1------------------------------------------------------------------------------ 2-- -- 3-- GNAT LIBRARY COMPONENTS -- 4-- -- 5-- A D A . C O N T A I N E R S . H A S H E D _ M A P S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2004-2012, Free Software Foundation, Inc. -- 10-- -- 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. -- 14-- -- 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. -- 21-- -- 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. -- 25-- -- 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/>. -- 30-- -- 31-- This unit was originally developed by Matthew J Heaney. -- 32------------------------------------------------------------------------------ 33 34with Ada.Iterator_Interfaces; 35 36private with Ada.Containers.Hash_Tables; 37private with Ada.Finalization; 38private with Ada.Streams; 39 40generic 41 type Key_Type is private; 42 type Element_Type is private; 43 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 <>; 47 48package Ada.Containers.Hashed_Maps is 49 pragma Preelaborate; 50 pragma Remote_Types; 51 52 type Map is tagged private 53 with 54 Constant_Indexing => Constant_Reference, 55 Variable_Indexing => Reference, 56 Default_Iterator => Iterate, 57 Iterator_Element => Element_Type; 58 59 pragma Preelaborable_Initialization (Map); 60 61 type Cursor is private; 62 pragma Preelaborable_Initialization (Cursor); 63 64 Empty_Map : constant Map; 65 -- Map objects declared without an initialization expression are 66 -- initialized to the value Empty_Map. 67 68 No_Element : constant Cursor; 69 -- Cursor objects declared without an initialization expression are 70 -- initialized to the value No_Element. 71 72 function Has_Element (Position : Cursor) return Boolean; 73 -- Equivalent to Position /= No_Element 74 75 package Map_Iterator_Interfaces is new 76 Ada.Iterator_Interfaces (Cursor, Has_Element); 77 78 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. 88 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. 92 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. 102 103 function Length (Container : Map) return Count_Type; 104 -- Returns the number of items in the map 105 106 function Is_Empty (Container : Map) return Boolean; 107 -- Equivalent to Length (Container) = 0 108 109 procedure Clear (Container : in out Map); 110 -- Removes all of the items from the map 111 112 function Key (Position : Cursor) return Key_Type; 113 -- Returns the key of the node designated by the cursor 114 115 function Element (Position : Cursor) return Element_Type; 116 -- Returns the element of the node designated by the cursor 117 118 procedure Replace_Element 119 (Container : in out Map; 120 Position : Cursor; 121 New_Item : Element_Type); 122 -- Assigns the value New_Item to the element designated by the cursor 123 124 procedure Query_Element 125 (Position : Cursor; 126 Process : not null access 127 procedure (Key : Key_Type; 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. 130 131 procedure Update_Element 132 (Container : in out Map; 133 Position : Cursor; 134 Process : not null access 135 procedure (Key : Key_Type; 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. 138 139 type Constant_Reference_Type 140 (Element : not null access constant Element_Type) is private 141 with 142 Implicit_Dereference => Element; 143 144 type Reference_Type (Element : not null access Element_Type) is private 145 with 146 Implicit_Dereference => Element; 147 148 function Constant_Reference 149 (Container : aliased Map; 150 Position : Cursor) return Constant_Reference_Type; 151 pragma Inline (Constant_Reference); 152 153 function Reference 154 (Container : aliased in out Map; 155 Position : Cursor) return Reference_Type; 156 pragma Inline (Reference); 157 158 function Constant_Reference 159 (Container : aliased Map; 160 Key : Key_Type) return Constant_Reference_Type; 161 pragma Inline (Constant_Reference); 162 163 function Reference 164 (Container : aliased in out Map; 165 Key : Key_Type) return Reference_Type; 166 pragma Inline (Reference); 167 168 procedure Assign (Target : in out Map; Source : Map); 169 170 function Copy (Source : Map; Capacity : Count_Type := 0) return Map; 171 172 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. 175 176 procedure Insert 177 (Container : in out Map; 178 Key : Key_Type; 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). 