gcc/ada/libgnat/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) 2004-2017, 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 with Ada.Iterator_Interfaces;
  39
  40 generic
  41    type Element_Type (<>) is private;
  42
  43    with function "<" (Left, Right : Element_Type) return Boolean is <>;
  44    with function "=" (Left, Right : Element_Type) return Boolean is <>;
  45
  46 package Ada.Containers.Indefinite_Ordered_Multisets is
  47    pragma Annotate (CodePeer, Skip_Analysis);
  48    pragma Preelaborate;
  49    pragma Remote_Types;
  50
  51    function Equivalent_Elements (Left, Right : Element_Type) return Boolean;
  52    --  Returns False if Left is less than Right, or Right is less than Left;
  53    --  otherwise, it returns True.
  54
  55    type Set is tagged private
  56    with Constant_Indexing => Constant_Reference,
  57         Default_Iterator  => Iterate,
  58         Iterator_Element  => Element_Type;
  59
  60    pragma Preelaborable_Initialization (Set);
  61
  62    type Cursor is private;
  63    pragma Preelaborable_Initialization (Cursor);
  64
  65    Empty_Set : constant Set;
  66    --  The default value for set objects declared without an explicit
  67    --  initialization expression.
  68
  69    No_Element : constant Cursor;
  70    --  The default value for cursor objects declared without an explicit
  71    --  initialization expression.
  72
  73    function Has_Element (Position : Cursor) return Boolean;
  74    --  Equivalent to Position /= No_Element
  75
  76    package Set_Iterator_Interfaces is new
  77      Ada.Iterator_Interfaces (Cursor, Has_Element);
  78
  79    function "=" (Left, Right : Set) return Boolean;
  80    --  If Left denotes the same set object as Right, then equality returns
  81    --  True. If the length of Left is different from the length of Right, then
  82    --  it returns False. Otherwise, set equality iterates over Left and Right,
  83    --  comparing the element of Left to the element of Right using the equality
  84    --  operator for elements. If the elements compare False, then the iteration
  85    --  terminates and set equality returns False. Otherwise, if all elements
  86    --  compare True, then set equality returns True.
  87
  88    function Equivalent_Sets (Left, Right : Set) return Boolean;
  89    --  Similar to set equality, but with the difference that elements are
  90    --  compared for equivalence instead of equality.
  91
  92    function To_Set (New_Item : Element_Type) return Set;
  93    --  Constructs a set object with New_Item as its single element
  94
  95    function Length (Container : Set) return Count_Type;
  96    --  Returns the total number of elements in Container
  97
  98    function Is_Empty (Container : Set) return Boolean;
  99    --  Returns True if Container.Length is 0
 100
 101    procedure Clear (Container : in out Set);
 102    --  Deletes all elements from Container
 103
 104    function Element (Position : Cursor) return Element_Type;
 105    --  If Position equals No_Element, then Constraint_Error is raised.
 106    --  Otherwise, function Element returns the element designed by Position.
 107
 108    procedure Replace_Element
 109      (Container : in out Set;
 110       Position  : Cursor;
 111       New_Item  : Element_Type);
 112    --  If Position equals No_Element, then Constraint_Error is raised. If
 113    --  Position is associated with a set different from Container, then
 114    --  Program_Error is raised. If New_Item is equivalent to the element
 115    --  designated by Position, then if Container is locked (element tampering
 116    --  has been attempted), Program_Error is raised; otherwise, the element
 117    --  designated by Position is assigned the value of New_Item. If New_Item is
 118    --  not equivalent to the element designated by Position, then if the
 119    --  container is busy (cursor tampering has been attempted), Program_Error
 120    --  is raised; otherwise, the element designed by Position is assigned the
 121    --  value of New_Item, and the node is moved to its new position (in
 122    --  canonical insertion order).
 123
 124    procedure Query_Element
 125      (Position : Cursor;
 126       Process  : not null access procedure (Element : Element_Type));
 127    --  If Position equals No_Element, then Constraint_Error is
 128    --  raised. Otherwise, it calls Process with the element designated by
 129    --  Position as the parameter. This call locks the container, so attempts to
 130    --  change the value of the element while Process is executing (to "tamper
 131    --  with elements") will raise Program_Error.
