1 ------------------------------------------------------------------------------
3 -- GNAT LIBRARY COMPONENTS --
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 --
9 -- Copyright (C) 2004-2013, Free Software Foundation, Inc. --
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. --
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. --
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. --
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 ------------------------------------------------------------------------------
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.
36 -- The modifications are:
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
46 -- There are three new functions:
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;
52 -- See detailed specifications for these subprograms
54 private with Ada
.Containers
.Hash_Tables
;
57 type Element_Type
is private;
59 with function Hash
(Element
: Element_Type
) return Hash_Type
;
61 with function Equivalent_Elements
(Left
, Right
: Element_Type
)
64 with function "=" (Left
, Right
: Element_Type
) return Boolean is <>;
66 package Ada
.Containers
.Formal_Hashed_Sets
is
69 type Set
(Capacity
: Count_Type
; Modulus
: Hash_Type
) is private;
70 pragma Preelaborable_Initialization
(Set
);
72 type Cursor
is private;
73 pragma Preelaborable_Initialization
(Cursor
);
75 Empty_Set
: constant Set
;
77 No_Element
: constant Cursor
;
79 function "=" (Left
, Right
: Set
) return Boolean;
81 function Equivalent_Sets
(Left
, Right
: Set
) return Boolean;
83 function To_Set
(New_Item
: Element_Type
) return Set
;
85 function Capacity
(Container
: Set
) return Count_Type
;
87 procedure Reserve_Capacity
88 (Container
: in out Set
;
89 Capacity
: Count_Type
)
91 Pre
=> Capacity
<= Container
.Capacity
;
93 function Length
(Container
: Set
) return Count_Type
;
95 function Is_Empty
(Container
: Set
) return Boolean;
97 procedure Clear
(Container
: in out Set
);
99 procedure Assign
(Target
: in out Set
; Source
: Set
) with
100 Pre
=> Target
.Capacity
>= Length
(Source
);
104 Capacity
: Count_Type
:= 0) return Set
106 Pre
=> Capacity
>= Source
.Capacity
;
110 Position
: Cursor
) return Element_Type
112 Pre
=> Has_Element
(Container
, Position
);
114 procedure Replace_Element
115 (Container
: in out Set
;
117 New_Item
: Element_Type
)
119 Pre
=> Has_Element
(Container
, Position
);
121 procedure Move
(Target
: in out Set
; Source
: in out Set
) with
122 Pre
=> Target
.Capacity
>= Length
(Source
);
125 (Container
: in out Set
;
126 New_Item
: Element_Type
;
127 Position
: out Cursor
;
128 Inserted
: out Boolean)
130 Pre
=> Length
(Container
) < Container
.Capacity
;
132 procedure Insert
(Container
: in out Set
; New_Item
: Element_Type
) with
133 Pre
=> Length
(Container
) < Container
.Capacity
134 and then (not Contains
(Container
, New_Item
));
136 procedure Include
(Container
: in out Set
; New_Item
: Element_Type
) with
137 Pre
=> Length
(Container
) < Container
.Capacity
;
139 procedure Replace
(Container
: in out Set
; New_Item
: Element_Type
) with
140 Pre
=> Contains
(Container
, New_Item
);
142 procedure Exclude
(Container
: in out Set
; Item
: Element_Type
);
144 procedure Delete
(Container
: in out Set
; Item
: Element_Type
) with
145 Pre
=> Contains
(Container
, Item
);
147 procedure Delete
(Container
: in out Set
; Position
: in out Cursor
) with
148 Pre
=> Has_Element
(Container
, Position
);
150 procedure Union
(Target
: in out Set
; Source
: Set
) with
151 Pre
=> Length
(Target
) + Length
(Source
) -
152 Length
(Intersection
(Target
, Source
)) <= Target
.Capacity
;
154 function Union
(Left
, Right
: Set
) return Set
;
156 function "or" (Left
, Right
: Set
) return Set
renames Union
;
158 procedure Intersection
(Target
: in out Set
; Source
: Set
);
160 function Intersection
(Left
, Right
: Set
) return Set
;
162 function "and" (Left
