1------------------------------------------------------------------------------ 2-- -- 3-- GNAT LIBRARY COMPONENTS -- 4-- -- 5-- ADA.CONTAINERS.INDEFINITE_HASHED_MAPS -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2004-2018, 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.Indefinite_Hashed_Maps is 49 pragma Annotate (CodePeer, Skip_Analysis); 50 pragma Preelaborate; 51 pragma Remote_Types; 52 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; 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 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. 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 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. 130 131 procedure Update_Element 132 (Container : in out Map; 133 Position : Cursor; 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. 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 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.) 204 205 procedure Include 206 (Container : in out Map; 207 Key : Key_Type; 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.) 215 216 procedure Replace 217 (Container : in out Map; 218 Key : Key_Type; 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 225 -- map.) 226 227 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 234 -- in the map.) 235 236 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.) 243 244 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). 249 250 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. 253 254 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. 261 262 procedure Next (Position : in out Cursor); 263 -- Equivalent to Position := Next (Position) 264 265 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. 270 271 function Contains (Container : Map; Key : Key_Type) return Boolean; 272 -- Equivalent to Find (Container, Key) /= No_Element 273 274 function Element (Container : Map; Key : Key_Type) return Element_Type; 275 -- Equivalent to Element (Find (Container, Key)) 276 277 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. 280 281 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. 284 285 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. 288 289 procedure Iterate 290 (Container : Map; 291 Process : not null access procedure (Position : Cursor)); 292 -- Calls Process for each node in the map 293 294 function Iterate (Container : Map) 295 return Map_Iterator_Interfaces.Forward_Iterator'class; 296 297private 298 pragma Inline ("="); 299 pragma Inline (Length); 300 pragma Inline (Is_Empty); 301 pragma Inline (Clear); 302 pragma Inline (Key); 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); 311 312 type Node_Type; 313 type Node_Access is access Node_Type; 314 315 type Key_Access is access Key_Type; 316 type Element_Access is access all Element_Type; 317 318 type Node_Type is limited record 319 Key : Key_Access; 320 Element : Element_Access; 321 Next : Node_Access; 322 end record; 323 324 package HT_Types is 325 new Hash_Tables.Generic_Hash_Table_Types (Node_Type, Node_Access); 326 327 type Map is new Ada.Finalization.Controlled with record 328 HT : HT_Types.Hash_Table_Type; 329 end record; 330 331 overriding procedure Adjust (Container : in out Map); 332 333 overriding procedure Finalize (Container : in out Map); 334 335 use HT_Types, HT_Types.Implementation; 336 use Ada.Finalization; 337 use Ada.Streams; 338 339 procedure Write 340 (Stream : not null access Root_Stream_Type'Class; 341 Container : Map); 342 343 for Map'Write use Write; 344 345 procedure Read 346 (Stream : not null access Root_Stream_Type'Class; 347 Container : out Map); 348 349 for Map'Read use Read; 350 351 type Map_Access is access all Map; 352 for Map_Access'Storage_Size use 0; 353 354 type Cursor is record 355 Container : Map_Access; 356 Node : Node_Access; 357 Position : Hash_Type := Hash_Type'Last; 358 end record; 359 360 procedure Write 361 (Stream : not null access Root_Stream_Type'Class; 362 Item : Cursor); 363 364 for Cursor'Write use Write; 365 366 procedure Read 367 (Stream : not null access Root_Stream_Type'Class; 368 Item : out Cursor); 369 370 for Cursor'Read use Read; 371 372 subtype Reference_Control_Type is Implementation.Reference_Control_Type; 373 -- It is necessary to rename this here, so that the compiler can find it 374 375 type Constant_Reference_Type 376 (Element : not null access constant Element_Type) is 377 record 378 Control : Reference_Control_Type := 379 raise Program_Error with "uninitialized reference"; 380 -- The RM says, "The default initialization of an object of 381 -- type Constant_Reference_Type or Reference_Type propagates 382 -- Program_Error." 383 end record; 384 385 procedure Write 386 (Stream : not null access Root_Stream_Type'Class; 387 Item : Constant_Reference_Type); 388 389 for Constant_Reference_Type'Write use Write; 390 391 procedure Read 392 (Stream : not null access Root_Stream_Type'Class; 393 Item : out Constant_Reference_Type); 394 395 for Constant_Reference_Type'Read use Read; 396 397 type Reference_Type 398 (Element : not null access Element_Type) is 399 record 400 Control : Reference_Control_Type := 401 raise Program_Error with "uninitialized reference"; 402 -- The RM says, "The default initialization of an object of 403 -- type Constant_Reference_Type or Reference_Type propagates 404 -- Program_Error." 405 end record; 406 407 procedure Write 408 (Stream : not null access Root_Stream_Type'Class; 409 Item : Reference_Type); 410 411 for Reference_Type'Write use Write; 412 413 procedure Read 414 (Stream : not null access Root_Stream_Type'Class; 415 Item : out Reference_Type); 416 417 for Reference_Type'Read use Read; 418 419 -- Three operations are used to optimize in the expansion of "for ... of" 420 -- loops: the Next(Cursor) procedure in the visible part, and the following 421 -- Pseudo_Reference and Get_Element_Access functions. See Sem_Ch5 for 422 -- details. 423 424 function Pseudo_Reference 425 (Container : aliased Map'Class) return Reference_Control_Type; 426 pragma Inline (Pseudo_Reference); 427 -- Creates an object of type Reference_Control_Type pointing to the 428 -- container, and increments the Lock. Finalization of this object will 429 -- decrement the Lock. 430 431 function Get_Element_Access 432 (Position : Cursor) return not null Element_Access; 433 -- Returns a pointer to the element designated by Position. 434 435 Empty_Map : constant Map := (Controlled with others => <>); 436 437 No_Element : constant Cursor := 438 (Container => null, Node => null, Position => Hash_Type'Last); 439 440 type Iterator is new Limited_Controlled and 441 Map_Iterator_Interfaces.Forward_Iterator with 442 record 443 Container : Map_Access; 444 end record 445 with Disable_Controlled => not T_Check; 446 447 overriding procedure Finalize (Object : in out Iterator); 448 449 overriding function First (Object : Iterator) return Cursor; 450 451 overriding function Next 452 (Object : Iterator; 453 Position : Cursor) return Cursor; 454 455end Ada.Containers.Indefinite_Hashed_Maps; 456