1------------------------------------------------------------------------------ 2-- -- 3-- GNAT LIBRARY COMPONENTS -- 4-- -- 5-- A D A . C O N T A I N E R S . O R D E R E D _ M U L T I S E T S -- 6-- -- 7-- S p e c -- 8-- -- 9-- Copyright (C) 2004-2011, Free Software Foundation, Inc. -- 10-- -- 11-- GNAT is free software; you can redistribute it and/or modify it under -- 12-- terms of the GNU General Public License as published by the Free Soft- -- 13-- ware Foundation; either version 3, or (at your option) any later ver- -- 14-- sion. GNAT is distributed in the hope that it will be useful, but WITH- -- 15-- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY -- 16-- or FITNESS FOR A PARTICULAR PURPOSE. -- 17-- -- 18-- As a special exception under Section 7 of GPL version 3, you are granted -- 19-- additional permissions described in the GCC Runtime Library Exception, -- 20-- version 3.1, as published by the Free Software Foundation. -- 21-- -- 22-- You should have received a copy of the GNU General Public License and -- 23-- a copy of the GCC Runtime Library Exception along with this program; -- 24-- see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -- 25-- <http://www.gnu.org/licenses/>. -- 26-- -- 27-- This unit was originally developed by Matthew J Heaney. -- 28------------------------------------------------------------------------------ 29 30-- The ordered multiset container is similar to the ordered set, but with the 31-- difference that multiple equivalent elements are allowed. It also provides 32-- additional operations, to iterate over items that are equivalent. 33 34private with Ada.Containers.Red_Black_Trees; 35private with Ada.Finalization; 36private with Ada.Streams; 37with Ada.Iterator_Interfaces; 38 39generic 40 type Element_Type is private; 41 42 with function "<" (Left, Right : Element_Type) return Boolean is <>; 43 with function "=" (Left, Right : Element_Type) return Boolean is <>; 44 45package Ada.Containers.Ordered_Multisets is 46 pragma Preelaborate; 47 pragma Remote_Types; 48 49 function Equivalent_Elements (Left, Right : Element_Type) return Boolean; 50 -- Returns False if Left is less than Right, or Right is less than Left; 51 -- otherwise, it returns True. 52 53 type Set is tagged private 54 with Default_Iterator => Iterate, 55 Iterator_Element => Element_Type; 56 57 pragma Preelaborable_Initialization (Set); 58 59 type Cursor is private; 60 pragma Preelaborable_Initialization (Cursor); 61 62 Empty_Set : constant Set; 63 -- The default value for set objects declared without an explicit 64 -- initialization expression. 65 66 No_Element : constant Cursor; 67 -- The default value for cursor objects declared without an explicit 68 -- initialization expression. 69 70 function Has_Element (Position : Cursor) return Boolean; 71 -- Equivalent to Position /= No_Element 72 73 package Set_Iterator_Interfaces is new 74 Ada.Iterator_Interfaces (Cursor, Has_Element); 75 76 function "=" (Left, Right : Set) return Boolean; 77 -- If Left denotes the same set object as Right, then equality returns 78 -- True. If the length of Left is different from the length of Right, then 79 -- it returns False. Otherwise, set equality iterates over Left and Right, 80 -- comparing the element of Left to the element of Right using the equality 81 -- operator for elements. If the elements compare False, then the iteration 82 -- terminates and set equality returns False. Otherwise, if all elements 83 -- compare True, then set equality returns True. 84 85 function Equivalent_Sets (Left, Right : Set) return Boolean; 86 -- Similar to set equality, but with the difference that elements are 87 -- compared for equivalence instead of equality. 88 89 function To_Set (New_Item : Element_Type) return Set; 90 -- Constructs a set object with New_Item as its single element 91 92 function Length (Container : Set) return Count_Type; 93 -- Returns the total number of elements in Container 94 95 function Is_Empty (Container : Set) return Boolean; 96 -- Returns True if Container.Length is 0 97 98 procedure Clear (Container : in out Set); 99 -- Deletes all elements from Container 100 101 function Element (Position : Cursor) return Element_Type; 102 -- If Position equals No_Element, then Constraint_Error is raised. 