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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 _ O R D E R 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_Ordered_Maps in
  33 --  the Ada 2012 RM. The modifications are to facilitate formal proofs by
  34 --  making it 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: Key, Element, Next, Query_Element, Previous,
  40 --    Has_Element, Iterate, Reverse_Iterate. This change is motivated by the
  41 --    need to 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. The operators "<" and ">" that could not be modified that way
  45 --    have been removed.
  46
  47 --    There are four new functions:
  48
  49 --      function Strict_Equal (Left, Right : Map) return Boolean;
  50 --      function Overlap (Left, Right : Map) return Boolean;
  51 --      function Left  (Container : Map; Position : Cursor) return Map;
  52 --      function Right (Container : Map; Position : Cursor) return Map;
  53
  54 --    See detailed specifications for these subprograms
  55
  56 private with Ada.Containers.Red_Black_Trees;
  57 private with Ada.Streams;
  58
  59 generic
  60    type Key_Type is private;
  61    type Element_Type is private;
  62
  63    with function "<" (Left, Right : Key_Type) return Boolean is <>;
  64    with function "=" (Left, Right : Element_Type) return Boolean is <>;
  65
  66 package Ada.Containers.Formal_Ordered_Maps is
  67    pragma Pure;
  68
  69    function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
  70
  71    type Map (Capacity : Count_Type) is tagged private;
  72    pragma Preelaborable_Initialization (Map);
  73
  74    type Cursor is private;
  75    pragma Preelaborable_Initialization (Cursor);
  76
  77    Empty_Map : constant Map;
  78
  79    No_Element : constant Cursor;
  80
  81    function "=" (Left, Right : Map) return Boolean;
  82
  83    function Length (Container : Map) return Count_Type;
  84
  85    function Is_Empty (Container : Map) return Boolean;
  86
  87    procedure Clear (Container : in out Map);
  88
  89    procedure Assign (Target : in out Map; Source : Map);
  90
  91    function Copy (Source : Map; Capacity : Count_Type := 0) return Map;
  92
  93    function Key (Container : Map; Position : Cursor) return Key_Type;
  94
  95    function Element (Container : Map; Position : Cursor) return Element_Type;
  96
  97    procedure Replace_Element
  98      (Container : in out Map;
  99       Position  : Cursor;
 100       New_Item  : Element_Type);
 101
 102    procedure Query_Element
 103      (Container : in out Map;
 104       Position  : Cursor;
 105       Process   : not null access
 106                     procedure (Key : Key_Type; Element : Element_Type));
 107
 108    procedure Update_Element
 109      (Container : in out Map;
 110       Position  : Cursor;
 111       Process   : not null access
 112                     procedure (Key : Key_Type; Element : in out Element_Type));
 113
 114    procedure Move (Target : in out Map; Source : in out Map);
 115
 116    procedure Insert
 117      (Container : in out Map;
 118       Key       : Key_Type;
 119       New_Item  : Element_Type;
 120       Position  : out Cursor;
 121       Inserted  : out Boolean);
 122
 123    procedure Insert
 124      (Container : in out Map;
 125       Key       : Key_Type;
 126       Position  : out Cursor;
 127       Inserted  : out Boolean);
 128
 129    procedure Insert
 130      (Container : in out Map;
 131       Key       : Key_Type;
 132       New_Item  : Element_Type);
 133
 134    procedure Include
 135      (Container : in out Map;
 136       Key       : Key_Type;
 137       New_Item  : Element_Type);
 138
 139    procedure Replace
 140      (Container : in out Map;
 141       Key       : Key_Type;
 142       New_Item  : Element_Type);
 143
 144    procedure Exclude (Container : in out Map; Key : Key_Type);
 145
 146    procedure Delete (Container : in out Map; Key : Key_Type);
 147
 148    procedure Delete (Container : in out Map; Position : in out Cursor);
 149
 150    procedure Delete_First (Container : in out Map);
 151
 152    procedure Delete_Last (Container : in out Map);
 153
 154    function First (Container : Map) return Cursor;
 155
 156    function First_Element (Container : Map) return Element_Type;
 157
 158    function First_Key (Container : Map) return Key_Type;
 159
 160    function Last (Container : Map) return Cursor;
 161
 162    function Last_Element (Container : Map) return Element_Type;
 163
 164    function Last_Key (Container : Map) return Key_Type;
 165
 166    function Next (Container : Map; Position : Cursor) return Cursor;
 167
 168    procedure Next (Container : Map; Position : in out Cursor);
 169
 170    function Previous (Container : Map; Position : Cursor) return Cursor;
 171
 172    procedure Previous (Container : Map; Position : in out Cursor);
 173
 174    function Find (Container : Map; Key : Key_Type) return Cursor;
 175
 176    function Element (Container : Map; Key : Key_Type) return Element_Type;
 177
 178    function Floor (Container : Map; Key : Key_Type) return Cursor;
 179
 180    function Ceiling (Container : Map; Key : Key_Type) return Cursor;
 181
 182    function Contains (Container : Map; Key : Key_Type) return Boolean;
 183
 184    function Has_Element (Container : Map; Position : Cursor) return Boolean;
 185
 186    procedure Iterate
 187      (Container : Map;
 188       Process   :
 189         not null access procedure (Container : Map; Position : Cursor));
 190
 191    procedure Reverse_Iterate
 192      (Container : Map;
 193       Process   : not null access
 194                     procedure (Container : Map; Position : Cursor));
 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 private
 213
 214    pragma Inline (Next);
 215    pragma Inline (Previous);
 216
 217    subtype Node_Access is Count_Type;
 218
 219    use Red_Black_Trees;
 220
 221    type Node_Type is record
 222       Has_Element : Boolean := False;
 223       Parent  : Node_Access := 0;
 224       Left    : Node_Access := 0;
 225       Right   : Node_Access := 0;
 226       Color   : Red_Black_Trees.Color_Type := Red;
 227       Key     : Key_Type;
 228       Element : Element_Type;
 229    end record;
 230
 231    package Tree_Types is
 232      new Ada.Containers.Red_Black_Trees.Generic_Bounded_Tree_Types (Node_Type);
 233
 234    type Map (Capacity : Count_Type) is
 235       new Tree_Types.Tree_Type (Capacity) with null record;
 236
 237    use Ada.Streams;
 238
 239    type Cursor is record
 240       Node : Node_Access;
 241    end record;
 242
 243    procedure Write
 244      (Stream : not null access Root_Stream_Type'Class;
 245       Item   : Cursor);
 246
 247    for Cursor'Write use Write;
 248
 249    procedure Read
 250      (Stream : not null access Root_Stream_Type'Class;
 251       Item   : out Cursor);
 252
 253    for Cursor'Read use Read;
 254
 255    No_Element : constant Cursor := (Node => 0);
 256
 257    procedure Write
 258      (Stream    : not null access Root_Stream_Type'Class;
 259       Container : Map);
 260
 261    for Map'Write use Write;
 262
 263    procedure Read
 264      (Stream    : not null access Root_Stream_Type'Class;
 265       Container : out Map);
 266
 267    for Map'Read use Read;
 268
 269    Empty_Map : constant Map := (Capacity => 0, others => <>);
 270
 271 end Ada.Containers.Formal_Ordered_Maps;