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   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT LIBRARY COMPONENTS                          --
   4 --                                                                          --
   5 --    A D A . C O N T A I N E R S . F O R M A L _ H A S H E D _ S E T S     --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2004-2011, 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
  32 --  This spec is derived from package Ada.Containers.Bounded_Hashed_Sets in the
  33 --  Ada 2012 RM. The modifications are to facilitate formal proofs by making it
  34 --  easier to express properties.
  35
  36 --  The modifications are:
  37
  38 --    A parameter for the container is added to every function reading the
  39 --    content of a container: Element, Next, Query_Element, Has_Element, Key,
  40 --    Iterate, Equivalent_Elements. This change is motivated by the need to
  41 --    have cursors which are valid on different containers (typically a
  42 --    container C and its previous version C'Old) for expressing properties,
  43 --    which is not possible if cursors encapsulate an access to the underlying
  44 --    container.
  45
  46 --    There are three new functions:
  47
  48 --      function Strict_Equal (Left, Right : Set) return Boolean;
  49 --      function Left  (Container : Set; Position : Cursor) return Set;
  50 --      function Right (Container : Set; Position : Cursor) return Set;
  51
  52 --    See detailed specifications for these subprograms
  53
  54 private with Ada.Containers.Hash_Tables;
  55 private with Ada.Streams;
  56
  57 generic
  58    type Element_Type is private;
  59
  60    with function Hash (Element : Element_Type) return Hash_Type;
  61
  62    with function Equivalent_Elements (Left, Right : Element_Type)
  63                                       return Boolean;
  64
  65    with function "=" (Left, Right : Element_Type) return Boolean is <>;
  66
  67 package Ada.Containers.Formal_Hashed_Sets is
  68    pragma Pure;
  69
  70    type Set (Capacity : Count_Type; Modulus : Hash_Type) is tagged private;
  71    --  why is this commented out ???
  72    --  pragma Preelaborable_Initialization (Set);
  73
  74    type Cursor is private;
  75    pragma Preelaborable_Initialization (Cursor);
  76
  77    Empty_Set : constant Set;
  78
  79    No_Element : constant Cursor;
  80
  81    function "=" (Left, Right : Set) return Boolean;
  82
  83    function Equivalent_Sets (Left, Right : Set) return Boolean;
  84
  85    function To_Set (New_Item : Element_Type) return Set;
  86
  87    function Capacity (Container : Set) return Count_Type;
  88
  89    procedure Reserve_Capacity
  90      (Container : in out Set;
  91       Capacity  : Count_Type);
  92
  93    function Length (Container : Set) return Count_Type;
  94
  95    function Is_Empty (Container : Set) return Boolean;
  96
  97    procedure Clear (Container : in out Set);
  98
  99    procedure Assign (Target : in out Set; Source : Set);
 100
 101    function Copy (Source   : Set;
 102                   Capacity : Count_Type := 0) return Set;
 103
 104    function Element (Container : Set; Position : Cursor) return Element_Type;
 105
 106    procedure Replace_Element
 107      (Container : in out Set;
 108       Position  : Cursor;
 109       New_Item  : Element_Type);
 110
 111    procedure Query_Element
 112      (Container : in out Set;
 113       Position  : Cursor;
 114       Process   : not null access procedure (Element : Element_Type));
 115
 116    procedure Move (Target : in out Set; Source : in out Set);
 117
 118    procedure Insert
 119      (Container : in out Set;
 120       New_Item  : Element_Type;
 121       Position  : out Cursor;
 122       Inserted  : out Boolean);
 123
 124    procedure Insert  (Container : in out Set; New_Item : Element_Type);
 125
 126    procedure Include (Container : in out Set; New_Item : Element_Type);
 127
 128    procedure Replace (Container : in out Set; New_Item : Element_Type);
 129
 130    procedure Exclude (Container : in out Set; Item     : Element_Type);
 131
 132    procedure Delete  (Container : in out Set; Item     : Element_Type);
 133
 134    procedure Delete (Container : in out Set; Position  : in out Cursor);
 135
 136    procedure Union (Target : in out Set; Source : Set);
 137
 138    function Union (Left, Right : Set) return Set;
 139
 140    function "or" (Left, Right : Set) return Set renames Union;
 141
 142    procedure Intersection (Target : in out Set; Source : Set);
 143
 144    function Intersection (Left, Right : Set) return Set;
 145
 146    function "and" (Left, Right : Set) return Set renames Intersection;
 147
 148    procedure Difference (Target : in out Set; Source : Set);
 149
 150    function Difference (Left, Right : Set) return Set;
 151
 152    function "-" (Left, Right : Set) return Set renames Difference;
 153
 154    procedure Symmetric_Difference (Target : in out Set; Source : Set);
 155
