new Limited_Controlled
and
439 Map_Iterator_Interfaces
.Forward_Iterator
with
441 Container
: Map_Access
;
443 with Disable_Controlled
=> not T_Check
;
445 overriding
procedure Finalize
(Object
: in out Iterator
);
447 overriding
function First
(Object
: Iterator
) return Cursor
;
449 overriding
function Next
451 Position
: Cursor
) return Cursor
;
453 end Ada
.Containers
.Indefinite_Hashed_Maps
;