gcc/ada/a-ciormu.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT LIBRARY COMPONENTS                          --
   4 --                                                                          --
   5 --               ADA.CONTAINERS.INDEFINITE_ORDERED_MULTISETS                --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2004-2009, 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 indefinite ordered multiset container is similar to the indefinite
  31 --  ordered set, but with the difference that multiple equivalent elements are
  32 --  allowed. It also provides additional operations, to iterate over items that
  33 --  are equivalent.
  34
  35 private with Ada.Containers.Red_Black_Trees;
  36 private with Ada.Finalization;
  37 private with Ada.Streams;
  38
  39 generic
  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
  45 package Ada.Containers.Indefinite_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    pragma Preelaborable_Initialization (Set);
  55
  56    type Cursor is private;
  57    pragma Preelaborable_Initialization (Cursor);
  58
  59    Empty_Set : constant Set;
  60    --  The default value for set objects declared without an explicit
  61    --  initialization expression.
  62
  63    No_Element : constant Cursor;
  64    --  The default value for cursor objects declared without an explicit
  65    --  initialization expression.
  66
  67    function "=" (Left, Right : Set) return Boolean;
  68    --  If Left denotes the same set object as Right, then equality returns
  69    --  True. If the length of Left is different from the length of Right, then
  70    --  it returns False. Otherwise, set equality iterates over Left and Right,
  71    --  comparing the element of Left to the element of Right using the equality
  72    --  operator for elements. If the elements compare False, then the iteration
  73    --  terminates and set equality returns False. Otherwise, if all elements
  74    --  compare True, then set equality returns True.
  75
  76    function Equivalent_Sets (Left, Right : Set) return Boolean;
  77    --  Similar to set equality, but with the difference that elements are
  78    --  compared for equivalence instead of equality.
  79
  80    function To_Set (New_Item : Element_Type) return Set;
  81    --  Constructs a set object with New_Item as its single element
  82
  83    function Length (Container : Set) return Count_Type;
  84    --  Returns the total number of elements in Container
  85
  86    function Is_Empty (Container : Set) return Boolean;
  87    --  Returns True if Container.Length is 0
  88
  89    procedure Clear (Container : in out Set);
  90    --  Deletes all elements from Container
  91
  92    function Element (Position : Cursor) return Element_Type;
  93    --  If Position equals No_Element, then Constraint_Error is raised.
  94    --  Otherwise, function Element returns the element designed by Position.
  95
  96    procedure Replace_Element
  97      (Container : in out Set;
  98       Position  : Cursor;
  99       New_Item  : Element_Type);
 100    --  If Position equals No_Element, then Constraint_Error is raised. If
 101    --  Position is associated with a set different from Container, then
 102    --  Program_Error is raised. If New_Item is equivalent to the element
 103    --  designated by Position, then if Container is locked (element tampering
 104    --  has been attempted), Program_Error is raised; otherwise, the element
 105    --  designated by Position is assigned the value of New_Item. If New_Item is
 106    --  not equivalent to the element designated by Position, then if the
 107    --  container is busy (cursor tampering has been attempted), Program_Error
 108    --  is raised; otherwise, the element designed by Position is assigned the
 109    --  value of New_Item, and the node is moved to its new position (in
 110    --  canonical insertion order).
 111
 112    procedure Query_Element
 113      (Position : Cursor;
 114       Process  : not null access procedure (Element : Element_Type));
 115    --  If Position equals No_Element, then Constraint_Error is
 116    --  raised. Otherwise, it calls Process with the element designated by
 117    --  Position as the parameter. This call locks the container, so attempts to
 118    --  change the value of the element while Process is executing (to "tamper
 119    --  with elements") will raise Program_Error.
 120
 121    procedure Move (Target : in out Set; Source : in out Set);
 122    --  If Target denotes the same object as Source, the operation does
 123    --  nothing. If either Target or Source is busy (cursor tampering is
 124    --  attempted), then it raises Program_Error. Otherwise, Target is cleared,
 125    --  and the nodes from Source are moved (not copied) to Target (so Source
 126    --  becomes empty).
