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 _ 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_Ordered_Sets 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
42--    a 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 three new functions:
48
49--      function Strict_Equal (Left, Right : Set) return Boolean;
50--      function Left  (Container : Set; Position : Cursor) return Set;
51--      function Right (Container : Set; Position : Cursor) return Set;
52
53--    See detailed specifications for these subprograms
54
55private with Ada.Containers.Red_Black_Trees;
56private with Ada.Streams;
57
58generic
59   type Element_Type is private;
60
61   with function "<" (Left, Right : Element_Type) return Boolean is <>;
62   with function "=" (Left, Right : Element_Type) return Boolean is <>;
63
64package Ada.Containers.Formal_Ordered_Sets is
65   pragma Pure;
66
67   function Equivalent_Elements (Left, Right : Element_Type) return Boolean;
68
69   type Set (Capacity : Count_Type) is tagged private;
70   --  why is this commented out ???
71   --  pragma Preelaborable_Initialization (Set);
72
73   type Cursor is private;
74   pragma Preelaborable_Initialization (Cursor);
75
76   Empty_Set : constant Set;
77
78   No_Element : constant Cursor;
79
80   function "=" (Left, Right : Set) return Boolean;
81
82   function Equivalent_Sets (Left, Right : Set) return Boolean;
83
84   function To_Set (New_Item : Element_Type) return Set;
85
86   function Length (Container : Set) return Count_Type;
87
88   function Is_Empty (Container : Set) return Boolean;
89
90   procedure Clear (Container : in out Set);
91
92   procedure Assign (Target : in out Set; Source : Set);
93
94   function Copy (Source : Set; Capacity : Count_Type := 0) return Set;
95
96   function Element (Container : Set; Position : Cursor) return Element_Type;
97
98   procedure Replace_Element
99     (Container : in out Set;
100      Position  : Cursor;
101      New_Item  : Element_Type);
102
103   procedure Query_Element
104     (Container : in out Set;
105      Position  : Cursor;
106      Process   : not null access procedure (Element : Element_Type));
107
108   procedure Move (Target : in out Set; Source : in out Set);
109
110   procedure Insert
111     (Container : in out Set;
112      New_Item  : Element_Type;
113      Position  : out Cursor;
114      Inserted  : out Boolean);
115
116   procedure Insert
117     (Container : in out Set;
118      New_Item  : Element_Type);
119
120   procedure Include
121     (Container : in out Set;
122      New_Item  : Element_Type);
123
124   procedure Replace
125     (Container : in out Set;
126      New_Item  : Element_Type);
127
128   procedure Exclude
129     (Container : in out Set;
130      Item      : Element_Type);
131
132   procedure Delete
133     (Container : in out Set;
134      Item      : Element_Type);
135
136   procedure Delete
137     (Container : in out Set;
138      Position  : in out Cursor);
139
140   procedure Delete_First (Container : in out Set);
141
142   procedure Delete_Last (Container : in out Set);
143
144   procedure Union (Target : in out Set; Source : Set);
145
146   function Union (Left, Right : Set) return Set;
147
148   function "or" (Left, Right : Set) return Set renames Union;
149
150   procedure Intersection (Target : in out Set; Source : Set);
151
152   function Intersection (Left, Right : Set) return Set;
153
154   function "and" (Left, Right : Set) return Set renames Intersection;
155
156   procedure Difference (Target : in out Set; Source : Set);
157
158   function Difference (Left, Right : Set) return Set;
159
160   function "-" (Left, Right : Set) return Set renames Difference;
161
162   procedure Symmetric_Difference (Target : in out Set; Source : Set);
163
164   function Symmetric_Difference (Left, Right : Set) return Set;
165
166   function "xor" (Left, Right : Set) return Set renames Symmetric_Difference;
167
168   function Overlap (Left, Right : Set) return Boolean;
169
170   function Is_Subset (Subset : Set; Of_Set : Set) return Boolean;
171
172   function First (Container : Set) return Cursor;
173
174   function First_Element (Container : Set) return Element_Type;
175
176   function Last (Container : Set) return Cursor;
177
178   function Last_Element (Container : Set) return Element_Type;
179
180   function Next (Container : Set; Position : Cursor) return Cursor;
181
182   procedure Next (Container : Set; Position : in out Cursor);
183
184   function Previous (Container : Set; Position : Cursor) return Cursor;
185