 156    function Symmetric_Difference (Left, Right : Set) return Set;
 157
 158    function "xor" (Left, Right : Set) return Set
 159                    renames Symmetric_Difference;
 160
 161    function Overlap (Left, Right : Set) return Boolean;
 162
 163    function Is_Subset (Subset : Set; Of_Set : Set) return Boolean;
 164
 165    function First (Container : Set) return Cursor;
 166
 167    function Next (Container : Set; Position : Cursor) return Cursor;
 168
 169    procedure Next (Container : Set; Position : in out Cursor);
 170
 171    function Find
 172      (Container : Set;
 173       Item      : Element_Type) return Cursor;
 174
 175    function Contains (Container : Set; Item : Element_Type) return Boolean;
 176
 177    function Has_Element (Container : Set; Position : Cursor) return Boolean;
 178
 179    function Equivalent_Elements (Left  : Set; CLeft : Cursor;
 180                                  Right : Set; CRight : Cursor) return Boolean;
 181
 182    function Equivalent_Elements
 183      (Left  : Set; CLeft : Cursor;
 184       Right : Element_Type) return Boolean;
 185
 186    function Equivalent_Elements
 187      (Left  : Element_Type;
 188       Right : Set; CRight : Cursor) return Boolean;
 189
 190    procedure Iterate
 191      (Container : Set;
 192       Process   :
 193         not null access procedure (Container : Set; Position : Cursor));
 194
 195    function Default_Modulus (Capacity : Count_Type) return Hash_Type;
 196
 197    generic
 198       type Key_Type (<>) is private;
 199
 200       with function Key (Element : Element_Type) return Key_Type;
 201
 202       with function Hash (Key : Key_Type) return Hash_Type;
 203
 204       with function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
 205
 206    package Generic_Keys is
 207
 208       function Key (Container : Set; Position : Cursor) return Key_Type;
 209
 210       function Element (Container : Set; Key : Key_Type) return Element_Type;
 211
 212       procedure Replace
 213         (Container : in out Set;
 214          Key       : Key_Type;
 215          New_Item  : Element_Type);
 216
 217       procedure Exclude (Container : in out Set; Key : Key_Type);
 218
 219       procedure Delete (Container : in out Set; Key : Key_Type);
 220
 221       function Find (Container : Set; Key : Key_Type) return Cursor;
 222
 223       function Contains (Container : Set; Key : Key_Type) return Boolean;
 224
 225       procedure Update_Element_Preserving_Key
 226         (Container : in out Set;
 227          Position  : Cursor;
 228          Process   : not null access
 229                        procedure (Element : in out Element_Type));
 230
 231    end Generic_Keys;
 232
 233    function Strict_Equal (Left, Right : Set) return Boolean;
 234    --  Strict_Equal returns True if the containers are physically equal, i.e.
 235    --  they are structurally equal (function "=" returns True) and that they
 236    --  have the same set of cursors.
 237
 238    function Left  (Container : Set; Position : Cursor) return Set;
 239    function Right (Container : Set; Position : Cursor) return Set;
 240    --  Left returns a container containing all elements preceding Position
 241    --  (excluded) in Container. Right returns a container containing all
 242    --  elements following Position (included) in Container. These two new
 243    --  functions can be used to express invariant properties in loops which
 244    --  iterate over containers. Left returns the part of the container already
 245    --  scanned and Right the part not scanned yet.
 246
 247 private
 248
 249    pragma Inline (Next);
 250
 251    type Node_Type is
 252       record
 253          Element     : Element_Type;
 254          Next        : Count_Type;
 255          Has_Element : Boolean := False;
 256       end record;
 257
 258    package HT_Types is new
 259      Ada.Containers.Hash_Tables.Generic_Bounded_Hash_Table_Types (Node_Type);
 260
 261    type Set (Capacity : Count_Type; Modulus : Hash_Type) is
 262       new HT_Types.Hash_Table_Type (Capacity, Modulus) with null record;
 263
 264    use HT_Types;
 265    use Ada.Streams;
 266
 267    type Cursor is record
 268       Node : Count_Type;
 269    end record;
 270
 271    procedure Write
 272      (Stream : not null access Root_Stream_Type'Class;
 273       Item   : Cursor);
 274
 275    for Cursor'Write use Write;
 276
 277    procedure Read
 278      (Stream : not null access Root_Stream_Type'Class;
 279       Item   : out Cursor);
 280
 281    for Cursor'Read use Read;
 282
 283    No_Element : constant Cursor := (Node => 0);
 284
 285    procedure Write
 286      (Stream    : not null access Root_Stream_Type'Class;
 287       Container : Set);
 288
 289    for Set'Write use Write;
 290
 291    procedure Read
 292      (Stream    : not null access Root_Stream_Type'Class;
 293       Container : out Set);
 294
 295    for Set'Read use Read;
 296
 297    Empty_Set : constant Set := (Capacity => 0, Modulus => 0, others => <>);
 298
 299 end Ada.Containers.Formal_Hashed_Sets;