diff gcc/ada/libgnat/a-cfhama.ads @ 111:04ced10e8804

gcc 7
author kono
date Fri, 27 Oct 2017 22:46:09 +0900
parents
children 84e7813d76e9
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/ada/libgnat/a-cfhama.ads	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,813 @@
+------------------------------------------------------------------------------
+--                                                                          --
+--                         GNAT LIBRARY COMPONENTS                          --
+--                                                                          --
+--    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     --
+--                                                                          --
+--                                 S p e c                                  --
+--                                                                          --
+--          Copyright (C) 2004-2017, Free Software Foundation, Inc.         --
+--                                                                          --
+-- This specification is derived from the Ada Reference Manual for use with --
+-- GNAT. The copyright notice above, and the license provisions that follow --
+-- apply solely to the  contents of the part following the private keyword. --
+--                                                                          --
+-- GNAT is free software;  you can  redistribute it  and/or modify it under --
+-- terms of the  GNU General Public License as published  by the Free Soft- --
+-- ware  Foundation;  either version 3,  or (at your option) any later ver- --
+-- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
+-- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
+-- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
+--                                                                          --
+-- As a special exception under Section 7 of GPL version 3, you are granted --
+-- additional permissions described in the GCC Runtime Library Exception,   --
+-- version 3.1, as published by the Free Software Foundation.               --
+--                                                                          --
+-- You should have received a copy of the GNU General Public License and    --
+-- a copy of the GCC Runtime Library Exception along with this program;     --
+-- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
+-- <http://www.gnu.org/licenses/>.                                          --
+------------------------------------------------------------------------------
+
+--  This spec is derived from package Ada.Containers.Bounded_Hashed_Maps in the
+--  Ada 2012 RM. The modifications are meant to facilitate formal proofs by
+--  making it easier to express properties, and by making the specification of
+--  this unit compatible with SPARK 2014. Note that the API of this unit may be
+--  subject to incompatible changes as SPARK 2014 evolves.
+
+--  The modifications are:
+
+--    A parameter for the container is added to every function reading the
+--    contents of a container: Key, Element, Next, Query_Element, Has_Element,
+--    Iterate, Equivalent_Keys. This change is motivated by the need to have
+--    cursors which are valid on different containers (typically a container C
+--    and its previous version C'Old) for expressing properties, which is not
+--    possible if cursors encapsulate an access to the underlying container.
+
+--  Iteration over maps is done using the Iterable aspect, which is SPARK
+--  compatible. "For of" iteration ranges over keys instead of elements.
+
+with Ada.Containers.Functional_Vectors;
+with Ada.Containers.Functional_Maps;
+private with Ada.Containers.Hash_Tables;
+
+generic
+   type Key_Type is private;
+   type Element_Type is private;
+
+   with function Hash (Key : Key_Type) return Hash_Type;
+   with function Equivalent_Keys
+     (Left  : Key_Type;
+      Right : Key_Type) return Boolean is "=";
+
+package Ada.Containers.Formal_Hashed_Maps with
+  SPARK_Mode
+is
+   pragma Annotate (CodePeer, Skip_Analysis);
+
+   type Map (Capacity : Count_Type; Modulus : Hash_Type) is private with
+     Iterable => (First       => First,
+                  Next        => Next,
+                  Has_Element => Has_Element,
+                  Element     => Key),
+     Default_Initial_Condition => Is_Empty (Map);
+   pragma Preelaborable_Initialization (Map);
+
+   Empty_Map : constant Map;
+
+   type Cursor is record
+      Node : Count_Type;
+   end record;
+
+   No_Element : constant Cursor := (Node => 0);
+
+   function Length (Container : Map) return Count_Type with
+     Global => null,
+     Post   => Length'Result <= Container.Capacity;
+
+   pragma Unevaluated_Use_Of_Old (Allow);
+
+   package Formal_Model with Ghost is
+      subtype Positive_Count_Type is Count_Type range 1 .. Count_Type'Last;
+
