1------------------------------------------------------------------------------ 2-- -- 3-- GNAT LIBRARY COMPONENTS -- 4-- -- 5-- 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 -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2004-2013, 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.Streams; 38private with Ada.Finalization; 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.Bounded_Hashed_Maps is 49 pragma Pure; 50 pragma Remote_Types; 51 52 type Map (Capacity : Count_Type; Modulus : Hash_Type) is tagged private with 53 Constant_Indexing => Constant_Reference, 54 Variable_Indexing => Reference, 55 Default_Iterator => Iterate, 56 Iterator_Element => Element_Type; 57 58 pragma Preelaborable_Initialization (Map); 59 60 type Cursor is private; 61 pragma Preelaborable_Initialization (Cursor); 62 63 Empty_Map : constant Map; 64 -- Map objects declared without an initialization expression are 65 -- initialized to the value Empty_Map. 66 67 No_Element : constant Cursor; 68 -- Cursor objects declared without an initialization expression are 69 -- initialized to the value No_Element. 70 71 function Has_Element (Position : Cursor) return Boolean; 72 -- Equivalent to Position /= No_Element 73 74 package Map_Iterator_Interfaces is new 75 Ada.Iterator_Interfaces (Cursor, Has_Element); 76 77 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. 87 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. 91 92 procedure Reserve_Capacity (Container : in out Map; Capacity : Count_Type); 93 -- If the value of the Capacity actual parameter is less or equal to 94 -- Container.Capacity, then the operation has no effect. Otherwise it 95 -- raises Capacity_Error (as no expansion of capacity is possible for a 96 -- bounded form). 97 98 function Default_Modulus (Capacity : Count_Type) return Hash_Type; 99 -- Returns a modulus value (hash table size) which is optimal for the 100 -- specified capacity (which corresponds to the maximum number of items). 101 102 function Length (Container : Map) return Count_Type; 103 -- Returns the number of items in the map 104 105 function Is_Empty (Container : Map) return Boolean; 106 -- Equivalent to Length (Container) = 0 107 108 procedure Clear (Container : in out Map); 109 -- Removes all of the items from the map 110 111 function Key (Position : Cursor) return Key_Type; 112 -- Returns the key of the node designated by the cursor 113 114 function Element (Position : Cursor) return Element_Type; 115 -- Returns the element of the node designated by the cursor 116 117 procedure Replace_Element 118 (Container : in out Map; 119 Position : Cursor; 120 New_Item : Element_Type); 121 -- Assigns the value New_Item to the element designated by the cursor 122 123 procedure Query_Element 124 (Position : Cursor; 125 Process : not null access 126 procedure (Key : Key_Type; 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. 129 130 procedure Update_Element 131 (Container : in out Map; 132 Position : Cursor; 133 Process : not null access 134 procedure (Key : Key_Type; 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. 137 138 type Constant_Reference_Type 139 (Element : not null access constant Element_Type) is 140 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; 151 152 function Reference 153 (Container : aliased in out Map; 154 Position : Cursor) return Reference_Type; 155 156 function Constant_Reference 157 (Container : aliased Map; 158 Key : Key_Type) return Constant_Reference_Type; 159 160 function Reference 161 (Container : aliased in out Map; 162 Key : Key_Type) return Reference_Type; 163 164 procedure Assign (Target : in out Map; Source : Map); 165 -- If Target denotes the same object as Source, then the operation has no 166 -- effect. If the Target capacity is less than the Source length, then 167 -- Assign raises Capacity_Error. Otherwise, Assign clears Target and then 168 -- copies the (active) elements from Source to Target. 169 170 function Copy 171 (Source : Map; 172 Capacity : Count_Type := 0; 173 Modulus : Hash_Type := 0) return Map; 174 -- Constructs a new set object whose elements correspond to Source. If the 175 -- Capacity parameter is 0, then the capacity of the result is the same as 176 -- the length of Source. If the Capacity parameter is equal or greater than 177 -- the length of Source, then the capacity of the result is the specified 178 -- value. Otherwise, Copy raises Capacity_Error. If the Modulus parameter 179 -- is 0, then the modulus of the result is the value returned by a call to 180 -- Default_Modulus with the capacity parameter determined as above; 181 -- otherwise the modulus of the result is the specified value. 182 183 procedure Move (Target : in out Map; Source : in out Map); 184 -- Clears Target (if it's not empty), and then moves (not copies) the 185 -- buckets array and nodes from Source to Target. 