 132
 133    type Constant_Reference_Type
 134      (Element : not null access constant Element_Type) is private
 135         with Implicit_Dereference => Element;
 136
 137    function Constant_Reference
 138      (Container : aliased Set;
 139       Position  : Cursor) return Constant_Reference_Type;
 140    pragma Inline (Constant_Reference);
 141
 142    procedure Assign (Target : in out Set; Source : Set);
 143
 144    function Copy (Source : Set) return Set;
 145
 146    procedure Move (Target : in out Set; Source : in out Set);
 147    --  If Target denotes the same object as Source, the operation does
 148    --  nothing. If either Target or Source is busy (cursor tampering is
 149    --  attempted), then it raises Program_Error. Otherwise, Target is cleared,
 150    --  and the nodes from Source are moved (not copied) to Target (so Source
 151    --  becomes empty).
 152
 153    procedure Insert
 154      (Container : in out Set;
 155       New_Item  : Element_Type;
 156       Position  : out Cursor);
 157    --  Insert adds New_Item to Container, and returns cursor Position
 158    --  designating the newly inserted node. The node is inserted after any
 159    --  existing elements less than or equivalent to New_Item (and before any
 160    --  elements greater than New_Item). Note that the issue of where the new
 161    --  node is inserted relative to equivalent elements does not arise for
 162    --  unique-key containers, since in that case the insertion would simply
 163    --  fail. For a multiple-key container (the case here), insertion always
 164    --  succeeds, and is defined such that the new item is positioned after any
 165    --  equivalent elements already in the container.
 166
 167    procedure Insert (Container : in out Set; New_Item : Element_Type);
 168    --  Inserts New_Item in Container, but does not return a cursor designating
 169    --  the newly-inserted node.
 170
 171 --  TODO: include Replace too???
 172 --
 173 --     procedure Replace
 174 --       (Container : in out Set;
 175 --        New_Item  : Element_Type);
 176
 177    procedure Exclude (Container : in out Set; Item : Element_Type);
 178    --  Deletes from Container all of the elements equivalent to Item
 179
 180    procedure Delete (Container : in out Set; Item : Element_Type);
 181    --  Deletes from Container all of the elements equivalent to Item. If there
 182    --  are no elements equivalent to Item, then it raises Constraint_Error.
 183
 184    procedure Delete (Container : in out Set; Position : in out Cursor);
 185    --  If Position equals No_Element, then Constraint_Error is raised. If
 186    --  Position is associated with a set different from Container, then
 187    --  Program_Error is raised. Otherwise, the node designated by Position is
 188    --  removed from Container, and Position is set to No_Element.
 189
 190    procedure Delete_First (Container : in out Set);
 191    --  Removes the first node from Container
 192
 193    procedure Delete_Last (Container : in out Set);
 194    --  Removes the last node from Container
 195
 196    procedure Union (Target : in out Set; Source : Set);
 197    --  If Target is busy (cursor tampering is attempted), then Program_Error is
 198    --  raised. Otherwise, it inserts each element of Source into Target.
 199    --  Elements are inserted in the canonical order for multisets, such that
 200    --  the elements from Source are inserted after equivalent elements already
 201    --  in Target.
 202
 203    function Union (Left, Right : Set) return Set;
 204    --  Returns a set comprising the all elements from Left and all of the
 205    --  elements from Right. The elements from Right follow the equivalent
 206    --  elements from Left.
 207
 208    function "or" (Left, Right : Set) return Set renames Union;
 209
 210    procedure Intersection (Target : in out Set; Source : Set);
 211    --  If Target denotes the same object as Source, the operation does
 212    --  nothing. If Target is busy (cursor tampering is attempted),
 213    --  Program_Error is raised. Otherwise, the elements in Target having no
 214    --  equivalent element in Source are deleted from Target.
 215
 216    function Intersection (Left, Right : Set) return Set;
 217    --  If Left denotes the same object as Right, then the function returns a
 218    --  copy of Left. Otherwise, it returns a set comprising the equivalent
 219    --  elements from both Left and Right. Items are inserted in the result set
 220    --  in canonical order, such that the elements from Left precede the
 221    --  equivalent elements from Right.
 222
 223    function "and" (Left, Right : Set) return Set renames Intersection;
 224
 225    procedure Difference (Target : in out Set; Source : Set);
 226    --  If Target is busy (cursor tampering is attempted), then Program_Error is
 227    --  raised. Otherwise, the elements in Target that are equivalent to
 228    --  elements in Source are deleted from Target.
 229
 230    function Difference (Left, Right : Set) return Set;
 231    --  Returns a set comprising the elements from Left that have no equivalent
 232    --  element in Right.