+      package M is new Ada.Containers.Functional_Maps
+        (Element_Type    => Element_Type,
+         Key_Type        => Key_Type,
+         Equivalent_Keys => Equivalent_Keys);
+
+      function "="
+        (Left  : M.Map;
+         Right : M.Map) return Boolean renames M."=";
+
+      function "<="
+        (Left  : M.Map;
+         Right : M.Map) return Boolean renames M."<=";
+
+      package K is new Ada.Containers.Functional_Vectors
+        (Element_Type => Key_Type,
+         Index_Type   => Positive_Count_Type);
+
+      function "="
+        (Left  : K.Sequence;
+         Right : K.Sequence) return Boolean renames K."=";
+
+      function "<"
+        (Left  : K.Sequence;
+         Right : K.Sequence) return Boolean renames K."<";
+
+      function "<="
+        (Left  : K.Sequence;
+         Right : K.Sequence) return Boolean renames K."<=";
+
+      function Find (Container : K.Sequence; Key : Key_Type) return Count_Type
+      --  Search for Key in Container
+
+      with
+        Global => null,
+        Post =>
+          (if Find'Result > 0 then
+              Find'Result <= K.Length (Container)
+                and Equivalent_Keys (Key, K.Get (Container, Find'Result)));
+
+      function K_Keys_Included
+        (Left  : K.Sequence;
+         Right : K.Sequence) return Boolean
+      --  Return True if Right contains all the keys of Left
+
+      with
+        Global => null,
+        Post   =>
+          K_Keys_Included'Result =
+            (for all I in 1 .. K.Length (Left) =>
+              Find (Right, K.Get (Left, I)) > 0
+                and then K.Get (Right, Find (Right, K.Get (Left, I))) =
+                         K.Get (Left, I));
+
+      package P is new Ada.Containers.Functional_Maps
+        (Key_Type                       => Cursor,
+         Element_Type                   => Positive_Count_Type,
+         Equivalent_Keys                => "=",
+         Enable_Handling_Of_Equivalence => False);
+
+      function "="
+        (Left  : P.Map;
+         Right : P.Map) return Boolean renames P."=";
+
+      function "<="
+        (Left  : P.Map;
+         Right : P.Map) return Boolean renames P."<=";
+
+      function Mapping_Preserved
+        (K_Left  : K.Sequence;
+         K_Right : K.Sequence;
+         P_Left  : P.Map;
+         P_Right : P.Map) return Boolean
+      with
+        Global => null,
+        Post   =>
+          (if Mapping_Preserved'Result then
+
+             --  Right contains all the cursors of Left
+
+             P.Keys_Included (P_Left, P_Right)
+
+               --  Right contains all the keys of Left
+
+               and K_Keys_Included (K_Left, K_Right)
+
+               --  Mappings from cursors to elements induced by K_Left, P_Left
+               --  and K_Right, P_Right are the same.
+
+               and (for all C of P_Left =>
+                     K.Get (K_Left, P.Get (P_Left, C)) =
+                     K.Get (K_Right, P.Get (P_Right, C))));
+
+      function Model (Container : Map) return M.Map with
+      --  The high-level model of a map is a map from keys to elements. Neither
+      --  cursors nor order of elements are represented in this model. Keys are
+      --  modeled up to equivalence.
+
+        Ghost,
+        Global => null;
+
+      function Keys (Container : Map) return K.Sequence with
+      --  The Keys sequence represents the underlying list structure of maps
+      --  that is used for iteration. It stores the actual values of keys in
+      --  the map. It does not model cursors nor elements.
+
+        Ghost,
+        Global => null,
+        Post   =>
+          K.Length (Keys'Result) = Length (Container)
+
+            --  It only contains keys contained in Model
+
+            and (for all Key of Keys'Result =>
+                  M.Has_Key (Model (Container), Key))
+
+            --  It contains all the keys contained in Model
+
+            and (for all Key of Model (Container) =>
+                  (Find (Keys'Result, Key) > 0
+                    and then Equivalent_Keys
+                               (K.Get (Keys'Result, Find (Keys'Result, Key)),
+                                Key)))
+
+            --  It has no duplicate
+
+            and (for all I in 1 .. Length (Container) =>
+                  Find (Keys'Result, K.Get (Keys'Result, I)) = I)
+
+            and (for all I in 1 .. Length (Container) =>
+                  (for all J in 1 .. Length (Container) =>
+                    (if Equivalent_Keys
+                          (K.Get (Keys'Result, I), K.Get (Keys'Result, J))
+                     then
+                        I = J)));
+      pragma Annotate (GNATprove, Iterable_For_Proof, "Model", Keys);
+
+      function Positions (Container : Map) return P.Map with
+      --  The Positions map is used to model cursors. It only contains valid
+      --  cursors and maps them to their position in the container.