 127
 128    procedure Insert
 129      (Container : in out Set;
 130       New_Item  : Element_Type;
 131       Position  : out Cursor);
 132    --  Insert adds New_Item to Container, and returns cursor Position
 133    --  designating the newly inserted node. The node is inserted after any
 134    --  existing elements less than or equivalent to New_Item (and before any
 135    --  elements greater than New_Item). Note that the issue of where the new
 136    --  node is inserted relative to equivalent elements does not arise for
 137    --  unique-key containers, since in that case the insertion would simply
 138    --  fail. For a multiple-key container (the case here), insertion always
 139    --  succeeds, and is defined such that the new item is positioned after any
 140    --  equivalent elements already in the container.
 141
 142    procedure Insert (Container : in out Set; New_Item : Element_Type);
 143    --  Inserts New_Item in Container, but does not return a cursor designating
 144    --  the newly-inserted node.
 145
 146 --  TODO: include Replace too???
 147 --
 148 --     procedure Replace
 149 --       (Container : in out Set;
 150 --        New_Item  : Element_Type);
 151
 152    procedure Exclude (Container : in out Set; Item : Element_Type);
 153    --  Deletes from Container all of the elements equivalent to Item
 154
 155    procedure Delete (Container : in out Set; Item : Element_Type);
 156    --  Deletes from Container all of the elements equivalent to Item. If there
 157    --  are no elements equivalent to Item, then it raises Constraint_Error.
 158
 159    procedure Delete (Container : in out Set; Position : in out Cursor);
 160    --  If Position equals No_Element, then Constraint_Error is raised. If
 161    --  Position is associated with a set different from Container, then
 162    --  Program_Error is raised. Otherwise, the node designated by Position is
 163    --  removed from Container, and Position is set to No_Element.
 164
 165    procedure Delete_First (Container : in out Set);
 166    --  Removes the first node from Container
 167
 168    procedure Delete_Last (Container : in out Set);
 169    --  Removes the last node from Container
 170
 171    procedure Union (Target : in out Set; Source : Set);
 172    --  If Target is busy (cursor tampering is attempted), then Program_Error is
 173    --  raised. Otherwise, it inserts each element of Source into Target.
 174    --  Elements are inserted in the canonical order for multisets, such that
 175    --  the elements from Source are inserted after equivalent elements already
 176    --  in Target.
 177
 178    function Union (Left, Right : Set) return Set;
 179    --  Returns a set comprising the all elements from Left and all of the
 180    --  elements from Right. The elements from Right follow the equivalent
 181    --  elements from Left.
 182
 183    function "or" (Left, Right : Set) return Set renames Union;
 184
 185    procedure Intersection (Target : in out Set; Source : Set);
 186    --  If Target denotes the same object as Source, the operation does
 187    --  nothing. If Target is busy (cursor tampering is attempted),
 188    --  Program_Error is raised. Otherwise, the elements in Target having no
 189    --  equivalent element in Source are deleted from Target.
 190
 191    function Intersection (Left, Right : Set) return Set;
 192    --  If Left denotes the same object as Right, then the function returns a
 193    --  copy of Left. Otherwise, it returns a set comprising the equivalent
 194    --  elements from both Left and Right. Items are inserted in the result set
 195    --  in canonical order, such that the elements from Left precede the
 196    --  equivalent elements from Right.
 197
 198    function "and" (Left, Right : Set) return Set renames Intersection;
 199
 200    procedure Difference (Target : in out Set; Source : Set);
 201    --  If Target is busy (cursor tampering is attempted), then Program_Error is
 202    --  raised. Otherwise, the elements in Target that are equivalent to
 203    --  elements in Source are deleted from Target.
 204
 205    function Difference (Left, Right : Set) return Set;
 206    --  Returns a set comprising the elements from Left that have no equivalent
 207    --  element in Right.
 208
 209    function "-" (Left, Right : Set) return Set renames Difference;
 210
 211    procedure Symmetric_Difference (Target : in out Set; Source : Set);
 212    --  If Target is busy, then Program_Error is raised. Otherwise, the elements
 213    --  in Target equivalent to elements in Source are deleted from Target, and
 214    --  the elements in Source not equivalent to elements in Target are inserted
 215    --  into Target.
 216
 217    function Symmetric_Difference (Left, Right : Set) return Set;
 218    --  Returns a set comprising the union of the elements from Target having no
 219    --  equivalent in Source, and the elements of Source having no equivalent in
 220    --  Target.
 221
 222    function "xor" (Left, Right : Set) return Set renames Symmetric_Difference;
 223
 224    function Overlap (Left, Right : Set) return Boolean;
 225    --  Returns True if Left contains an element equivalent to an element of
 226    --  Right.
 227
 228    function Is_Subset (Subset : Set; Of_Set : Set) return Boolean;
 229    --  Returns True if every element in Subset has an equivalent element in
 230    --  Of_Set.
 231
 232    function First (Container : Set) return Cursor;
 233    --  If Container is empty, the function returns No_Element. Otherwise, it
 234    --  returns a cursor designating the smallest element.
 235
 236    function First_Element (Container : Set) return Element_Type;
 237    --  Equivalent to Element (First (Container))
 238
 239    function Last (Container : Set) return Cursor;
 240    --  If Container is empty, the function returns No_Element. Otherwise, it
 241    --  returns a cursor designating the largest element.
 242
 243    function Last_Element (Container : Set) return Element_Type;
 244    --  Equivalent to Element (Last (Container))
 245
 246    function Next (Position : Cursor) return Cursor;
 247    --  If Position equals No_Element or Last (Container), the function returns
 248    --  No_Element. Otherwise, it returns a cursor designating the node that
 249    --  immediately follows (as per the insertion order) the node designated by
 250    --  Position.
 251
 252    procedure Next (Position : in out Cursor);
 253    --  Equivalent to Position := Next (Position)
 254
 255    function Previous (Position : Cursor) return Cursor;
 256    --  If Position equals No_Element or First (Container), the function returns
 257    --  No_Element. Otherwise, it returns a cursor designating the node that
 258    --  immediately precedes (as per the insertion order) the node designated by
 259    --  Position.
 260
 261    procedure Previous (Position : in out Cursor);
 262    --  Equivalent to Position := Previous (Position)
 263
 264    function Find (Container : Set; Item : Element_Type) return Cursor;
 265    --  Returns a cursor designating the first element in Container equivalent
 266    --  to Item. If there is no equivalent element, it returns No_Element.
 267
 268    function Floor (Container : Set; Item : Element_Type) return Cursor;
 269    --  If Container is empty, the function returns No_Element. If Item is
 270    --  equivalent to elements in Container, it returns a cursor designating the
 271    --  first equivalent element. Otherwise, it returns a cursor designating the
 272    --  largest element less than Item, or No_Element if all elements are
 273    --  greater than Item.
 274
 275    function Ceiling (Container : Set; Item : Element_Type) return Cursor;
 276    --  If Container is empty, the function returns No_Element. If Item is
 277    --  equivalent to elements of Container, it returns a cursor designating the
 278    --  last equivalent element. Otherwise, it returns a cursor designating the
 279    --  smallest element greater than Item, or No_Element if all elements are
 280    --  less than Item.