186 187 procedure Insert 188 (Container : in out Map; 189 Key : Key_Type; 190 New_Item : Element_Type; 191 Position : out Cursor; 192 Inserted : out Boolean); 193 -- Conditionally inserts New_Item into the map. If Key is already in the 194 -- map, then Inserted returns False and Position designates the node 195 -- containing the existing key/element pair (neither of which is modified). 196 -- If Key is not already in the map, the Inserted returns True and Position 197 -- designates the newly-inserted node container Key and New_Item. The 198 -- search for the key works as follows. Hash is called to determine Key's 199 -- bucket; if the bucket is non-empty, then Equivalent_Keys is called to 200 -- compare Key to each node in that bucket. If the bucket is empty, or 201 -- there were no matching keys in the bucket, the search "fails" and the 202 -- key/item pair is inserted in the map (and Inserted returns True); 203 -- otherwise, the search "succeeds" (and Inserted returns False). 204 205 procedure Insert 206 (Container : in out Map; 207 Key : Key_Type; 208 Position : out Cursor; 209 Inserted : out Boolean); 210 -- The same as the (conditional) Insert that accepts an element parameter, 211 -- with the difference that if Inserted returns True, then the element of 212 -- the newly-inserted node is initialized to its default value. 213 214 procedure Insert 215 (Container : in out Map; 216 Key : Key_Type; 217 New_Item : Element_Type); 218 -- Attempts to insert Key into the map, performing the usual search (which 219 -- involves calling both Hash and Equivalent_Keys); if the search succeeds 220 -- (because Key is already in the map), then it raises Constraint_Error. 221 -- (This version of Insert is similar to Replace, but having the opposite 222 -- exception behavior. It is intended for use when you want to assert that 223 -- Key is not already in the map.) 224 225 procedure Include 226 (Container : in out Map; 227 Key : Key_Type; 228 New_Item : Element_Type); 229 -- Attempts to insert Key into the map. If Key is already in the map, then 230 -- both the existing key and element are assigned the values of Key and 231 -- New_Item, respectively. (This version of Insert only raises an exception 232 -- if cursor tampering occurs. It is intended for use when you want to 233 -- insert the key/element pair in the map, and you don't care whether Key 234 -- is already present.) 235 236 procedure Replace 237 (Container : in out Map; 238 Key : Key_Type; 239 New_Item : Element_Type); 240 -- Searches for Key in the map; if the search fails (because Key was not in 241 -- the map), then it raises Constraint_Error. Otherwise, both the existing 242 -- key and element are assigned the values of Key and New_Item rsp. (This 243 -- is similar to Insert, but with the opposite exception behavior. It is to 244 -- be used when you want to assert that Key is already in the map.) 245 246 procedure Exclude (Container : in out Map; Key : Key_Type); 247 -- Searches for Key in the map, and if found, removes its node from the map 248 -- and then deallocates it. The search works as follows. The operation 249 -- calls Hash to determine the key's bucket; if the bucket is not empty, it 250 -- calls Equivalent_Keys to compare Key to each key in the bucket. (This is 251 -- the deletion analog of Include. It is intended for use when you want to 252 -- remove the item from the map, but don't care whether the key is already 253 -- in the map.) 254 255 procedure Delete (Container : in out Map; Key : Key_Type); 256 -- Searches for Key in the map (which involves calling both Hash and 257 -- Equivalent_Keys). If the search fails, then the operation raises 258 -- Constraint_Error. Otherwise it removes the node from the map and then 259 -- deallocates it. (This is the deletion analog of non-conditional 260 -- Insert. It is intended for use when you want to assert that the item is 261 -- already in the map.) 262 263 procedure Delete (Container : in out Map; Position : in out Cursor); 264 -- Removes the node designated by Position from the map, and then 265 -- deallocates the node. The operation calls Hash to determine the bucket, 266 -- and then compares Position to each node in the bucket until there's a 267 -- match (it does not call Equivalent_Keys). 268 269 function First (Container : Map) return Cursor; 270 -- Returns a cursor that designates the first non-empty bucket, by 271 -- searching from the beginning of the buckets array. 272 273 function Next (Position : Cursor) return Cursor; 274 -- Returns a cursor that designates the node that follows the current one 275 -- designated by Position. If Position designates the last node in its 276 -- bucket, the operation calls Hash to compute the index of this bucket, 277 -- and searches the buckets array for the first non-empty bucket, starting 278 -- from that index; otherwise, it simply follows the link to the next node 279 -- in the same bucket. 