 233
 234    function "-" (Left, Right : Set) return Set renames Difference;
 235
 236    procedure Symmetric_Difference (Target : in out Set; Source : Set);
 237    --  If Target is busy, then Program_Error is raised. Otherwise, the elements
 238    --  in Target equivalent to elements in Source are deleted from Target, and
 239    --  the elements in Source not equivalent to elements in Target are inserted
 240    --  into Target.
 241
 242    function Symmetric_Difference (Left, Right : Set) return Set;
 243    --  Returns a set comprising the union of the elements from Target having no
 244    --  equivalent in Source, and the elements of Source having no equivalent in
 245    --  Target.
 246
 247    function "xor" (Left, Right : Set) return Set renames Symmetric_Difference;
 248
 249    function Overlap (Left, Right : Set) return Boolean;
 250    --  Returns True if Left contains an element equivalent to an element of
 251    --  Right.
 252
 253    function Is_Subset (Subset : Set; Of_Set : Set) return Boolean;
 254    --  Returns True if every element in Subset has an equivalent element in
 255    --  Of_Set.
 256
 257    function First (Container : Set) return Cursor;
 258    --  If Container is empty, the function returns No_Element. Otherwise, it
 259    --  returns a cursor designating the smallest element.
 260
 261    function First_Element (Container : Set) return Element_Type;
 262    --  Equivalent to Element (First (Container))
 263
 264    function Last (Container : Set) return Cursor;
 265    --  If Container is empty, the function returns No_Element. Otherwise, it
 266    --  returns a cursor designating the largest element.
 267
 268    function Last_Element (Container : Set) return Element_Type;
 269    --  Equivalent to Element (Last (Container))
 270
 271    function Next (Position : Cursor) return Cursor;
 272    --  If Position equals No_Element or Last (Container), the function returns
 273    --  No_Element. Otherwise, it returns a cursor designating the node that
 274    --  immediately follows (as per the insertion order) the node designated by
 275    --  Position.
 276
 277    procedure Next (Position : in out Cursor);
 278    --  Equivalent to Position := Next (Position)
 279
 280    function Previous (Position : Cursor) return Cursor;
 281    --  If Position equals No_Element or First (Container), the function returns
 282    --  No_Element. Otherwise, it returns a cursor designating the node that
 283    --  immediately precedes (as per the insertion order) the node designated by
 284    --  Position.
 285
 286    procedure Previous (Position : in out Cursor);
 287    --  Equivalent to Position := Previous (Position)
 288
 289    function Find (Container : Set; Item : Element_Type) return Cursor;
 290    --  Returns a cursor designating the first element in Container equivalent
 291    --  to Item. If there is no equivalent element, it returns No_Element.
 292
 293    function Floor (Container : Set; Item : Element_Type) return Cursor;
 294    --  If Container is empty, the function returns No_Element. If Item is
 295    --  equivalent to elements in Container, it returns a cursor designating the
 296    --  first equivalent element. Otherwise, it returns a cursor designating the
 297    --  largest element less than Item, or No_Element if all elements are
 298    --  greater than Item.
 299
 300    function Ceiling (Container : Set; Item : Element_Type) return Cursor;
 301    --  If Container is empty, the function returns No_Element. If Item is
 302    --  equivalent to elements of Container, it returns a cursor designating the
 303    --  last equivalent element. Otherwise, it returns a cursor designating the
 304    --  smallest element greater than Item, or No_Element if all elements are
 305    --  less than Item.
 306
 307    function Contains (Container : Set; Item : Element_Type) return Boolean;
 308    --  Equivalent to Container.Find (Item) /= No_Element
 309
 310    function "<" (Left, Right : Cursor) return Boolean;
 311    --  Equivalent to Element (Left) < Element (Right)
 312
 313    function ">" (Left, Right : Cursor) return Boolean;
 314    --  Equivalent to Element (Right) < Element (Left)
 315
 316    function "<" (Left : Cursor; Right : Element_Type) return Boolean;
 317    --  Equivalent to Element (Left) < Right
 318
 319    function ">" (Left : Cursor; Right : Element_Type) return Boolean;
 320    --  Equivalent to Right < Element (Left)
 321
 322    function "<" (Left : Element_Type; Right : Cursor) return Boolean;
 323    --  Equivalent to Left < Element (Right)
 324
 325    function ">" (Left : Element_Type; Right : Cursor) return Boolean;
 326    --  Equivalent to Element (Right) < Left
 327
 328    procedure Iterate
 329      (Container : Set;
 330       Process   : not null access procedure (Position : Cursor));
 331    --  Calls Process with a cursor designating each element of Container, in
 332    --  order from Container.First to Container.Last.
