gcc/ada/a-cfdlli.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT LIBRARY COMPONENTS                          --
   4 --                                                                          --
   5 --                 ADA.CONTAINERS.FORMAL_DOUBLY_LINKED_LISTS                --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 2004-2012, 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 Ada.Containers.Bounded_Doubly_Linked_Lists 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: Next, Previous, Query_Element, Has_Element,
  40 --    Iterate, Reverse_Iterate, Element. This change is motivated by the need
  41 --    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.
  45
  46 --    There are three new functions:
  47
  48 --      function Strict_Equal (Left, Right : List) return Boolean;
  49 --      function Left  (Container : List; Position : Cursor) return List;
  50 --      function Right (Container : List; Position : Cursor) return List;
  51
  52 --    See detailed specifications for these subprograms
  53
  54 private with Ada.Streams;
  55 with Ada.Containers;
  56 with Ada.Iterator_Interfaces;
  57
  58 generic
  59    type Element_Type is private;
  60
  61    with function "=" (Left, Right : Element_Type)
  62                       return Boolean is <>;
  63
  64 package Ada.Containers.Formal_Doubly_Linked_Lists is
  65    pragma Pure;
  66
  67    type List (Capacity : Count_Type) is tagged private with
  68       Constant_Indexing => Constant_Reference,
  69       Default_Iterator  => Iterate,
  70       Iterator_Element  => Element_Type;
  71    --  pragma Preelaborable_Initialization (List);
  72
  73    type Cursor is private;
  74    pragma Preelaborable_Initialization (Cursor);
  75
  76    Empty_List : constant List;
  77
  78    No_Element : constant Cursor;
  79
  80    function Not_No_Element (Position : Cursor) return Boolean;
  81
  82    package List_Iterator_Interfaces is new
  83      Ada.Iterator_Interfaces (Cursor => Cursor, Has_Element => Not_No_Element);
  84
  85    function Iterate (Container : List; Start : Cursor)
  86       return List_Iterator_Interfaces.Reversible_Iterator'Class;
  87
  88    function Iterate (Container : List)
  89       return List_Iterator_Interfaces.Reversible_Iterator'Class;
  90
  91    function "=" (Left, Right : List) return Boolean;
  92
  93    function Length (Container : List) return Count_Type;
  94
  95    function Is_Empty (Container : List) return Boolean;
  96
  97    procedure Clear (Container : in out List);
  98
  99    procedure Assign (Target : in out List; Source : List);
 100
 101    function Copy (Source : List; Capacity : Count_Type := 0) return List;
 102
 103    function Element (Container : List; Position : Cursor) return Element_Type;
 104
 105    procedure Replace_Element
 106      (Container : in out List;
 107       Position  : Cursor;
 108       New_Item  : Element_Type);
 109
 110    procedure Query_Element
 111      (Container : List; Position : Cursor;
 112       Process   : not null access procedure (Element : Element_Type));
 113
 114    procedure Update_Element
 115      (Container : in out List;
 116       Position  : Cursor;
 117       Process   : not null access procedure (Element : in out Element_Type));
 118
 119    procedure Move (Target : in out List; Source : in out List);
 120
 121    procedure Insert
 122      (Container : in out List;
 123       Before    : Cursor;
 124       New_Item  : Element_Type;
 125       Count     : Count_Type := 1);
 126
 127    procedure Insert
 128      (Container : in out List;
 129       Before    : Cursor;
 130       New_Item  : Element_Type;
 131       Position  : out Cursor;
 132       Count     : Count_Type := 1);
 133
 134    procedure Insert
 135      (Container : in out List;
 136       Before    : Cursor;
 137       Position  : out Cursor;
 138       Count     : Count_Type := 1);
 139
 140    procedure Prepend
 141      (Container : in out List;
 142       New_Item  : Element_Type;
 143       Count     : Count_Type := 1);
 144
 145    procedure Append
 146      (Container : in out List;
 147       New_Item  : Element_Type;
 148       Count     : Count_Type := 1);
 149
 150    procedure Delete
 151      (Container : in out List;
 152       Position  : in out Cursor;
 153       Count     : Count_Type := 1);
 154
 155    procedure Delete_First
 156      (Container : in out List;
 157       Count     : Count_Type := 1);
 158
 159    procedure Delete_Last
 160      (Container : in out List;
 161       Count     : Count_Type := 1);
 162
 163    procedure Reverse_Elements (Container : in out List);
 164
 165    procedure Swap
 166      (Container : in out List;
 167       I, J      : Cursor);
 168
 169    procedure Swap_Links
 170      (Container : in out List;
 171       I, J      : Cursor);
 172
 173    procedure Splice
 174      (Target : in out List;
 175       Before : Cursor;
 176       Source : in out List);
 177
 178    procedure Splice
 179      (Target   : in out List;
 180       Before   : Cursor;
 181       Source   : in out List;