+
+        Ghost,
+        Global => null,
+        Post   =>
+          not P.Has_Key (Positions'Result, No_Element)
+
+            --  Positions of cursors are smaller than the container's length
+
+            and then
+              (for all I of Positions'Result =>
+                P.Get (Positions'Result, I) in 1 .. Length (Container)
+
+            --  No two cursors have the same position. Note that we do not
+            --  state that there is a cursor in the map for each position, as
+            --  it is rarely needed.
+
+            and then
+              (for all J of Positions'Result =>
+                (if P.Get (Positions'Result, I) = P.Get (Positions'Result, J)
+                 then I = J)));
+
+      procedure Lift_Abstraction_Level (Container : Map) with
+        --  Lift_Abstraction_Level is a ghost procedure that does nothing but
+        --  assume that we can access the same elements by iterating over
+        --  positions or cursors.
+        --  This information is not generally useful except when switching from
+        --  a low-level, cursor-aware view of a container, to a high-level,
+        --  position-based view.
+
+        Ghost,
+        Global => null,
+        Post   =>
+          (for all Key of Keys (Container) =>
+            (for some I of Positions (Container) =>
+              K.Get (Keys (Container), P.Get (Positions (Container), I)) =
+                Key));
+
+      function Contains
+        (C : M.Map;
+         K : Key_Type) return Boolean renames M.Has_Key;
+      --  To improve readability of contracts, we rename the function used to
+      --  search for a key in the model to Contains.
+
+      function Element
+        (C : M.Map;
+         K : Key_Type) return Element_Type renames M.Get;
+      --  To improve readability of contracts, we rename the function used to
+      --  access an element in the model to Element.
+
+   end Formal_Model;
+   use Formal_Model;
+
+   function "=" (Left, Right : Map) return Boolean with
+     Global => null,
+     Post   => "="'Result = (Model (Left) = Model (Right));
+
+   function Capacity (Container : Map) return Count_Type with
+     Global => null,
+     Post   => Capacity'Result = Container.Capacity;
+
+   procedure Reserve_Capacity
+     (Container : in out Map;
+      Capacity  : Count_Type)
+   with
+     Global => null,
+     Pre    => Capacity <= Container.Capacity,
+     Post   =>
+       Model (Container) = Model (Container)'Old
+         and Length (Container)'Old = Length (Container)
+
+         --  Actual keys are preserved
+
+         and K_Keys_Included (Keys (Container), Keys (Container)'Old)
+         and K_Keys_Included (Keys (Container)'Old, Keys (Container));
+
+   function Is_Empty (Container : Map) return Boolean with
+     Global => null,
+     Post   => Is_Empty'Result = (Length (Container) = 0);
+
+   procedure Clear (Container : in out Map) with
+     Global => null,
+     Post   => Length (Container) = 0 and M.Is_Empty (Model (Container));
+
+   procedure Assign (Target : in out Map; Source : Map) with
+     Global => null,
+     Pre    => Target.Capacity >= Length (Source),
+     Post   =>
+       Model (Target) = Model (Source)
+         and Length (Source) = Length (Target)
+
+         --  Actual keys are preserved
+
+         and K_Keys_Included (Keys (Target), Keys (Source))
+         and K_Keys_Included (Keys (Source), Keys (Target));
+
+   function Copy
+     (Source   : Map;
+      Capacity : Count_Type := 0) return Map
+   with
+     Global => null,
+     Pre    => Capacity = 0 or else Capacity >= Source.Capacity,
+     Post   =>
+       Model (Copy'Result) = Model (Source)
+         and Keys (Copy'Result) = Keys (Source)
+         and Positions (Copy'Result) = Positions (Source)
+         and (if Capacity = 0 then
+                 Copy'Result.Capacity = Source.Capacity
+              else
+                 Copy'Result.Capacity = Capacity);
+   --  Copy returns a container stricty equal to Source. It must have the same
+   --  cursors associated with each element. Therefore:
+   --  - capacity=0 means use Source.Capacity as capacity of target
+   --  - the modulus cannot be changed.
