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) 2004-2015, 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 meant to facilitate formal proofs by 34-- making it easier to express properties, and by making the specification of 35-- this unit compatible with SPARK 2014. Note that the API of this unit may be 36-- subject to incompatible changes as SPARK 2014 evolves. 37 38-- The modifications are: 39 40-- A parameter for the container is added to every function reading the 41-- contents of a container: Key, Element, Next, Query_Element, Has_Element, 42-- Iterate, Equivalent_Keys. This change is motivated by the need to have 43-- cursors which are valid on different containers (typically a container C 44-- and its previous version C'Old) for expressing properties, which is not 45-- possible if cursors encapsulate an access to the underlying container. 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 First_To_Previous (Container : Map; Current : Cursor) 52-- return Map; 53-- function Current_To_Last (Container : Map; Current : Cursor) 54-- return Map; 55 56-- See detailed specifications for these subprograms 57 58private with Ada.Containers.Hash_Tables; 59 60generic 61 type Key_Type is private; 62 type Element_Type is private; 63 64 with function Hash (Key : Key_Type) return Hash_Type; 65 with function Equivalent_Keys (Left, Right : Key_Type) return Boolean; 66 with function "=" (Left, Right : Element_Type) return Boolean is <>; 67 68package Ada.Containers.Formal_Hashed_Maps with 69 Pure, 70 SPARK_Mode 71is 72 pragma Annotate (GNATprove, External_Axiomatization); 73 74 type Map (Capacity : Count_Type; Modulus : Hash_Type) is private with 75 Iterable => (First => First, 76 Next => Next, 77 Has_Element => Has_Element, 78 Element => Element), 79 Default_Initial_Condition => Is_Empty (Map); 80 pragma Preelaborable_Initialization (Map); 81 82 type Cursor is private; 83 pragma Preelaborable_Initialization (Cursor); 84 85 Empty_Map : constant Map; 86 87 No_Element : constant Cursor; 88 89 function "=" (Left, Right : Map) return Boolean with 90 Global => null; 91 92 function Capacity (Container : Map) return Count_Type with 93 Global => null; 94 95 procedure Reserve_Capacity 96 (Container : in out Map; 97 Capacity : Count_Type) 98 with 99 Global => null, 100 Pre => Capacity <= Container.Capacity; 101 102 function Length (Container : Map) return Count_Type with 103 Global => null; 104 105 function Is_Empty (Container : Map) return Boolean with 106 Global => null; 107 108 procedure Clear (Container : in out Map) with 109 Global => null; 110 111 procedure Assign (Target : in out Map; Source : Map) with 112 Global => null, 113 Pre => Target.Capacity >= Length (Source); 114 115 function Copy 116 (Source : Map; 117 Capacity : Count_Type := 0) return Map 118 with 119 Global => null, 120 Pre => Capacity = 0 or else Capacity >= Source.Capacity; 121 -- Copy returns a container stricty equal to Source. It must have 122 -- the same cursors associated with each element. Therefore: 123 -- - capacity=0 means use container.capacity as capacity of target 124 -- - the modulus cannot be changed. 125 126 function Key (Container : Map; Position : Cursor) return Key_Type with 127 Global => null, 128 Pre => Has_Element (Container, Position); 129 130 function Element 131 (Container : Map; 132 Position : Cursor) return Element_Type 133 with 134 Global => null, 135 Pre => Has_Element (Container, Position); 136 137 procedure Replace_Element 138 (Container : in out Map; 139 Position : Cursor; 140 New_Item : Element_Type) 141 with 142 Global => null, 143 Pre => Has_Element (Container, Position); 144 145 procedure Move (Target : in out Map; Source : in out Map) with 146 Global => null, 147 Pre => Target.Capacity >= Length (Source); 148 149 procedure Insert 150 (Container : in out Map; 151 Key : Key_Type; 152 New_Item : Element_Type; 153 Position : out Cursor; 154 Inserted : out Boolean) 155 with 156 Global => null, 157 Pre => Length (Container) < Container.Capacity; 158 159 procedure Insert 160 (Container : in out Map; 161 Key : Key_Type; 162 New_Item : Element_Type) 163 with 164 Global => null, 165 Pre => Length (Container) < Container.Capacity 166 and then (not Contains (Container, Key)); 167 168 procedure Include 169 (Container : in out Map; 170 Key : Key_Type; 171 New_Item : Element_Type) 