193 194 procedure Insert 195 (Container : in out Map; 196 Key : Key_Type; 197 Position : out Cursor; 198 Inserted : out Boolean); 199 -- The same as the (conditional) Insert that accepts an element parameter, 200 -- with the difference that if Inserted returns True, then the element of 201 -- the newly-inserted node is initialized to its default value. 202 203 procedure Insert 204 (Container : in out Map; 205 Key : Key_Type; 206 New_Item : Element_Type); 207 -- Attempts to insert Key into the map, performing the usual search (which 208 -- involves calling both Hash and Equivalent_Keys); if the search succeeds 209 -- (because Key is already in the map), then it raises Constraint_Error. 210 -- (This version of Insert is similar to Replace, but having the opposite 211 -- exception behavior. It is intended for use when you want to assert that 212 -- Key is not already in the map.) 213 214 procedure Include 215 (Container : in out Map; 216 Key : Key_Type; 217 New_Item : Element_Type); 218 -- Attempts to insert Key into the map. If Key is already in the map, then 219 -- both the existing key and element are assigned the values of Key and 220 -- New_Item, respectively. (This version of Insert only raises an exception 221 -- if cursor tampering occurs. It is intended for use when you want to 222 -- insert the key/element pair in the map, and you don't care whether Key 223 -- is already present.) 224 225 procedure Replace 226 (Container : in out Map; 227 Key : Key_Type; 228 New_Item : Element_Type); 229 -- Searches for Key in the map; if the search fails (because Key was not in 230 -- the map), then it raises Constraint_Error. Otherwise, both the existing 231 -- key and element are assigned the values of Key and New_Item rsp. (This 232 -- is similar to Insert, but with the opposite exception behavior. It is to 233 -- be used when you want to assert that Key is already in the map.) 234 235 procedure Exclude (Container : in out Map; Key : Key_Type); 236 -- Searches for Key in the map, and if found, removes its node from the map 237 -- and then deallocates it. The search works as follows. The operation 238 -- calls Hash to determine the key's bucket; if the bucket is not empty, it 239 -- calls Equivalent_Keys to compare Key to each key in the bucket. (This is 240 -- the deletion analog of Include. It is intended for use when you want to 241 -- remove the item from the map, but don't care whether the key is already 242 -- in the map.) 243 244 procedure Delete (Container : in out Map; Key : Key_Type); 245 -- Searches for Key in the map (which involves calling both Hash and 246 -- Equivalent_Keys). If the search fails, then the operation raises 247 -- Constraint_Error. Otherwise it removes the node from the map and then 248 -- deallocates it. (This is the deletion analog of non-conditional 249 -- Insert. It is intended for use when you want to assert that the item is 250 -- already in the map.) 251 252 procedure Delete (Container : in out Map; Position : in out Cursor); 253 -- Removes the node designated by Position from the map, and then 254 -- deallocates the node. The operation calls Hash to determine the bucket, 255 -- and then compares Position to each node in the bucket until there's a 256 -- match (it does not call Equivalent_Keys). 257 258 function First (Container : Map) return Cursor; 259 -- Returns a cursor that designates the first non-empty bucket, by 260 -- searching from the beginning of the buckets array. 261 262 function Next (Position : Cursor) return Cursor; 263 -- Returns a cursor that designates the node that follows the current one 264 -- designated by Position. If Position designates the last node in its 265 -- bucket, the operation calls Hash to compute the index of this bucket, 266 -- and searches the buckets array for the first non-empty bucket, starting 267 -- from that index; otherwise, it simply follows the link to the next node 268 -- in the same bucket. 269 270 procedure Next (Position : in out Cursor); 271 -- Equivalent to Position := Next (Position) 272 273 function Find (Container : Map; Key : Key_Type) return Cursor; 274 -- Searches for Key in the map. Find calls Hash to determine the key's 275 -- bucket; if the bucket is not empty, it calls Equivalent_Keys to compare 276 -- Key to each key in the bucket. If the search succeeds, Find returns a 277 -- cursor designating the matching node; otherwise, it returns No_Element. 