103 -- Otherwise, function Element returns the element designed by Position. 104 105 procedure Replace_Element 106 (Container : in out Set; 107 Position : Cursor; 108 New_Item : Element_Type); 109 -- If Position equals No_Element, then Constraint_Error is raised. If 110 -- Position is associated with a set different from Container, then 111 -- Program_Error is raised. If New_Item is equivalent to the element 112 -- designated by Position, then if Container is locked (element tampering 113 -- has been attempted), Program_Error is raised; otherwise, the element 114 -- designated by Position is assigned the value of New_Item. If New_Item is 115 -- not equivalent to the element designated by Position, then if the 116 -- container is busy (cursor tampering has been attempted), Program_Error 117 -- is raised; otherwise, the element designed by Position is assigned the 118 -- value of New_Item, and the node is moved to its new position (in 119 -- canonical insertion order). 120 121 procedure Query_Element 122 (Position : Cursor; 123 Process : not null access procedure (Element : Element_Type)); 124 -- If Position equals No_Element, then Constraint_Error is 125 -- raised. Otherwise, it calls Process with the element designated by 126 -- Position as the parameter. This call locks the container, so attempts to 127 -- change the value of the element while Process is executing (to "tamper 128 -- with elements") will raise Program_Error. 129 130 procedure Assign (Target : in out Set; Source : Set); 131 132 function Copy (Source : Set) return Set; 133 134 procedure Move (Target : in out Set; Source : in out Set); 135 -- If Target denotes the same object as Source, the operation does 136 -- nothing. If either Target or Source is busy (cursor tampering is 137 -- attempted), then it raises Program_Error. Otherwise, Target is cleared, 138 -- and the nodes from Source are moved (not copied) to Target (so Source 139 -- becomes empty). 140 141 procedure Insert 142 (Container : in out Set; 143 New_Item : Element_Type; 144 Position : out Cursor); 145 -- Insert adds New_Item to Container, and returns cursor Position 146 -- designating the newly inserted node. The node is inserted after any 147 -- existing elements less than or equivalent to New_Item (and before any 148 -- elements greater than New_Item). Note that the issue of where the new 149 -- node is inserted relative to equivalent elements does not arise for 150 -- unique-key containers, since in that case the insertion would simply 151 -- fail. For a multiple-key container (the case here), insertion always 152 -- succeeds, and is defined such that the new item is positioned after any 153 -- equivalent elements already in the container. 154 155 procedure Insert 156 (Container : in out Set; 157 New_Item : Element_Type); 158 -- Inserts New_Item in Container, but does not return a cursor designating 159 -- the newly-inserted node. 160 161-- TODO: include Replace too??? 162-- 163-- procedure Replace 164-- (Container : in out Set; 165-- New_Item : Element_Type); 166 167 procedure Exclude 168 (Container : in out Set; 169 Item : Element_Type); 170 -- Deletes from Container all of the elements equivalent to Item 171 172 procedure Delete 173 (Container : in out Set; 174 Item : Element_Type); 175 -- Deletes from Container all of the elements equivalent to Item. If there 176 -- are no elements equivalent to Item, then it raises Constraint_Error. 177 178 procedure Delete 179 (Container : in out Set; 180 Position : in out Cursor); 181 -- If Position equals No_Element, then Constraint_Error is raised. If 182 -- Position is associated with a set different from Container, then 183 -- Program_Error is raised. Otherwise, the node designated by Position is 184 -- removed from Container, and Position is set to No_Element. 185 186 procedure Delete_First (Container : in out Set); 187 -- Removes the first node from Container 188 189 procedure Delete_Last (Container : in out Set); 190 -- Removes the last node from Container 191 192 procedure Union (Target : in out Set; Source : Set); 193 -- If Target is busy (cursor tampering is attempted), the Program_Error is 194 -- raised. Otherwise, it inserts each element of Source into 195 -- Target. Elements are inserted in the canonical order for multisets, such 196 -- that the elements from Source are inserted after equivalent elements 197 -- already in Target. 198 199 function Union (Left, Right : Set) return Set; 200 -- Returns a set comprising the all elements from Left and all of the 201 -- elements from Right. The elements from Right follow the equivalent 202 -- elements from Left. 203 204 function "or" (Left, Right : Set) return Set renames Union; 205 206 procedure Intersection (Target : in out Set; Source : Set); 207 -- If Target denotes the same object as Source, the operation does 208 -- nothing. If Target is busy (cursor tampering is attempted), 209 -- Program_Error is raised. Otherwise, the elements in Target having no 210 -- equivalent element in Source are deleted from Target. 211 212 function Intersection (Left, Right : Set) return Set; 213 -- If Left denotes the same object as Right, then the function returns a 214 -- copy of Left. Otherwise, it returns a set comprising the equivalent 215 -- elements from both Left and Right. Items are inserted in the result set 216 -- in canonical order, such that the elements from Left precede the 217 -- equivalent elements from Right. 218 219 function "and" (Left, Right : Set) return Set renames Intersection; 220 221 procedure Difference (Target : in out Set; Source : Set); 222 -- If Target is busy (cursor tampering is attempted), then Program_Error is 223 -- raised. Otherwise, the elements in Target that are equivalent to 224 -- elements in Source are deleted from Target. 225 226 function Difference (Left, Right : Set) return Set; 227 -- Returns a set comprising the elements from Left that have no equivalent 228 -- element in Right. 229 230 function "-" (Left, Right : Set) return Set renames Difference; 231 232 procedure Symmetric_Difference (Target : in out Set; Source : Set); 233 -- If Target is busy, then Program_Error is raised. Otherwise, the elements 234 -- in Target equivalent to elements in Source are deleted from Target, and 235 -- the elements in Source not equivalent to elements in Target are inserted 236 -- into Target. 237 238 function Symmetric_Difference (Left, Right : Set) return Set; 239 -- Returns a set comprising the union of the elements from Target having no 240 -- equivalent in Source, and the elements of Source having no equivalent in 241 -- Target. 242 243 function "xor" (Left, Right : Set) return Set renames Symmetric_Difference; 244 245 function Overlap (Left, Right : Set) return Boolean; 246 -- Returns True if Left contains an element equivalent to an element of 247 -- Right. 248 249 function Is_Subset (Subset : Set; Of_Set : Set) return Boolean; 250 -- Returns True if every element in Subset has an equivalent element in 251 -- Of_Set. 252 253 function First (Container : Set) return Cursor; 254 -- If Container is empty, the function returns No_Element. Otherwise, it 255 -- returns a cursor designating the smallest element. 256 257 function First_Element (Container : Set) return Element_Type; 258 -- Equivalent to Element (First (Container)) 259 260 function Last (Container : Set) return Cursor; 261 -- If Container is empty, the function returns No_Element. Otherwise, it 262 -- returns a cursor designating the largest element. 263 264 function Last_Element (Container : Set) return Element_Type; 265 -- Equivalent to Element (Last (Container)) 266 267 function Next (Position : Cursor) return Cursor; 268 -- If Position equals No_Element or Last (Container), the function returns 269 -- No_Element. Otherwise, it returns a cursor designating the node that 270 -- immediately follows (as per the insertion order) the node designated by 271 -- Position. 272 273 procedure Next (Position : in out Cursor); 274 -- Equivalent to Position := Next (Position) 275 276 function Previous (Position : Cursor) return Cursor; 277 -- If Position equals No_Element or First (Container), the function returns 278 -- No_Element. Otherwise, it returns a cursor designating the node that 279 -- immediately precedes (as per the insertion order) the node designated by 280 -- Position. 281 282 procedure Previous (Position : in out Cursor); 283 -- Equivalent to Position := Previous (Position) 284 285 function Find (Container : Set; Item : Element_Type) return Cursor; 286 -- Returns a cursor designating the first element in Container equivalent 287 -- to Item. If there is no equivalent element, it returns No_Element. 