186   procedure Previous (Container : Set; Position : in out Cursor);
187
188   function Find (Container : Set; Item : Element_Type) return Cursor;
189
190   function Floor (Container : Set; Item : Element_Type) return Cursor;
191
192   function Ceiling (Container : Set; Item : Element_Type) return Cursor;
193
194   function Contains (Container : Set; Item : Element_Type) return Boolean;
195
196   function Has_Element (Container : Set; Position : Cursor) return Boolean;
197
198   procedure Iterate
199     (Container : Set;
200      Process   :
201        not null access procedure (Container : Set; Position : Cursor));
202
203   procedure Reverse_Iterate
204     (Container : Set;
205      Process   : not null access
206                    procedure (Container : Set; Position : Cursor));
207
208   generic
209      type Key_Type (<>) is private;
210
211      with function Key (Element : Element_Type) return Key_Type;
212
213      with function "<" (Left, Right : Key_Type) return Boolean is <>;
214
215   package Generic_Keys is
216
217      function Equivalent_Keys (Left, Right : Key_Type) return Boolean;
218
219      function Key (Container : Set; Position : Cursor) return Key_Type;
220
221      function Element (Container : Set; Key : Key_Type) return Element_Type;
222
223      procedure Replace
224        (Container : in out Set;
225         Key       : Key_Type;
226         New_Item  : Element_Type);
227
228      procedure Exclude (Container : in out Set; Key : Key_Type);
229
230      procedure Delete (Container : in out Set; Key : Key_Type);
231
232      function Find (Container : Set; Key : Key_Type) return Cursor;
233
234      function Floor (Container : Set; Key : Key_Type) return Cursor;
235
236      function Ceiling (Container : Set; Key : Key_Type) return Cursor;
237
238      function Contains (Container : Set; Key : Key_Type) return Boolean;
239
240      procedure Update_Element_Preserving_Key
241        (Container : in out Set;
242         Position  : Cursor;
243         Process   : not null access
244                       procedure (Element : in out Element_Type));
245
246   end Generic_Keys;
247
248   function Strict_Equal (Left, Right : Set) return Boolean;
249   --  Strict_Equal returns True if the containers are physically equal, i.e.
250   --  they are structurally equal (function "=" returns True) and that they
251   --  have the same set of cursors.
252
253   function Left  (Container : Set; Position : Cursor) return Set;
254   function Right (Container : Set; Position : Cursor) return Set;
255   --  Left returns a container containing all elements preceding Position
256   --  (excluded) in Container. Right returns a container containing all
257   --  elements following Position (included) in Container. These two new
258   --  functions can be used to express invariant properties in loops which
259   --  iterate over containers. Left returns the part of the container already
260   --  scanned and Right the part not scanned yet.
261
262private
263
264   pragma Inline (Next);
265   pragma Inline (Previous);
266
267   type Node_Type is record
268      Has_Element : Boolean := False;
269      Parent  : Count_Type := 0;
270      Left    : Count_Type := 0;
271      Right   : Count_Type := 0;
272      Color   : Red_Black_Trees.Color_Type;
273      Element : Element_Type;
274   end record;
275
276   package Tree_Types is
277     new Red_Black_Trees.Generic_Bounded_Tree_Types (Node_Type);
278
279   type Set (Capacity : Count_Type) is
280     new Tree_Types.Tree_Type (Capacity) with null record;
281
282   use Red_Black_Trees;
283   use Ada.Streams;
284
285   type Set_Access is access all Set;
286   for Set_Access'Storage_Size use 0;
287
288   type Cursor is record
289      Node : Count_Type;
290   end record;
291
292   procedure Write
293     (Stream : not null access Root_Stream_Type'Class;
294      Item   : Cursor);
295
296   for Cursor'Write use Write;
297
298   procedure Read
299     (Stream : not null access Root_Stream_Type'Class;
300      Item   : out Cursor);
301
302   for Cursor'Read use Read;
303
304   No_Element : constant Cursor := (Node => 0);
305
306   procedure Write
307     (Stream    : not null access Root_Stream_Type'Class;
308      Container : Set);
309
310   for Set'Write use Write;
311
312   procedure Read
313     (Stream    : not null access Root_Stream_Type'Class;
314      Container : out Set);
315
316   for Set'Read use Read;
317
318   Empty_Set : constant Set := (Capacity => 0, others => <>);
319
320end Ada.Containers.Formal_Ordered_Sets;
321