 281
 282    function Contains (Container : Set; Item : Element_Type) return Boolean;
 283    --  Equivalent to Container.Find (Item) /= No_Element
 284
 285    function Has_Element (Position : Cursor) return Boolean;
 286    --  Equivalent to Position /= No_Element
 287
 288    function "<" (Left, Right : Cursor) return Boolean;
 289    --  Equivalent to Element (Left) < Element (Right)
 290
 291    function ">" (Left, Right : Cursor) return Boolean;
 292    --  Equivalent to Element (Right) < Element (Left)
 293
 294    function "<" (Left : Cursor; Right : Element_Type) return Boolean;
 295    --  Equivalent to Element (Left) < Right
 296
 297    function ">" (Left : Cursor; Right : Element_Type) return Boolean;
 298    --  Equivalent to Right < Element (Left)
 299
 300    function "<" (Left : Element_Type; Right : Cursor) return Boolean;
 301    --  Equivalent to Left < Element (Right)
 302
 303    function ">" (Left : Element_Type; Right : Cursor) return Boolean;
 304    --  Equivalent to Element (Right) < Left
 305
 306    procedure Iterate
 307      (Container : Set;
 308       Process   : not null access procedure (Position : Cursor));
 309    --  Calls Process with a cursor designating each element of Container, in
 310    --  order from Container.First to Container.Last.
 311
 312    procedure Reverse_Iterate
 313      (Container : Set;
 314       Process   : not null access procedure (Position : Cursor));
 315    --  Calls Process with a cursor designating each element of Container, in
 316    --  order from Container.Last to Container.First.
 317
 318    procedure Iterate
 319      (Container : Set;
 320       Item      : Element_Type;
 321       Process   : not null access procedure (Position : Cursor));
 322    --  Call Process with a cursor designating each element equivalent to Item,
 323    --  in order from Container.Floor (Item) to Container.Ceiling (Item).
 324
 325    procedure Reverse_Iterate
 326      (Container : Set;
 327       Item      : Element_Type;
 328       Process   : not null access procedure (Position : Cursor));
 329    --  Call Process with a cursor designating each element equivalent to Item,
 330    --  in order from Container.Ceiling (Item) to Container.Floor (Item).
 331
 332    generic
 333       type Key_Type (<>) is private;
 334
 335       with function Key (Element : Element_Type) return Key_Type;
 336
 337       with function "<" (Left, Right : Key_Type) return Boolean is <>;
 338
 339    package Generic_Keys is
 340
 341       function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
 342       --  Returns False if Left is less than Right, or Right is less than Left;
 343       --  otherwise, it returns True.
 344
 345       function Key (Position : Cursor) return Key_Type;
 346       --  Equivalent to Key (Element (Position))
 347
 348       function Element (Container : Set; Key : Key_Type) return Element_Type;
 349       --  Equivalent to Element (Find (Container, Key))
 350
 351       procedure Exclude (Container : in out Set; Key : Key_Type);
 352       --  Deletes from Container any elements whose key is equivalent to Key
 353
 354       procedure Delete (Container : in out Set; Key : Key_Type);
 355       --  Deletes from Container any elements whose key is equivalent to
 356       --  Key. If there are no such elements, then it raises Constraint_Error.
 357
 358       function Find (Container : Set; Key : Key_Type) return Cursor;
 359       --  Returns a cursor designating the first element in Container whose key
 360       --  is equivalent to Key. If there is no equivalent element, it returns
 361       --  No_Element.
 362
 363       function Floor (Container : Set; Key : Key_Type) return Cursor;
 364       --  If Container is empty, the function returns No_Element. If Item is
 365       --  equivalent to the keys of elements in Container, it returns a cursor
 366       --  designating the first such element. Otherwise, it returns a cursor
 367       --  designating the largest element whose key is less than Item, or
 368       --  No_Element if all keys are greater than Item.
 369
 370       function Ceiling (Container : Set; Key : Key_Type) return Cursor;
 371       --  If Container is empty, the function returns No_Element. If Item is
 372       --  equivalent to the keys of elements of Container, it returns a cursor
 373       --  designating the last such element. Otherwise, it returns a cursor
 374       --  designating the smallest element whose key is greater than Item, or
 375       --  No_Element if all keys are less than Item.
 376
 377       function Contains (Container : Set; Key : Key_Type) return Boolean;
 378       --  Equivalent to Find (Container, Key) /= No_Element
 379
 380       procedure Update_Element  -- Update_Element_Preserving_Key ???
 381         (Container : in out Set;
 382          Position  : Cursor;
 383          Process   : not null access
 384                        procedure (Element : in out Element_Type));
 385       --  If Position equals No_Element, then Constraint_Error is raised. If
 386       --  Position is associated with a set object different from Container,
 387       --  then Program_Error is raised. Otherwise, it makes a copy of the key
 388       --  of the element designated by Position, and then calls Process with
 389       --  the element as the parameter. Update_Element then compares the key
 390       --  value obtained before calling Process to the key value obtained from
 391       --  the element after calling Process. If the keys are equivalent then
 392       --  the operation terminates. If Container is busy (cursor tampering has
 393       --  been attempted), then Program_Error is raised. Otherwise, the node
 394       --  is moved to its new position (in canonical order).
 395
 396       procedure Iterate
 397         (Container : Set;
 398          Key       : Key_Type;
 399          Process   : not null access procedure (Position : Cursor));
 400       --  Call Process with a cursor designating each element equivalent to
 401       --  Key, in order from Floor (Container, Key) to
 402       --  Ceiling (Container, Key).
 403
 404       procedure Reverse_Iterate
 405         (Container : Set;
 406          Key       : Key_Type;
 407          Process   : not null access procedure (Position : Cursor));
 408       --  Call Process with a cursor designating each element equivalent to
 409       --  Key, in order from Ceiling (Container, Key) to
 410       --  Floor (Container, Key).
 411
 412    end Generic_Keys;
 413
 414 private
 415
 416    pragma Inline (Next);
 417    pragma Inline (Previous);
 418
 419    type Node_Type;
 420    type Node_Access is access Node_Type;
 421
 422    type Element_Access is access Element_Type;
 423
 424    type Node_Type is limited record
 425       Parent  : Node_Access;
 426       Left    : Node_Access;
 427       Right   : Node_Access;
 428       Color   : Red_Black_Trees.Color_Type := Red_Black_Trees.Red;
 429       Element : Element_Access;
 430    end record;
 431
 432    package Tree_Types is new Red_Black_Trees.Generic_Tree_Types
 433      (Node_Type,
 434       Node_Access);
 435
 436    type Set is new Ada.Finalization.Controlled with record
 437       Tree : Tree_Types.Tree_Type;
 438    end record;
 439
 440    overriding
 441    procedure Adjust (Container : in out Set);
 442
 443    overriding
 444    procedure Finalize (Container : in out Set) renames Clear;
 445
 446    use Red_Black_Trees;
 447    use Tree_Types;
 448    use Ada.Finalization;
 449    use Ada.Streams;
 450
 451    type Set_Access is access all Set;
 452    for Set_Access'Storage_Size use 0;
 453
 454    type Cursor is record
 455       Container : Set_Access;
 456       Node      : Node_Access;
 457    end record;
 458
 459    procedure Write
 460      (Stream : not null access Root_Stream_Type'Class;
 461       Item   : Cursor);
 462
 463    for Cursor'Write use Write;
 464
 465    procedure Read
 466      (Stream : not null access Root_Stream_Type'Class;
 467       Item   : out Cursor);
 468
 469    for Cursor'Read use Read;
 470
 471    No_Element : constant Cursor := Cursor'(null, null);
 472
 473    procedure Write
 474      (Stream    : not null access Root_Stream_Type'Class;
 475       Container : Set);
 476
 477    for Set'Write use Write;
 478
 479    procedure Read
 480      (Stream    : not null access Root_Stream_Type'Class;
 481       Container : out Set);
 482
 483    for Set'Read use Read;
 484
 485    Empty_Set : constant Set :=
 486                  (Controlled with Tree => (First  => null,
 487                                            Last   => null,
 488                                            Root   => null,
 489                                            Length => 0,
 490                                            Busy   => 0,
 491                                            Lock   => 0));
 492
 493 end Ada.Containers.Indefinite_Ordered_Multisets;