 333
 334    procedure Reverse_Iterate
 335      (Container : Set;
 336       Process   : not null access procedure (Position : Cursor));
 337    --  Calls Process with a cursor designating each element of Container, in
 338    --  order from Container.Last to Container.First.
 339
 340    procedure Iterate
 341      (Container : Set;
 342       Item      : Element_Type;
 343       Process   : not null access procedure (Position : Cursor));
 344    --  Call Process with a cursor designating each element equivalent to Item,
 345    --  in order from Container.Floor (Item) to Container.Ceiling (Item).
 346
 347    procedure Reverse_Iterate
 348      (Container : Set;
 349       Item      : Element_Type;
 350       Process   : not null access procedure (Position : Cursor));
 351    --  Call Process with a cursor designating each element equivalent to Item,
 352    --  in order from Container.Ceiling (Item) to Container.Floor (Item).
 353
 354    function Iterate
 355      (Container : Set)
 356       return Set_Iterator_Interfaces.Reversible_Iterator'class;
 357
 358    function Iterate
 359      (Container : Set;
 360       Start     : Cursor)
 361       return Set_Iterator_Interfaces.Reversible_Iterator'class;
 362
 363    generic
 364       type Key_Type (<>) is private;
 365
 366       with function Key (Element : Element_Type) return Key_Type;
 367
 368       with function "<" (Left, Right : Key_Type) return Boolean is <>;
 369
 370    package Generic_Keys is
 371
 372       function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
 373       --  Returns False if Left is less than Right, or Right is less than Left;
 374       --  otherwise, it returns True.
 375
 376       function Key (Position : Cursor) return Key_Type;
 377       --  Equivalent to Key (Element (Position))
 378
 379       function Element (Container : Set; Key : Key_Type) return Element_Type;
 380       --  Equivalent to Element (Find (Container, Key))
 381
 382       procedure Exclude (Container : in out Set; Key : Key_Type);
 383       --  Deletes from Container any elements whose key is equivalent to Key
 384
 385       procedure Delete (Container : in out Set; Key : Key_Type);
 386       --  Deletes from Container any elements whose key is equivalent to
 387       --  Key. If there are no such elements, then it raises Constraint_Error.
 388
 389       function Find (Container : Set; Key : Key_Type) return Cursor;
 390       --  Returns a cursor designating the first element in Container whose key
 391       --  is equivalent to Key. If there is no equivalent element, it returns
 392       --  No_Element.
 393
 394       function Floor (Container : Set; Key : Key_Type) return Cursor;
 395       --  If Container is empty, the function returns No_Element. If Item is
 396       --  equivalent to the keys of elements in Container, it returns a cursor
 397       --  designating the first such element. Otherwise, it returns a cursor
 398       --  designating the largest element whose key is less than Item, or
 399       --  No_Element if all keys are greater than Item.
 400
 401       function Ceiling (Container : Set; Key : Key_Type) return Cursor;
 402       --  If Container is empty, the function returns No_Element. If Item is
 403       --  equivalent to the keys of elements of Container, it returns a cursor
 404       --  designating the last such element. Otherwise, it returns a cursor
 405       --  designating the smallest element whose key is greater than Item, or
 406       --  No_Element if all keys are less than Item.
 407
 408       function Contains (Container : Set; Key : Key_Type) return Boolean;
 409       --  Equivalent to Find (Container, Key) /= No_Element
 410
 411       procedure Update_Element  -- Update_Element_Preserving_Key ???
 412         (Container : in out Set;
 413          Position  : Cursor;
 414          Process   : not null access
 415                        procedure (Element : in out Element_Type));
 416       --  If Position equals No_Element, then Constraint_Error is raised. If
 417       --  Position is associated with a set object different from Container,
 418       --  then Program_Error is raised. Otherwise, it makes a copy of the key
 419       --  of the element designated by Position, and then calls Process with
 420       --  the element as the parameter. Update_Element then compares the key
 421       --  value obtained before calling Process to the key value obtained from
 422       --  the element after calling Process. If the keys are equivalent then
 423       --  the operation terminates. If Container is busy (cursor tampering has
 424       --  been attempted), then Program_Error is raised. Otherwise, the node
 425       --  is moved to its new position (in canonical order).
 426
 427       procedure Iterate
 428         (Container : Set;
 429          Key       : Key_Type;
 430          Process   : not null access procedure (Position : Cursor));
 431       --  Call Process with a cursor designating each element equivalent to
 432       --  Key, in order from Floor (Container, Key) to
 433       --  Ceiling (Container, Key).