+
+   function Key (Container : Map; Position : Cursor) return Key_Type with
+     Global => null,
+     Pre    => Has_Element (Container, Position),
+     Post   =>
+       Key'Result =
+         K.Get (Keys (Container), P.Get (Positions (Container), Position));
+   pragma Annotate (GNATprove, Inline_For_Proof, Key);
+
+   function Element
+     (Container : Map;
+      Position  : Cursor) return Element_Type
+   with
+     Global => null,
+     Pre    => Has_Element (Container, Position),
+     Post   =>
+       Element'Result = Element (Model (Container), Key (Container, Position));
+   pragma Annotate (GNATprove, Inline_For_Proof, Element);
+
+   procedure Replace_Element
+     (Container : in out Map;
+      Position  : Cursor;
+      New_Item  : Element_Type)
+   with
+     Global => null,
+     Pre    => Has_Element (Container, Position),
+     Post   =>
+
+       --  Order of keys and cursors is preserved
+
+       Keys (Container) = Keys (Container)'Old
+         and Positions (Container) = Positions (Container)'Old
+
+         --  New_Item is now associated with the key at position Position in
+         --  Container.
+
+         and Element (Container, Position) = New_Item
+
+         --  Elements associated with other keys are preserved
+
+         and M.Same_Keys (Model (Container), Model (Container)'Old)
+         and M.Elements_Equal_Except
+               (Model (Container),
+                Model (Container)'Old,
+                Key (Container, Position));
+
+   procedure Move (Target : in out Map; Source : in out Map) with
+     Global => null,
+     Pre    => Target.Capacity >= Length (Source),
+     Post   =>
+       Model (Target) = Model (Source)'Old
+         and Length (Source)'Old = Length (Target)
+         and Length (Source) = 0
+
+         --  Actual keys are preserved
+
+         and K_Keys_Included (Keys (Target), Keys (Source)'Old)
+         and K_Keys_Included (Keys (Source)'Old, Keys (Target));
+
+   procedure Insert
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type;
+      Position  : out Cursor;
+      Inserted  : out Boolean)
+   with
+     Global         => null,
+     Pre            =>
+       Length (Container) < Container.Capacity or Contains (Container, Key),
+     Post           =>
+       Contains (Container, Key)
+         and Has_Element (Container, Position)
+         and Equivalent_Keys
+               (Formal_Hashed_Maps.Key (Container, Position), Key),
+     Contract_Cases =>
+
+       --  If Key is already in Container, it is not modified and Inserted is
+       --  set to False.
+
+       (Contains (Container, Key) =>
+          not Inserted
+            and Model (Container) = Model (Container)'Old
+            and Keys (Container) = Keys (Container)'Old
+            and Positions (Container) = Positions (Container)'Old,
+
+        --  Otherwise, Key is inserted in Container and Inserted is set to True
+
+        others =>
+          Inserted
+            and Length (Container) = Length (Container)'Old + 1
+
+            --  Key now maps to New_Item
+
+            and Formal_Hashed_Maps.Key (Container, Position) = Key
+            and Element (Model (Container), Key) = New_Item
+
+            --  Other keys are preserved
+
+            and Model (Container)'Old <= Model (Container)
+            and M.Keys_Included_Except
+                  (Model (Container),
+                   Model (Container)'Old,
+                   Key)
+
+            --  Mapping from cursors to keys is preserved
+
+            and Mapping_Preserved
+                  (K_Left  => Keys (Container)'Old,
+                   K_Right => Keys (Container),
+                   P_Left  => Positions (Container)'Old,
+                   P_Right => Positions (Container))
+            and P.Keys_Included_Except
+                  (Positions (Container),
+                   Positions (Container)'Old,
+                   Position));
+
+   procedure Insert
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type)
+   with
+     Global => null,
+     Pre    =>
+       Length (Container) < Container.Capacity
+        and then (not Contains (Container, Key)),
+     Post   =>
+       Length (Container) = Length (Container)'Old + 1
+         and Contains (Container, Key)
+
+         --  Key now maps to New_Item
+
+         and Formal_Hashed_Maps.Key (Container, Find (Container, Key)) = Key
+         and Element (Model (Container), Key) = New_Item
+
+         --  Other keys are preserved
+
+         and Model (Container)'Old <= Model (Container)
+         and M.Keys_Included_Except
+               (Model (Container),