 182       Position : in out Cursor);
 183
 184    procedure Splice
 185      (Container : in out List;
 186       Before    : Cursor;
 187       Position  : Cursor);
 188
 189    function First (Container : List) return Cursor;
 190
 191    function First_Element (Container : List) return Element_Type;
 192
 193    function Last (Container : List) return Cursor;
 194
 195    function Last_Element (Container : List) return Element_Type;
 196
 197    function Next (Container : List; Position : Cursor) return Cursor;
 198
 199    procedure Next (Container : List; Position : in out Cursor);
 200
 201    function Previous (Container : List; Position : Cursor) return Cursor;
 202
 203    procedure Previous (Container : List; Position : in out Cursor);
 204
 205    function Find
 206      (Container : List;
 207       Item      : Element_Type;
 208       Position  : Cursor := No_Element) return Cursor;
 209
 210    function Reverse_Find
 211      (Container : List;
 212       Item      : Element_Type;
 213       Position  : Cursor := No_Element) return Cursor;
 214
 215    function Contains
 216      (Container : List;
 217       Item      : Element_Type) return Boolean;
 218
 219    function Has_Element (Container : List; Position : Cursor) return Boolean;
 220
 221    procedure Iterate
 222      (Container : List;
 223       Process   :
 224       not null access procedure (Container : List; Position : Cursor));
 225
 226    procedure Reverse_Iterate
 227      (Container : List;
 228       Process   :
 229       not null access procedure (Container : List; Position : Cursor));
 230
 231    generic
 232       with function "<" (Left, Right : Element_Type) return Boolean is <>;
 233    package Generic_Sorting is
 234
 235       function Is_Sorted (Container : List) return Boolean;
 236
 237       procedure Sort (Container : in out List);
 238
 239       procedure Merge (Target, Source : in out List);
 240
 241    end Generic_Sorting;
 242
 243    type Constant_Reference_Type
 244       (Element : not null access constant Element_Type) is private
 245    with
 246       Implicit_Dereference => Element;
 247
 248    function Constant_Reference
 249      (Container : List;      --  SHOULD BE ALIASED ???
 250       Position  : Cursor)   return Constant_Reference_Type;
 251
 252    function Strict_Equal (Left, Right : List) return Boolean;
 253    --  Strict_Equal returns True if the containers are physically equal, i.e.
 254    --  they are structurally equal (function "=" returns True) and that they
 255    --  have the same set of cursors.
 256
 257    function Left  (Container : List; Position : Cursor) return List;
 258    function Right (Container : List; Position : Cursor) return List;
 259    --  Left returns a container containing all elements preceding Position
 260    --  (excluded) in Container. Right returns a container containing all
 261    --  elements following Position (included) in Container. These two new
 262    --  functions can be used to express invariant properties in loops which
 263    --  iterate over containers. Left returns the part of the container already
 264    --  scanned and Right the part not scanned yet.
 265
 266 private
 267
 268    type Node_Type is record
 269       Prev    : Count_Type'Base := -1;
 270       Next    : Count_Type;
 271       Element : aliased Element_Type;
 272    end record;
 273
 274    function "=" (L, R : Node_Type) return Boolean is abstract;
 275
 276    type Node_Array is array (Count_Type range <>) of Node_Type;
 277    function "=" (L, R : Node_Array) return Boolean is abstract;
 278
 279    type List (Capacity : Count_Type) is tagged record
 280       Nodes  : Node_Array (1 .. Capacity) := (others => <>);
 281       Free   : Count_Type'Base := -1;
 282       Busy   : Natural := 0;
 283       Lock   : Natural := 0;
 284       Length : Count_Type := 0;
 285       First  : Count_Type := 0;
 286       Last   : Count_Type := 0;
 287    end record;
 288
 289    use Ada.Streams;
 290
 291    procedure Read
 292      (Stream : not null access Root_Stream_Type'Class;
 293       Item   : out List);
 294
 295    for List'Read use Read;
 296
 297    procedure Write
 298      (Stream : not null access Root_Stream_Type'Class;
 299       Item   : List);
 300
 301    for List'Write use Write;
 302
 303    type List_Access is access all List;
 304    for List_Access'Storage_Size use 0;
 305
 306    type Cursor is record
 307       Node : Count_Type := 0;
 308    end record;
 309
 310    type Constant_Reference_Type
 311       (Element : not null access constant Element_Type) is null record;
 312
 313    procedure Read
 314      (Stream : not null access Root_Stream_Type'Class;
 315       Item   : out Cursor);
 316
 317    for Cursor'Read use Read;
 318
 319    procedure Write
 320      (Stream : not null access Root_Stream_Type'Class;
 321       Item   : Cursor);
 322
 323    for Cursor'Write use Write;
 324
 325    Empty_List : constant List := (0, others => <>);
 326
 327    No_Element : constant Cursor := (Node => 0);
 328
 329 end Ada.Containers.Formal_Doubly_Linked_Lists;