280 281 procedure Next (Position : in out Cursor); 282 -- Equivalent to Position := Next (Position) 283 284 function Find (Container : Map; Key : Key_Type) return Cursor; 285 -- Searches for Key in the map. Find calls Hash to determine the key's 286 -- bucket; if the bucket is not empty, it calls Equivalent_Keys to compare 287 -- Key to each key in the bucket. If the search succeeds, Find returns a 288 -- cursor designating the matching node; otherwise, it returns No_Element. 289 290 function Contains (Container : Map; Key : Key_Type) return Boolean; 291 -- Equivalent to Find (Container, Key) /= No_Element 292 293 function Element (Container : Map; Key : Key_Type) return Element_Type; 294 -- Equivalent to Element (Find (Container, Key)) 295 296 function Equivalent_Keys (Left, Right : Cursor) return Boolean; 297 -- Returns the result of calling Equivalent_Keys with the keys of the nodes 298 -- designated by cursors Left and Right. 299 300 function Equivalent_Keys (Left : Cursor; Right : Key_Type) return Boolean; 301 -- Returns the result of calling Equivalent_Keys with key of the node 302 -- designated by Left and key Right. 303 304 function Equivalent_Keys (Left : Key_Type; Right : Cursor) return Boolean; 305 -- Returns the result of calling Equivalent_Keys with key Left and the node 306 -- designated by Right. 307 308 procedure Iterate 309 (Container : Map; 310 Process : not null access procedure (Position : Cursor)); 311 -- Calls Process for each node in the map 312 313 function Iterate (Container : Map) 314 return Map_Iterator_Interfaces.Forward_Iterator'class; 315 316private 317 pragma Inline (Length); 318 pragma Inline (Is_Empty); 319 pragma Inline (Clear); 320 pragma Inline (Key); 321 pragma Inline (Element); 322 pragma Inline (Move); 323 pragma Inline (Contains); 324 pragma Inline (Capacity); 325 pragma Inline (Reserve_Capacity); 326 pragma Inline (Has_Element); 327 pragma Inline (Next); 328 329 type Node_Type is record 330 Key : Key_Type; 331 Element : aliased Element_Type; 332 Next : Count_Type; 333 end record; 334 335 package HT_Types is 336 new Hash_Tables.Generic_Bounded_Hash_Table_Types (Node_Type); 337 338 type Map (Capacity : Count_Type; Modulus : Hash_Type) is 339 new HT_Types.Hash_Table_Type (Capacity, Modulus) with null record; 340 341 use HT_Types; 342 use Ada.Streams; 343 use Ada.Finalization; 344 345 procedure Write 346 (Stream : not null access Root_Stream_Type'Class; 347 Container : Map); 348 349 for Map'Write use Write; 350 351 procedure Read 352 (Stream : not null access Root_Stream_Type'Class; 353 Container : out Map); 354 355 for Map'Read use Read; 356 357 type Map_Access is access all Map; 358 for Map_Access'Storage_Size use 0; 359 360 -- Note: If a Cursor object has no explicit initialization expression, 361 -- it must default initialize to the same value as constant No_Element. 362 -- The Node component of type Cursor has scalar type Count_Type, so it 363 -- requires an explicit initialization expression of its own declaration, 364 -- in order for objects of record type Cursor to properly initialize. 365 366 type Cursor is record 367 Container : Map_Access; 368 Node : Count_Type := 0; 369 end record; 370 371 procedure Read 372 (Stream : not null access Root_Stream_Type'Class; 373 Item : out Cursor); 374 375 for Cursor'Read use Read; 376 377 procedure Write 378 (Stream : not null access Root_Stream_Type'Class; 379 Item : Cursor); 380 381 for Cursor'Write use Write; 382 383 type Constant_Reference_Type 384 (Element : not null access constant Element_Type) is null record; 385 386 procedure Write 387 (Stream : not null access Root_Stream_Type'Class; 388 Item : Constant_Reference_Type); 389 390 for Constant_Reference_Type'Write use Write; 391 392 procedure Read 393 (Stream : not null access Root_Stream_Type'Class; 394 Item : out Constant_Reference_Type); 395 396 for Constant_Reference_Type'Read use Read; 397 398 type Reference_Type 399 (Element : not null access Element_Type) is null record; 400 401 procedure Write 402 (Stream : not null access Root_Stream_Type'Class; 403 Item : Reference_Type); 404 405 for Reference_Type'Write use Write; 406 407 procedure Read 408 (Stream : not null access Root_Stream_Type'Class; 409 Item : out Reference_Type); 410 411 for Reference_Type'Read use Read; 412 413 Empty_Map : constant Map := 414 (Hash_Table_Type with Capacity => 0, Modulus => 0); 415 416 No_Element : constant Cursor := (Container => null, Node => 0); 417 type Iterator is new Limited_Controlled and 418 Map_Iterator_Interfaces.Forward_Iterator with 419 record 420 Container : Map_Access; 421 end record; 422 423 overriding procedure Finalize (Object : in out Iterator); 424 425 overriding function First (Object : Iterator) return Cursor; 426 427 overriding function Next 428 (Object : Iterator; 429 Position : Cursor) return Cursor; 430 431end Ada.Containers.Bounded_Hashed_Maps; 432