+                Model (Container)'Old,
+                Key)
+
+         --  Mapping from cursors to keys is preserved
+
+         and Mapping_Preserved
+               (K_Left  => Keys (Container)'Old,
+                K_Right => Keys (Container),
+                P_Left  => Positions (Container)'Old,
+                P_Right => Positions (Container))
+         and P.Keys_Included_Except
+               (Positions (Container),
+                Positions (Container)'Old,
+                Find (Container, Key));
+
+   procedure Include
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type)
+   with
+     Global         => null,
+     Pre            =>
+       Length (Container) < Container.Capacity or Contains (Container, Key),
+     Post           =>
+       Contains (Container, Key) and Element (Container, Key) = New_Item,
+     Contract_Cases =>
+
+       --  If Key is already in Container, Key is mapped to New_Item
+
+       (Contains (Container, Key) =>
+
+          --  Cursors are preserved
+
+          Positions (Container) = Positions (Container)'Old
+
+            --  The key equivalent to Key in Container is replaced by Key
+
+            and K.Get
+                  (Keys (Container),
+                   P.Get (Positions (Container), Find (Container, Key))) = Key
+            and K.Equal_Except
+                  (Keys (Container)'Old,
+                   Keys (Container),
+                   P.Get (Positions (Container), Find (Container, Key)))
+
+            --  Elements associated with other keys are preserved
+
+            and M.Same_Keys (Model (Container), Model (Container)'Old)
+            and M.Elements_Equal_Except
+                  (Model (Container),
+                   Model (Container)'Old,
+                   Key),
+
+        --  Otherwise, Key is inserted in Container
+
+        others =>
+          Length (Container) = Length (Container)'Old + 1
+
+            --  Other keys are preserved
+
+            and Model (Container)'Old <= Model (Container)
+            and M.Keys_Included_Except
+                  (Model (Container),
+                   Model (Container)'Old,
+                   Key)
+
+            --  Key is inserted in Container
+
+            and K.Get
+                  (Keys (Container),
+                   P.Get (Positions (Container), Find (Container, Key))) = Key
+
+            --  Mapping from cursors to keys is preserved
+
+            and Mapping_Preserved
+                  (K_Left  => Keys (Container)'Old,
+                   K_Right => Keys (Container),
+                   P_Left  => Positions (Container)'Old,
+                   P_Right => Positions (Container))
+            and P.Keys_Included_Except
+                  (Positions (Container),
+                   Positions (Container)'Old,
+                   Find (Container, Key)));
+
+   procedure Replace
+     (Container : in out Map;
+      Key       : Key_Type;
+      New_Item  : Element_Type)
+   with
+     Global => null,
+     Pre    => Contains (Container, Key),
+     Post   =>
+
+       --  Cursors are preserved
+
+       Positions (Container) = Positions (Container)'Old
+
+         --  The key equivalent to Key in Container is replaced by Key
+
+         and K.Get
+               (Keys (Container),
+                P.Get (Positions (Container), Find (Container, Key))) = Key
+         and K.Equal_Except
+               (Keys (Container)'Old,
+                Keys (Container),
+                P.Get (Positions (Container), Find (Container, Key)))
+
+         --  New_Item is now associated with the Key in Container
+
+         and Element (Model (Container), Key) = New_Item
+
+         --  Elements associated with other keys are preserved
+
+         and M.Same_Keys (Model (Container), Model (Container)'Old)
+         and M.Elements_Equal_Except
+               (Model (Container),
+                Model (Container)'Old,
+                Key);
+
+   procedure Exclude (Container : in out Map; Key : Key_Type) with
+     Global         => null,
+     Post           => not Contains (Container, Key),
+     Contract_Cases =>
+
+       --  If Key is not in Container, nothing is changed
+
+       (not Contains (Container, Key) =>
+          Model (Container) = Model (Container)'Old
+            and Keys (Container) = Keys (Container)'Old
+            and Positions (Container) = Positions (Container)'Old,
+
+        --  Otherwise, Key is removed from Container
+
+        others =>
+          Length (Container) = Length (Container)'Old - 1
+
+            --  Other keys are preserved
+
+            and Model (Container) <= