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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 _ M A P 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_Maps 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 --    contents of a container: Key, Element, Next, Query_Element, Has_Element,
  40 --    Iterate, Equivalent_Keys. This change is motivated by the need to have
  41 --    cursors which are valid on different containers (typically a container C
  42 --    and its previous version C'Old) for expressing properties, which is not
  43 --    possible if cursors encapsulate an access to the underlying container.
  44
  45 --    There are four new functions:
  46
  47 --      function Strict_Equal (Left, Right : Map) return Boolean;
  48 --      function Overlap (Left, Right : Map) return Boolean;
  49 --      function Left  (Container : Map; Position : Cursor) return Map;
  50 --      function Right (Container : Map; Position : Cursor) return Map;
  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 Key_Type is private;
  59    type Element_Type is private;
  60
  61    with function Hash (Key : Key_Type) return Hash_Type;
  62    with function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
  63    with function "=" (Left, Right : Element_Type) return Boolean is <>;
  64
  65 package Ada.Containers.Formal_Hashed_Maps is
  66    pragma Pure;
  67
  68    type Map (Capacity : Count_Type; Modulus : Hash_Type) is tagged private;
  69    pragma Preelaborable_Initialization (Map);
  70
  71    type Cursor is private;
  72    pragma Preelaborable_Initialization (Cursor);
  73
  74    Empty_Map : constant Map;
  75
  76    No_Element : constant Cursor;
  77
  78    function "=" (Left, Right : Map) return Boolean;
  79
  80    function Capacity (Container : Map) return Count_Type;
  81
  82    procedure Reserve_Capacity
  83      (Container : in out Map;
  84       Capacity  : Count_Type);
  85
  86    function Length (Container : Map) return Count_Type;
  87
  88    function Is_Empty (Container : Map) return Boolean;
  89
  90    --  ??? what does clear do to active elements?
  91    procedure Clear (Container : in out Map);
  92
  93    procedure Assign (Target : in out Map; Source : Map);
  94
  95    --  ???
  96    --  capacity=0 means use container.length as cap of tgt
  97    --  modulos=0 means use default_modulous(container.length)
  98    function Copy
  99      (Source   : Map;
 100       Capacity : Count_Type := 0) return Map;
 101
 102    function Key (Container : Map; Position : Cursor) return Key_Type;
 103
 104    function Element (Container : Map; Position : Cursor) return Element_Type;
 105
 106    procedure Replace_Element
 107      (Container : in out Map;
 108       Position  : Cursor;
 109       New_Item  : Element_Type);
 110
 111    procedure Query_Element
 112      (Container : in out Map;
 113       Position  : Cursor;
 114       Process   : not null access
 115                     procedure (Key : Key_Type; Element : Element_Type));
 116
 117    procedure Update_Element
 118      (Container : in out Map;
 119       Position  : Cursor;
 120       Process   : not null access
 121                     procedure (Key : Key_Type; Element : in out Element_Type));
 122
 123    procedure Move (Target : in out Map; Source : in out Map);
 124
 125    procedure Insert
 126      (Container : in out Map;
 127       Key       : Key_Type;
 128       New_Item  : Element_Type;
 129       Position  : out Cursor;
 130       Inserted  : out Boolean);
 131
 132    procedure Insert
 133      (Container : in out Map;
 134       Key       : Key_Type;
 135       Position  : out Cursor;
 136       Inserted  : out Boolean);
 137
 138    procedure Insert
 139      (Container : in out Map;
 140       Key       : Key_Type;
 141       New_Item  : Element_Type);
 142
 143    procedure Include
 144      (Container : in out Map;
 145       Key       : Key_Type;
 146       New_Item  : Element_Type);
 147
 148    procedure Replace
 149      (Container : in out Map;
 150       Key       : Key_Type;
 151       New_Item  : Element_Type);
 152
 153    procedure Exclude (Container : in out Map; Key : Key_Type);
 154
 155    procedure Delete (Container : in out Map; Key : Key_Type);
