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
52 type Map is tagged private with
53 Constant_Indexing => Constant_Reference,
54 Variable_Indexing => Reference,
55 Default_Iterator => Iterate,
56 Iterator_Element => Element_Type;
58 pragma Preelaborable_Initialization (Map);
60 type Cursor is private;
61 pragma Preelaborable_Initialization (Cursor);
63 Empty_Map : constant Map;
64 -- Map objects declared without an initialization expression are
65 -- initialized to the value Empty_Map.
67 No_Element : constant Cursor;
68 -- Cursor objects declared without an initialization expression are
69 -- initialized to the value No_Element.
71 function Has_Element (Position : Cursor) return Boolean;
72 -- Equivalent to Position /= No_Element
74 package Map_Iterator_Interfaces is new
75 Ada.Iterator_Interfaces (Cursor, Has_Element);
77 overriding function "=" (Left, Right : Map) return Boolean;
78 -- For each key/element pair in Left, equality attempts to find the key in
79 -- Right; if a search fails the equality returns False. The search works by
80 -- calling Hash to find the bucket in the Right map that corresponds to the
81 -- Left key. If bucket is non-empty, then equality calls Equivalent_Keys
82 -- to compare the key (in Left) to the key of each node in the bucket (in
83 -- Right); if the keys are equivalent, then the equality test for this
84 -- key/element pair (in Left) completes by calling the element equality
85 -- operator to compare the element (in Left) to the element of the node
86 -- (in Right) whose key matched.
88 function Capacity (Container : Map) return Count_Type;
89 -- Returns the current capacity of the map. Capacity is the maximum length
90 -- before which rehashing in guaranteed not to occur.
92 procedure Reserve_Capacity (Container : in out Map; Capacity : Count_Type);
93 -- Adjusts the current capacity, by allocating a new buckets array. If the
94 -- requested capacity is less than the current capacity, then the capacity
95 -- is contracted (to a value not less than the current length). If the
96 -- requested capacity is greater than the current capacity, then the
97 -- capacity is expanded (to a value not less than what is requested). In
98 -- either case, the nodes are rehashed from the old buckets array onto the
99 -- new buckets array (Hash is called once for each existing key in order to
100 -- compute the new index), and then the old buckets array is deallocated.
102 function Length (Container : Map) return Count_Type;
103 -- Returns the number of items in the map
105 function Is_Empty (Container : Map) return Boolean;
106 -- Equivalent to Length (Container) = 0
108 procedure Clear (Container : in out Map);
109 -- Removes all of the items from the map
111 function Key (Position : Cursor) return Key_Type;
112 -- Returns the key of the node designated by the cursor
114 function Element (Position : Cursor) return Element_Type;
115 -- Returns the element of the node designated by the cursor
117 procedure Replace_Element
118 (Container : in out Map;
120 New_Item : Element_Type);
121 -- Assigns the value New_Item to the element designated by the cursor
123 procedure Query_Element
125 Process : not null access procedure (Key : Key_Type;
126 Element : Element_Type));
127 -- Calls Process with the key and element (both having only a constant
128 -- view) of the node designed by the cursor.
130 procedure Update_Element
131 (Container : in out Map;
133 Process : not null access procedure (Key : Key_Type;
134 Element : in out Element_Type));
135 -- Calls Process with the key (with only a constant view) and element (with
136 -- a variable view) of the node designed by the cursor.
138 type Constant_Reference_Type
139 (Element : not null access constant Element_Type) is private
141 Implicit_Dereference => Element;
143 type Reference_Type (Element : not null access Element_Type) is private
145 Implicit_Dereference => Element;
147 function Constant_Reference
148 (Container : aliased Map;
149 Position : Cursor) return Constant_Reference_Type;
150 pragma Inline (Constant_Reference);
153 (Container : aliased in out Map;
154 Position : Cursor) return Reference_Type;
155 pragma Inline (Reference);
157 function Constant_Reference
158 (Container : aliased Map;
159 Key : Key_Type) return Constant_Reference_Type;
160 pragma Inline (Constant_Reference);
163 (Container : aliased in out Map;
164 Key : Key_Type) return Reference_Type;
165 pragma Inline (Reference);
167 procedure Assign (Target : in out Map; Source : Map);
169 function Copy (Source : Map; Capacity : Count_Type := 0) return Map;
171 procedure Move (Target : in out Map; Source : in out Map);
172 -- Clears Target (if it's not empty), and then moves (not copies) the
173 -- buckets array and nodes from Source to Target.
176 (Container : in out Map;
178 New_Item : Element_Type;
179 Position : out Cursor;
180 Inserted : out Boolean);
181 -- Conditionally inserts New_Item into the map. If Key is already in the
182 -- map, then Inserted returns False and Position designates the node
183 -- containing the existing key/element pair (neither of which is modified).
184 -- If Key is not already in the map, the Inserted returns True and Position
185 -- designates the newly-inserted node container Key and New_Item. The
186 -- search for the key works as follows. Hash is called to determine Key's
187 -- bucket; if the bucket is non-empty, then Equivalent_Keys is called to
188 -- compare Key to each node in that bucket. If the bucket is empty, or
189 -- there were no matching keys in the bucket, the search "fails" and the
190 -- key/item pair is inserted in the map (and Inserted returns True);
191 -- otherwise, the search "succeeds" (and Inserted returns False).
194 (Container : in out Map;
196 New_Item : Element_Type);
197 -- Attempts to insert Key into the map, performing the usual search (which
198 -- involves calling both Hash and Equivalent_Keys); if the search succeeds
199 -- (because Key is already in the map), then it raises Constraint_Error.
200 -- (This version of Insert is similar to Replace, but having the opposite
201 -- exception behavior. It is intended for use when you want to assert that
202 -- Key is not already in the map.)
205 (Container : in out Map;
207 New_Item : Element_Type);
208 -- Attempts to insert Key into the map. If Key is already in the map, then
209 -- both the existing key and element are assigned the values of Key and
210 -- New_Item, respectively. (This version of Insert only raises an exception
211 -- if cursor tampering occurs. It is intended for use when you want to
212 -- insert the key/element pair in the map, and you don't care whether Key
213 -- is already present.)
216 (Container : in out Map;
218 New_Item : Element_Type);
219 -- Searches for Key in the map; if the search fails (because Key was not in
220 -- the map), then it raises Constraint_Error. Otherwise, both the existing
221 -- key and element are assigned the values of Key and New_Item rsp. (This
222 -- is similar to Insert, but with the opposite exception behavior. It is
223 -- intended for use when you want to assert that Key is already in the
226 procedure Exclude (Container : in out Map; Key : Key_Type);
227 -- Searches for Key in the map, and if found, removes its node from the map
228 -- and then deallocates it. The search works as follows. The operation
229 -- calls Hash to determine the key's bucket; if the bucket is not empty, it
230 -- calls Equivalent_Keys to compare Key to each key in the bucket. (This is
231 -- the deletion analog of Include. It is intended for use when you want to
232 -- remove the item from the map, but don't care whether the key is already
235 procedure Delete (Container : in out Map; Key : Key_Type);
236 -- Searches for Key in the map (which involves calling both Hash and
237 -- Equivalent_Keys). If the search fails, then the operation raises
238 -- Constraint_Error. Otherwise it removes the node from the map and then
239 -- deallocates it. (This is the deletion analog of non-conditional
240 -- Insert. It is intended for use when you want to assert that the item is
241 -- already in the map.)
243 procedure Delete (Container : in out Map; Position : in out Cursor);
244 -- Removes the node designated by Position from the map, and then
245 -- deallocates the node. The operation calls Hash to determine the bucket,
246 -- and then compares Position to each node in the bucket until there's a
247 -- match (it does not call Equivalent_Keys).
249 function First (Container : Map) return Cursor;
250 -- Returns a cursor that designates the first non-empty bucket, by
251 -- searching from the beginning of the buckets array.
253 function Next (Position : Cursor) return Cursor;
254 -- Returns a cursor that designates the node that follows the current one
255 -- designated by Position. If Position designates the last node in its
256 -- bucket, the operation calls Hash to compute the index of this bucket,
257 -- and searches the buckets array for the first non-empty bucket, starting
258 -- from that index; otherwise, it simply follows the link to the next node
259 -- in the same bucket.
261 procedure Next (Position : in out Cursor);
262 -- Equivalent to Position := Next (Position)
264 function Find (Container : Map; Key : Key_Type) return Cursor;
265 -- Searches for Key in the map. Find calls Hash to determine the key's
266 -- bucket; if the bucket is not empty, it calls Equivalent_Keys to compare
267 -- Key to each key in the bucket. If the search succeeds, Find returns a
268 -- cursor designating the matching node; otherwise, it returns No_Element.
270 function Contains (Container : Map; Key : Key_Type) return Boolean;
271 -- Equivalent to Find (Container, Key) /= No_Element
273 function Element (Container : Map; Key : Key_Type) return Element_Type;
274 -- Equivalent to Element (Find (Container, Key))
276 function Equivalent_Keys (Left, Right : Cursor) return Boolean;
277 -- Returns the result of calling Equivalent_Keys with the keys of the nodes
278 -- designated by cursors Left and Right.
280 function Equivalent_Keys (Left : Cursor; Right : Key_Type) return Boolean;
281 -- Returns the result of calling Equivalent_Keys with key of the node
282 -- designated by Left and key Right.
284 function Equivalent_Keys (Left : Key_Type; Right : Cursor) return Boolean;
285 -- Returns the result of calling Equivalent_Keys with key Left and the node
286 -- designated by Right.
290 Process : not null access procedure (Position : Cursor));
291 -- Calls Process for each node in the map
293 function Iterate (Container : Map)
294 return Map_Iterator_Interfaces.Forward_Iterator'class;
298 pragma Inline (Length);
299 pragma Inline (Is_Empty);
300 pragma Inline (Clear);
302 pragma Inline (Element);
303 pragma Inline (Move);
304 pragma Inline (Contains);
305 pragma Inline (Capacity);
306 pragma Inline (Reserve_Capacity);
307 pragma Inline (Has_Element);
308 pragma Inline (Equivalent_Keys);
309 pragma Inline (Next);
312 type Node_Access is access Node_Type;
314 type Key_Access is access Key_Type;
315 type Element_Access is access Element_Type;
317 type Node_Type is limited record
319 Element : Element_Access;
324 new Hash_Tables.Generic_Hash_Table_Types (Node_Type, Node_Access);
326 type Map is new Ada.Finalization.Controlled with record
327 HT : HT_Types.Hash_Table_Type;
330 overriding procedure Adjust (Container : in out Map);
332 overriding procedure Finalize (Container : in out Map);
335 use Ada.Finalization;
339 (Stream : not null access Root_Stream_Type'Class;
342 for Map'Write use Write;
345 (Stream : not null access Root_Stream_Type'Class;
346 Container : out Map);
348 for Map'Read use Read;
350 type Map_Access is access all Map;
351 for Map_Access'Storage_Size use 0;
353 type Cursor is record
354 Container : Map_Access;
359 (Stream : not null access Root_Stream_Type'Class;
362 for Cursor'Write use Write;
365 (Stream : not null access Root_Stream_Type'Class;
368 for Cursor'Read use Read;
370 type Reference_Control_Type is
371 new Controlled with record
372 Container : Map_Access;
375 overriding procedure Adjust (Control : in out Reference_Control_Type);
376 pragma Inline (Adjust);
378 overriding procedure Finalize (Control : in out Reference_Control_Type);
379 pragma Inline (Finalize);
381 type Constant_Reference_Type
382 (Element : not null access constant Element_Type) is
384 Control : Reference_Control_Type :=
385 raise Program_Error with "uninitialized reference";
386 -- The RM says, "The default initialization of an object of
387 -- type Constant_Reference_Type or Reference_Type propagates
392 (Stream : not null access Root_Stream_Type'Class;
393 Item : Constant_Reference_Type);
395 for Constant_Reference_Type'Write use Write;
398 (Stream : not null access Root_Stream_Type'Class;
399 Item : out Constant_Reference_Type);
401 for Constant_Reference_Type'Read use Read;
404 (Element : not null access Element_Type) is
406 Control : Reference_Control_Type :=
407 raise Program_Error with "uninitialized reference";
408 -- The RM says, "The default initialization of an object of
409 -- type Constant_Reference_Type or Reference_Type propagates
414 (Stream : not null access Root_Stream_Type'Class;
415 Item : Reference_Type);
417 for Reference_Type'Write use Write;
420 (Stream : not null access Root_Stream_Type'Class;
421 Item : out Reference_Type);
423 for Reference_Type'Read use Read;
425 Empty_Map : constant Map := (Controlled with HT => (null, 0, 0, 0));
427 No_Element : constant Cursor := (Container => null, Node => null);
429 type Iterator is new Limited_Controlled and
430 Map_Iterator_Interfaces.Forward_Iterator with
432 Container : Map_Access;
435 overriding procedure Finalize (Object : in out Iterator);
437 overriding function First (Object : Iterator) return Cursor;
439 overriding function Next
441 Position : Cursor) return Cursor;
443 end Ada.Containers.Indefinite_Hashed_Maps;