278 279 function Contains (Container : Map; Key : Key_Type) return Boolean; 280 -- Equivalent to Find (Container, Key) /= No_Element 281 282 function Element (Container : Map; Key : Key_Type) return Element_Type; 283 -- Equivalent to Element (Find (Container, Key)) 284 285 function Equivalent_Keys (Left, Right : Cursor) return Boolean; 286 -- Returns the result of calling Equivalent_Keys with the keys of the nodes 287 -- designated by cursors Left and Right. 288 289 function Equivalent_Keys (Left : Cursor; Right : Key_Type) return Boolean; 290 -- Returns the result of calling Equivalent_Keys with key of the node 291 -- designated by Left and key Right. 292 293 function Equivalent_Keys (Left : Key_Type; Right : Cursor) return Boolean; 294 -- Returns the result of calling Equivalent_Keys with key Left and the node 295 -- designated by Right. 296 297 procedure Iterate 298 (Container : Map; 299 Process : not null access procedure (Position : Cursor)); 300 -- Calls Process for each node in the map 301 302 function Iterate 303 (Container : Map) return Map_Iterator_Interfaces.Forward_Iterator'class; 304 305private 306 pragma Inline ("="); 307 pragma Inline (Length); 308 pragma Inline (Is_Empty); 309 pragma Inline (Clear); 310 pragma Inline (Key); 311 pragma Inline (Element); 312 pragma Inline (Move); 313 pragma Inline (Contains); 314 pragma Inline (Capacity); 315 pragma Inline (Reserve_Capacity); 316 pragma Inline (Has_Element); 317 pragma Inline (Equivalent_Keys); 318 pragma Inline (Next); 319 320 type Node_Type; 321 type Node_Access is access Node_Type; 322 323 type Node_Type is limited record 324 Key : Key_Type; 325 Element : aliased Element_Type; 326 Next : Node_Access; 327 end record; 328 329 package HT_Types is 330 new Hash_Tables.Generic_Hash_Table_Types (Node_Type, Node_Access); 331 332 type Map is new Ada.Finalization.Controlled with record 333 HT : HT_Types.Hash_Table_Type; 334 end record; 335 336 overriding procedure Adjust (Container : in out Map); 337 338 overriding procedure Finalize (Container : in out Map); 339 340 use HT_Types; 341 use Ada.Finalization; 342 use Ada.Streams; 343 344 procedure Write 345 (Stream : not null access Root_Stream_Type'Class; 346 Container : Map); 347 348 for Map'Write use Write; 349 350 procedure Read 351 (Stream : not null access Root_Stream_Type'Class; 352 Container : out Map); 353 354 for Map'Read use Read; 355 356 type Map_Access is access all Map; 357 for Map_Access'Storage_Size use 0; 358 359 type Cursor is record 360 Container : Map_Access; 361 Node : Node_Access; 362 end record; 363 364 procedure Read 365 (Stream : not null access Root_Stream_Type'Class; 366 Item : out Cursor); 367 368 for Cursor'Read use Read; 369 370 procedure Write 371 (Stream : not null access Root_Stream_Type'Class; 372 Item : Cursor); 373 374 for Cursor'Write use Write; 375 376 type Reference_Control_Type is 377 new Controlled with record 378 Container : Map_Access; 379 end record; 380 381 overriding procedure Adjust (Control : in out Reference_Control_Type); 382 pragma Inline (Adjust); 383 384 overriding procedure Finalize (Control : in out Reference_Control_Type); 385 pragma Inline (Finalize); 386 387 type Constant_Reference_Type 388 (Element : not null access constant Element_Type) is 389 record 390 Control : Reference_Control_Type; 391 end record; 392 393 procedure Write 394 (Stream : not null access Root_Stream_Type'Class; 395 Item : Constant_Reference_Type); 396 397 for Constant_Reference_Type'Write use Write; 398 399 procedure Read 400 (Stream : not null access Root_Stream_Type'Class; 401 Item : out Constant_Reference_Type); 402 403 for Constant_Reference_Type'Read use Read; 404 405 type Reference_Type 406 (Element : not null access Element_Type) is 407 record 408 Control : Reference_Control_Type; 409 end record; 410 411 procedure Write 412 (Stream : not null access Root_Stream_Type'Class; 413 Item : Reference_Type); 414 415 for Reference_Type'Write use Write; 416 417 procedure Read 418 (Stream : not null access Root_Stream_Type'Class; 419 Item : out Reference_Type); 420 421 for Reference_Type'Read use Read; 422 423 Empty_Map : constant Map := (Controlled with HT => (null, 0, 0, 0)); 424 425 No_Element : constant Cursor := (Container => null, Node => null); 426 427end Ada.Containers.Hashed_Maps; 428