 156
 157    procedure Delete (Container : in out Map; Position : in out Cursor);
 158
 159    function First (Container : Map) return Cursor;
 160
 161    function Next (Container : Map; Position : Cursor) return Cursor;
 162
 163    procedure Next (Container : Map; Position : in out Cursor);
 164
 165    function Find (Container : Map; Key : Key_Type) return Cursor;
 166
 167    function Contains (Container : Map; Key : Key_Type) return Boolean;
 168
 169    function Element (Container : Map; Key : Key_Type) return Element_Type;
 170
 171    function Has_Element (Container : Map; Position : Cursor) return Boolean;
 172
 173    function Equivalent_Keys
 174      (Left   : Map;
 175       CLeft  : Cursor;
 176       Right  : Map;
 177       CRight : Cursor) return Boolean;
 178
 179    function Equivalent_Keys
 180      (Left  : Map;
 181       CLeft : Cursor;
 182       Right : Key_Type) return Boolean;
 183
 184    function Equivalent_Keys
 185      (Left   : Key_Type;
 186       Right  : Map;
 187       CRight : Cursor) return Boolean;
 188
 189    procedure Iterate
 190      (Container : Map;
 191       Process   : not null access
 192                     procedure (Container : Map; Position : Cursor));
 193
 194    function Default_Modulus (Capacity : Count_Type) return Hash_Type;
 195
 196    function Strict_Equal (Left, Right : Map) return Boolean;
 197    --  Strict_Equal returns True if the containers are physically equal, i.e.
 198    --  they are structurally equal (function "=" returns True) and that they
 199    --  have the same set of cursors.
 200
 201    function Left  (Container : Map; Position : Cursor) return Map;
 202    function Right (Container : Map; Position : Cursor) return Map;
 203    --  Left returns a container containing all elements preceding Position
 204    --  (excluded) in Container. Right returns a container containing all
 205    --  elements following Position (included) in Container. These two new
 206    --  functions can be used to express invariant properties in loops which
 207    --  iterate over containers. Left returns the part of the container already
 208    --  scanned and Right the part not scanned yet.
 209
 210    function Overlap (Left, Right : Map) return Boolean;
 211    --  Overlap returns True if the containers have common keys
 212
 213 private
 214    pragma Inline (Length);
 215    pragma Inline (Is_Empty);
 216    pragma Inline (Clear);
 217    pragma Inline (Key);
 218    pragma Inline (Element);
 219    pragma Inline (Contains);
 220    pragma Inline (Capacity);
 221    pragma Inline (Has_Element);
 222    pragma Inline (Equivalent_Keys);
 223    pragma Inline (Next);
 224
 225    type Node_Type is record
 226       Key         : Key_Type;
 227       Element     : Element_Type;
 228       Next        : Count_Type;
 229       Has_Element : Boolean := False;
 230    end record;
 231
 232    package HT_Types is new
 233      Ada.Containers.Hash_Tables.Generic_Bounded_Hash_Table_Types
 234        (Node_Type);
 235
 236    type Map (Capacity : Count_Type; Modulus : Hash_Type) is
 237       new HT_Types.Hash_Table_Type (Capacity, Modulus) with null record;
 238
 239    use HT_Types;
 240    use Ada.Streams;
 241
 242    procedure Write
 243      (Stream    : not null access Root_Stream_Type'Class;
 244       Container : Map);
 245
 246    for Map'Write use Write;
 247
 248    procedure Read
 249      (Stream    : not null access Root_Stream_Type'Class;
 250       Container : out Map);
 251
 252    for Map'Read use Read;
 253
 254    type Map_Access is access all Map;
 255    for Map_Access'Storage_Size use 0;
 256
 257    type Cursor is record
 258       Node : Count_Type;
 259    end record;
 260
 261    procedure Read
 262      (Stream : not null access Root_Stream_Type'Class;
 263       Item   : out Cursor);
 264
 265    for Cursor'Read use Read;
 266
 267    procedure Write
 268      (Stream : not null access Root_Stream_Type'Class;
 269       Item   : Cursor);
 270
 271    for Cursor'Write use Write;
 272
 273    Empty_Map : constant Map := (Capacity => 0, Modulus => 0, others => <>);
 274
 275    No_Element : constant Cursor := (Node => 0);
 276
 277 end Ada.Containers.Formal_Hashed_Maps;