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) 2004-2013, 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 is 69 pragma Annotate (GNATprove, External_Axiomatization); 70 pragma Pure; 71 72 type Map (Capacity : Count_Type; Modulus : Hash_Type) is private with 73 Iterable => (First => First, 74 Next => Next, 75 Has_Element => Has_Element, 76 Element => Element); 77 pragma Preelaborable_Initialization (Map); 78 79 type Cursor is private; 80 pragma Preelaborable_Initialization (Cursor); 81 82 Empty_Map : constant Map; 83 84 No_Element : constant Cursor; 85 86 function "=" (Left, Right : Map) return Boolean with 87 Global => null; 88 89 function Capacity (Container : Map) return Count_Type with 90 Global => null; 91 92 procedure Reserve_Capacity 93 (Container : in out Map; 94 Capacity : Count_Type) 95 with 96 Global => null, 97 Pre => Capacity <= Container.Capacity; 98 99 function Length (Container : Map) return Count_Type with 100 Global => null; 101 102 function Is_Empty (Container : Map) return Boolean with 103 Global => null; 104 105 procedure Clear (Container : in out Map) with 106 Global => null; 107 108 procedure Assign (Target : in out Map; Source : Map) with 109 Global => null, 110 Pre => Target.Capacity >= Length (Source); 111 112 function Copy 113 (Source : Map; 114 Capacity : Count_Type := 0) return Map 115 with 116 Global => null, 117 Pre => Capacity = 0 or else Capacity >= Source.Capacity; 118 -- Copy returns a container stricty equal to Source. It must have 119 -- the same cursors associated with each element. Therefore: 120 -- - capacity=0 means use container.capacity as capacity of target 121 -- - the modulus cannot be changed. 122 123 function Key (Container : Map; Position : Cursor) return Key_Type with 124 Global => null, 125 Pre => Has_Element (Container, Position); 126 127 function Element 128 (Container : Map; 129 Position : Cursor) return Element_Type 130 with 131 Global => null, 132 Pre => Has_Element (Container, Position); 133 134 procedure Replace_Element 135 (Container : in out Map; 136 Position : Cursor; 137 New_Item : Element_Type) 138 with 139 Global => null, 140 Pre => Has_Element (Container, Position); 141 142 procedure Move (Target : in out Map; Source : in out Map) with 143 Global => null, 144 Pre => Target.Capacity >= Length (Source); 145 146 procedure Insert 147 (Container : in out Map; 148 Key : Key_Type; 149 New_Item : Element_Type; 150 Position : out Cursor; 151 Inserted : out Boolean) 152 with 153 Global => null, 154 Pre => Length (Container) < Container.Capacity; 155 156 procedure Insert 157 (Container : in out Map; 158 Key : Key_Type; 159 New_Item : Element_Type) 160 with 161 Global => null, 162 Pre => Length (Container) < Container.Capacity 163 and then (not Contains (Container, Key)); 164 165 procedure Include 166 (Container : in out Map; 167 Key : Key_Type; 168 New_Item : Element_Type) 169 with 170 Global => null, 171 Pre => Length (Container) < Container.Capacity; 172 173 procedure Replace 174 (Container : in out Map; 175 Key : Key_Type; 176 New_Item : Element_Type) 177 with 178 Global => null, 179 Pre => Contains (Container, Key); 180 181 procedure Exclude (Container : in out Map; Key : Key_Type) with 182 Global => null; 183 184 procedure Delete (Container : in out Map; Key : Key_Type) with 185 Global => null, 186 Pre => Contains (Container, Key); 187 188 procedure Delete (Container : in out Map; Position : in out Cursor) with 189 Global => null, 190 Pre => Has_Element (Container, Position); 191 192 function First (Container : Map) return Cursor with 193 Global => null; 194 195 function Next (Container : Map; Position : Cursor) return Cursor with 196 Global => null, 197 Pre => Has_Element (Container, Position) or else Position = No_Element; 198 199 procedure Next (Container : Map; Position : in out Cursor) with 200 Global => null, 201 Pre => Has_Element (Container, Position) or else Position = No_Element; 202 203 function Find (Container : Map; Key : Key_Type) return Cursor with 204 Global => null; 205 206 function Contains (Container : Map; Key : Key_Type) return Boolean with 207 Global => null; 208 209 function Element (Container : Map; Key : Key_Type) return Element_Type with 210 Global => null, 211 Pre => Contains (Container, Key); 212 213 function Has_Element (Container : Map; Position : Cursor) return Boolean 214 with 215 Global => null; 216 217 function Equivalent_Keys 218 (Left : Map; 219 CLeft : Cursor; 220 Right : Map; 221 CRight : Cursor) return Boolean 222 with 223 Global => null; 224 225 function Equivalent_Keys 226 (Left : Map; 227 CLeft : Cursor; 228 Right : Key_Type) return Boolean 229 with 230 Global => null; 231 232 function Equivalent_Keys 233 (Left : Key_Type; 234 Right : Map; 235 CRight : Cursor) return Boolean 236 with 237 Global => null; 238 239 function Default_Modulus (Capacity : Count_Type) return Hash_Type with 240 Global => null; 241 242 function Strict_Equal (Left, Right : Map) return Boolean with 243 Global => null; 244 -- Strict_Equal returns True if the containers are physically equal, i.e. 245 -- they are structurally equal (function "=" returns True) and that they 246 -- have the same set of cursors. 247 248 function First_To_Previous (Container : Map; Current : Cursor) return Map 249 with 250 Global => null, 251 Pre => Has_Element (Container, Current) or else Current = No_Element; 252 function Current_To_Last (Container : Map; Current : Cursor) return Map 253 with 254 Global => null, 255 Pre => Has_Element (Container, Current) or else Current = No_Element; 256 -- First_To_Previous returns a container containing all elements preceding 257 -- Current (excluded) in Container. Current_To_Last returns a container 258 -- containing all elements following Current (included) in Container. 259 -- These two new functions can be used to express invariant properties in 260 -- loops which iterate over containers. First_To_Previous returns the part 261 -- of the container already scanned and Current_To_Last the part not 262 -- scanned yet. 263 264 function Overlap (Left, Right : Map) return Boolean with 265 Global => null; 266 -- Overlap returns True if the containers have common keys 267 268private 269 pragma Inline (Length); 270 pragma Inline (Is_Empty); 271 pragma Inline (Clear); 272 pragma Inline (Key); 273 pragma Inline (Element); 274 pragma Inline (Contains); 275 pragma Inline (Capacity); 276 pragma Inline (Has_Element); 277 pragma Inline (Equivalent_Keys); 278 pragma Inline (Next); 279 280 type Node_Type is record 281 Key : Key_Type; 282 Element : Element_Type; 283 Next : Count_Type; 284 Has_Element : Boolean := False; 285 end record; 286 287 package HT_Types is new 288 Ada.Containers.Hash_Tables.Generic_Bounded_Hash_Table_Types 289 (Node_Type); 290 291 type Map (Capacity : Count_Type; Modulus : Hash_Type) is 292 new HT_Types.Hash_Table_Type (Capacity, Modulus) with null record; 293 294 use HT_Types; 295 296 type Cursor is record 297 Node : Count_Type; 298 end record; 299 300 Empty_Map : constant Map := (Capacity => 0, Modulus => 0, others => <>); 301 302 No_Element : constant Cursor := (Node => 0); 303 304end Ada.Containers.Formal_Hashed_Maps; 305