288 289 function Floor (Container : Set; Item : Element_Type) return Cursor; 290 -- If Container is empty, the function returns No_Element. If Item is 291 -- equivalent to elements in Container, it returns a cursor designating the 292 -- first equivalent element. Otherwise, it returns a cursor designating the 293 -- largest element less than Item, or No_Element if all elements are 294 -- greater than Item. 295 296 function Ceiling (Container : Set; Item : Element_Type) return Cursor; 297 -- If Container is empty, the function returns No_Element. If Item is 298 -- equivalent to elements of Container, it returns a cursor designating the 299 -- last equivalent element. Otherwise, it returns a cursor designating the 300 -- smallest element greater than Item, or No_Element if all elements are 301 -- less than Item. 302 303 function Contains (Container : Set; Item : Element_Type) return Boolean; 304 -- Equivalent to Container.Find (Item) /= No_Element 305 306 function "<" (Left, Right : Cursor) return Boolean; 307 -- Equivalent to Element (Left) < Element (Right) 308 309 function ">" (Left, Right : Cursor) return Boolean; 310 -- Equivalent to Element (Right) < Element (Left) 311 312 function "<" (Left : Cursor; Right : Element_Type) return Boolean; 313 -- Equivalent to Element (Left) < Right 314 315 function ">" (Left : Cursor; Right : Element_Type) return Boolean; 316 -- Equivalent to Right < Element (Left) 317 318 function "<" (Left : Element_Type; Right : Cursor) return Boolean; 319 -- Equivalent to Left < Element (Right) 320 321 function ">" (Left : Element_Type; Right : Cursor) return Boolean; 322 -- Equivalent to Element (Right) < Left 323 324 procedure Iterate 325 (Container : Set; 326 Process : not null access procedure (Position : Cursor)); 327 -- Calls Process with a cursor designating each element of Container, in 328 -- order from Container.First to Container.Last. 329 330 procedure Reverse_Iterate 331 (Container : Set; 332 Process : not null access procedure (Position : Cursor)); 333 -- Calls Process with a cursor designating each element of Container, in 334 -- order from Container.Last to Container.First. 335 336 procedure Iterate 337 (Container : Set; 338 Item : Element_Type; 339 Process : not null access procedure (Position : Cursor)); 340 -- Call Process with a cursor designating each element equivalent to Item, 341 -- in order from Container.Floor (Item) to Container.Ceiling (Item). 342 343 procedure Reverse_Iterate 344 (Container : Set; 345 Item : Element_Type; 346 Process : not null access procedure (Position : Cursor)); 347 -- Call Process with a cursor designating each element equivalent to Item, 348 -- in order from Container.Ceiling (Item) to Container.Floor (Item). 349 350 function Iterate 351 (Container : Set) 352 return Set_Iterator_Interfaces.Reversible_Iterator'class; 353 354 function Iterate 355 (Container : Set; 356 Start : Cursor) 357 return Set_Iterator_Interfaces.Reversible_Iterator'class; 358 359 generic 360 type Key_Type (<>) is private; 361 362 with function Key (Element : Element_Type) return Key_Type; 363 364 with function "<" (Left, Right : Key_Type) return Boolean is <>; 365 366 package Generic_Keys is 367 368 function Equivalent_Keys (Left, Right : Key_Type) return Boolean; 369 -- Returns False if Left is less than Right, or Right is less than Left; 370 -- otherwise, it returns True. 371 372 function Key (Position : Cursor) return Key_Type; 373 -- Equivalent to Key (Element (Position)) 374 375 function Element (Container : Set; Key : Key_Type) return Element_Type; 376 -- Equivalent to Element (Find (Container, Key)) 377 378 procedure Exclude (Container : in out Set; Key : Key_Type); 379 -- Deletes from Container any elements whose key is equivalent to Key 380 381 procedure Delete (Container : in out Set; Key : Key_Type); 382 -- Deletes from Container any elements whose key is equivalent to 383 -- Key. If there are no such elements, then it raises Constraint_Error. 384 385 function Find (Container : Set; Key : Key_Type) return Cursor; 386 -- Returns a cursor designating the first element in Container whose key 387 -- is equivalent to Key. If there is no equivalent element, it returns 388 -- No_Element. 389 390 function Floor (Container : Set; Key : Key_Type) return Cursor; 391 -- If Container is empty, the function returns No_Element. If Item is 392 -- equivalent to the keys of elements in Container, it returns a cursor 393 -- designating the first such element. Otherwise, it returns a cursor 394 -- designating the largest element whose key is less than Item, or 395 -- No_Element if all keys are greater than Item. 396 397 function Ceiling (Container : Set; Key : Key_Type) return Cursor; 398 -- If Container is empty, the function returns No_Element. If Item is 399 -- equivalent to the keys of elements of Container, it returns a cursor 400 -- designating the last such element. Otherwise, it returns a cursor 401 -- designating the smallest element whose key is greater than Item, or 402 -- No_Element if all keys are less than Item. 403 404 function Contains (Container : Set; Key : Key_Type) return Boolean; 405 -- Equivalent to Find (Container, Key) /= No_Element 406 407 procedure Update_Element -- Update_Element_Preserving_Key ??? 408 (Container : in out Set; 409 Position : Cursor; 410 Process : not null access 411 procedure (Element : in out Element_Type)); 412 -- If Position equals No_Element, then Constraint_Error is raised. If 413 -- Position is associated with a set object different from Container, 414 -- then Program_Error is raised. Otherwise, it makes a copy of the key 415 -- of the element designated by Position, and then calls Process with 416 -- the element as the parameter. Update_Element then compares the key 417 -- value obtained before calling Process to the key value obtained from 418 -- the element after calling Process. If the keys are equivalent then 419 -- the operation terminates. If Container is busy (cursor tampering has 420 -- been attempted), then Program_Error is raised. Otherwise, the node 421 -- is moved to its new position (in canonical order). 422 423 procedure Iterate 424 (Container : Set; 425 Key : Key_Type; 426 Process : not null access procedure (Position : Cursor)); 427 -- Call Process with a cursor designating each element equivalent to 428 -- Key, in order from Floor (Container, Key) to 429 -- Ceiling (Container, Key). 430 431 procedure Reverse_Iterate 432 (Container : Set; 433 Key : Key_Type; 434 Process : not null access procedure (Position : Cursor)); 435 -- Call Process with a cursor designating each element equivalent to 436 -- Key, in order from Ceiling (Container, Key) to 437 -- Floor (Container, Key). 438 439 end Generic_Keys; 440 441private 442 443 pragma Inline (Next); 444 pragma Inline (Previous); 445 446 type Node_Type; 447 type Node_Access is access Node_Type; 448 449 type Node_Type is limited record 450 Parent : Node_Access; 451 Left : Node_Access; 452 Right : Node_Access; 453 Color : Red_Black_Trees.Color_Type := Red_Black_Trees.Red; 454 Element : Element_Type; 455 end record; 456 457 package Tree_Types is 458 new Red_Black_Trees.Generic_Tree_Types (Node_Type, Node_Access); 459 460 type Set is new Ada.Finalization.Controlled with record 461 Tree : Tree_Types.Tree_Type; 462 end record; 463 464 overriding procedure Adjust (Container : in out Set); 465 466 overriding procedure Finalize (Container : in out Set) renames Clear; 467 468 use Red_Black_Trees; 469 use Tree_Types; 470 use Ada.Finalization; 471 use Ada.Streams; 472 473 type Set_Access is access all Set; 474 for Set_Access'Storage_Size use 0; 475 476 type Cursor is record 477 Container : Set_Access; 478 Node : Node_Access; 479 end record; 480 481 procedure Write 482 (Stream : not null access Root_Stream_Type'Class; 483 Item : Cursor); 484 485 for Cursor'Write use Write; 486 487 procedure Read 488 (Stream : not null access Root_Stream_Type'Class; 489 Item : out Cursor); 490 491 for Cursor'Read use Read; 492 493 No_Element : constant Cursor := Cursor'(null, null); 494 495 procedure Write 496 (Stream : not null access Root_Stream_Type'Class; 497 Container : Set); 498 499 for Set'Write use Write; 500 501 procedure Read 502 (Stream : not null access Root_Stream_Type'Class; 503 Container : out Set); 504 505 for Set'Read use Read; 506 507 Empty_Set : constant Set := 508 (Controlled with Tree => (First => null, 509 Last => null, 510 Root => null, 511 Length => 0, 512 Busy => 0, 513 Lock => 0)); 514 515end Ada.Containers.Ordered_Multisets; 516