, Right
: Set
) return Set
renames Intersection
;
164 procedure Difference
(Target
: in out Set
; Source
: Set
);
166 function Difference
(Left
, Right
: Set
) return Set
;
168 function "-" (Left
, Right
: Set
) return Set
renames Difference
;
170 procedure Symmetric_Difference
(Target
: in out Set
; Source
: Set
);
172 function Symmetric_Difference
(Left
, Right
: Set
) return Set
;
174 function "xor" (Left
, Right
: Set
) return Set
175 renames Symmetric_Difference
;
177 function Overlap
(Left
, Right
: Set
) return Boolean;
179 function Is_Subset
(Subset
: Set
; Of_Set
: Set
) return Boolean;
181 function First
(Container
: Set
) return Cursor
;
183 function Next
(Container
: Set
; Position
: Cursor
) return Cursor
with
184 Pre
=> Has_Element
(Container
, Position
) or else Position
= No_Element
;
186 procedure Next
(Container
: Set
; Position
: in out Cursor
) with
187 Pre
=> Has_Element
(Container
, Position
) or else Position
= No_Element
;
191 Item
: Element_Type
) return Cursor
;
193 function Contains
(Container
: Set
; Item
: Element_Type
) return Boolean;
195 function Has_Element
(Container
: Set
; Position
: Cursor
) return Boolean;
197 function Equivalent_Elements
(Left
: Set
; CLeft
: Cursor
;
198 Right
: Set
; CRight
: Cursor
) return Boolean;
200 function Equivalent_Elements
201 (Left
: Set
; CLeft
: Cursor
;
202 Right
: Element_Type
) return Boolean;
204 function Equivalent_Elements
205 (Left
: Element_Type
;
206 Right
: Set
; CRight
: Cursor
) return Boolean;
208 function Default_Modulus
(Capacity
: Count_Type
) return Hash_Type
;
211 type Key_Type
(<>) is private;
213 with function Key
(Element
: Element_Type
) return Key_Type
;
215 with function Hash
(Key
: Key_Type
) return Hash_Type
;
217 with function Equivalent_Keys
(Left
, Right
: Key_Type
) return Boolean;
219 package Generic_Keys
is
221 function Key
(Container
: Set
; Position
: Cursor
) return Key_Type
;
223 function Element
(Container
: Set
; Key
: Key_Type
) return Element_Type
;
226 (Container
: in out Set
;
228 New_Item
: Element_Type
);
230 procedure Exclude
(Container
: in out Set
; Key
: Key_Type
);
232 procedure Delete
(Container
: in out Set
; Key
: Key_Type
);
234 function Find
(Container
: Set
; Key
: Key_Type
) return Cursor
;
236 function Contains
(Container
: Set
; Key
: Key_Type
) return Boolean;
240 function Strict_Equal
(Left
, Right
: Set
) return Boolean;
241 -- Strict_Equal returns True if the containers are physically equal, i.e.
242 -- they are structurally equal (function "=" returns True) and that they
243 -- have the same set of cursors.
245 function Left
(Container
: Set
; Position
: Cursor
) return Set
with
246 Pre
=> Has_Element
(Container
, Position
) or else Position
= No_Element
;
247 function Right
(Container
: Set
; Position
: Cursor
) return Set
with
248 Pre
=> Has_Element
(Container
, Position
) or else Position
= No_Element
;
249 -- Left returns a container containing all elements preceding Position
250 -- (excluded) in Container. Right returns a container containing all
251 -- elements following Position (included) in Container. These two new
252 -- functions can be used to express invariant properties in loops which
253 -- iterate over containers. Left returns the part of the container already
254 -- scanned and Right the part not scanned yet.
258 pragma Inline
(Next
);
262 Element
: Element_Type
;
264 Has_Element
: Boolean := False;
267 package HT_Types
is new
268 Ada
.Containers
.Hash_Tables
.Generic_Bounded_Hash_Table_Types
(Node_Type
);
270 type Set
(Capacity
: Count_Type
; Modulus
: Hash_Type
) is
271 new HT_Types
.Hash_Table_Type
(Capacity
, Modulus
) with null record;
275 type Cursor
is record
279 No_Element
: constant Cursor
:= (Node
=> 0);
281 Empty_Set
: constant Set
:= (Capacity
=> 0, Modulus
=> 0, others => <>);
283 end Ada
.Containers
.Formal_Hashed_Sets
;