 434
 435       procedure Reverse_Iterate
 436         (Container : Set;
 437          Key       : Key_Type;
 438          Process   : not null access procedure (Position : Cursor));
 439       --  Call Process with a cursor designating each element equivalent to
 440       --  Key, in order from Ceiling (Container, Key) to
 441       --  Floor (Container, Key).
 442
 443    end Generic_Keys;
 444
 445 private
 446
 447    pragma Inline (Next);
 448    pragma Inline (Previous);
 449
 450    type Node_Type;
 451    type Node_Access is access Node_Type;
 452
 453    type Element_Access is access Element_Type;
 454
 455    type Node_Type is limited record
 456       Parent  : Node_Access;
 457       Left    : Node_Access;
 458       Right   : Node_Access;
 459       Color   : Red_Black_Trees.Color_Type := Red_Black_Trees.Red;
 460       Element : Element_Access;
 461    end record;
 462
 463    package Tree_Types is new Red_Black_Trees.Generic_Tree_Types
 464      (Node_Type,
 465       Node_Access);
 466
 467    type Set is new Ada.Finalization.Controlled with record
 468       Tree : Tree_Types.Tree_Type;
 469    end record;
 470
 471    overriding procedure Adjust (Container : in out Set);
 472
 473    overriding procedure Finalize (Container : in out Set) renames Clear;
 474
 475    use Red_Black_Trees;
 476    use Tree_Types, Tree_Types.Implementation;
 477    use Ada.Finalization;
 478    use Ada.Streams;
 479
 480    type Set_Access is access all Set;
 481    for Set_Access'Storage_Size use 0;
 482
 483    --  In all predefined libraries the following type is controlled, for proper
 484    --  management of tampering checks. For performance reason we omit this
 485    --  machinery for multisets, which are used in a number of our tools.
 486
 487    type Reference_Control_Type is record
 488       Container : Set_Access;
 489    end record;
 490
 491    type Constant_Reference_Type
 492      (Element : not null access constant Element_Type) is record
 493       Control : Reference_Control_Type :=
 494         raise Program_Error with "uninitialized reference";
 495       --  The RM says, "The default initialization of an object of
 496       --  type Constant_Reference_Type or Reference_Type propagates
 497       --  Program_Error."
 498    end record;
 499
 500    type Cursor is record
 501       Container : Set_Access;
 502       Node      : Node_Access;
 503    end record;
 504
 505    procedure Write
 506      (Stream : not null access Root_Stream_Type'Class;
 507       Item   : Cursor);
 508
 509    for Cursor'Write use Write;
 510
 511    procedure Read
 512      (Stream : not null access Root_Stream_Type'Class;
 513       Item   : out Cursor);
 514
 515    for Cursor'Read use Read;
 516
 517    No_Element : constant Cursor := Cursor'(null, null);
 518
 519    procedure Write
 520      (Stream    : not null access Root_Stream_Type'Class;
 521       Container : Set);
 522
 523    for Set'Write use Write;
 524
 525    procedure Read
 526      (Stream    : not null access Root_Stream_Type'Class;
 527       Container : out Set);
 528
 529    for Set'Read use Read;
 530
 531    procedure Read
 532      (Stream : not null access Root_Stream_Type'Class;
 533       Item   : out Constant_Reference_Type);
 534
 535    for Constant_Reference_Type'Read use Read;
 536
 537    procedure Write
 538      (Stream : not null access Root_Stream_Type'Class;
 539       Item   : Constant_Reference_Type);
 540
 541    for Constant_Reference_Type'Write use Write;
 542
 543    Empty_Set : constant Set := (Controlled with others => <>);
 544
 545    type Iterator is new Limited_Controlled and
 546      Set_Iterator_Interfaces.Reversible_Iterator with
 547    record
 548       Container : Set_Access;
 549       Node      : Node_Access;
 550    end record
 551      with Disable_Controlled => not T_Check;
 552
 553    overriding procedure Finalize (Object : in out Iterator);
 554
 555    overriding function First (Object : Iterator) return Cursor;
 556    overriding function Last  (Object : Iterator) return Cursor;
 557
 558    overriding function Next
 559      (Object   : Iterator;
 560       Position : Cursor) return Cursor;
 561
 562    overriding function Previous
 563      (Object   : Iterator;
 564       Position : Cursor) return Cursor;
 565
 566 end Ada.Containers.Indefinite_Ordered_Multisets;