172 with 173 Global => null, 174 Pre => Length (Container) < Container.Capacity; 175 176 procedure Replace 177 (Container : in out Map; 178 Key : Key_Type; 179 New_Item : Element_Type) 180 with 181 Global => null, 182 Pre => Contains (Container, Key); 183 184 procedure Exclude (Container : in out Map; Key : Key_Type) with 185 Global => null; 186 187 procedure Delete (Container : in out Map; Key : Key_Type) with 188 Global => null, 189 Pre => Contains (Container, Key); 190 191 procedure Delete (Container : in out Map; Position : in out Cursor) with 192 Global => null, 193 Pre => Has_Element (Container, Position); 194 195 function First (Container : Map) return Cursor with 196 Global => null; 197 198 function Next (Container : Map; Position : Cursor) return Cursor with 199 Global => null, 200 Pre => Has_Element (Container, Position) or else Position = No_Element; 201 202 procedure Next (Container : Map; Position : in out Cursor) with 203 Global => null, 204 Pre => Has_Element (Container, Position) or else Position = No_Element; 205 206 function Find (Container : Map; Key : Key_Type) return Cursor with 207 Global => null; 208 209 function Contains (Container : Map; Key : Key_Type) return Boolean with 210 Global => null; 211 212 function Element (Container : Map; Key : Key_Type) return Element_Type with 213 Global => null, 214 Pre => Contains (Container, Key); 215 216 function Has_Element (Container : Map; Position : Cursor) return Boolean 217 with 218 Global => null; 219 220 function Equivalent_Keys 221 (Left : Map; 222 CLeft : Cursor; 223 Right : Map; 224 CRight : Cursor) return Boolean 225 with 226 Global => null; 227 228 function Equivalent_Keys 229 (Left : Map; 230 CLeft : Cursor; 231 Right : Key_Type) return Boolean 232 with 233 Global => null; 234 235 function Equivalent_Keys 236 (Left : Key_Type; 237 Right : Map; 238 CRight : Cursor) return Boolean 239 with 240 Global => null; 241 242 function Default_Modulus (Capacity : Count_Type) return Hash_Type with 243 Global => null; 244 245 function Strict_Equal (Left, Right : Map) return Boolean with 246 Ghost, 247 Global => null; 248 -- Strict_Equal returns True if the containers are physically equal, i.e. 249 -- they are structurally equal (function "=" returns True) and that they 250 -- have the same set of cursors. 251 252 function First_To_Previous (Container : Map; Current : Cursor) return Map 253 with 254 Ghost, 255 Global => null, 256 Pre => Has_Element (Container, Current) or else Current = No_Element; 257 258 function Current_To_Last (Container : Map; Current : Cursor) return Map 259 with 260 Ghost, 261 Global => null, 262 Pre => Has_Element (Container, Current) or else Current = No_Element; 263 -- First_To_Previous returns a container containing all elements preceding 264 -- Current (excluded) in Container. Current_To_Last returns a container 265 -- containing all elements following Current (included) in Container. 266 -- These two new functions can be used to express invariant properties in 267 -- loops which iterate over containers. First_To_Previous returns the part 268 -- of the container already scanned and Current_To_Last the part not 269 -- scanned yet. 270 271 function Overlap (Left, Right : Map) return Boolean with 272 Global => null; 273 -- Overlap returns True if the containers have common keys 274 275private 276 pragma SPARK_Mode (Off); 277 278 pragma Inline (Length); 279 pragma Inline (Is_Empty); 280 pragma Inline (Clear); 281 pragma Inline (Key); 282 pragma Inline (Element); 283 pragma Inline (Contains); 284 pragma Inline (Capacity); 285 pragma Inline (Has_Element); 286 pragma Inline (Equivalent_Keys); 287 pragma Inline (Next); 288 289 type Node_Type is record 290 Key : Key_Type; 291 Element : Element_Type; 292 Next : Count_Type; 293 Has_Element : Boolean := False; 294 end record; 295 296 package HT_Types is new 297 Ada.Containers.Hash_Tables.Generic_Bounded_Hash_Table_Types (Node_Type); 298 299 type Map (Capacity : Count_Type; Modulus : Hash_Type) is 300 new HT_Types.Hash_Table_Type (Capacity, Modulus) with null record; 301 302 use HT_Types; 303 304 type Cursor is record 305 Node : Count_Type; 306 end record; 307 308 Empty_Map : constant Map := (Capacity => 0, Modulus => 0, others => <>); 309 310 No_Element : constant Cursor := (Node => 0); 311 312end Ada.Containers.Formal_Hashed_Maps; 313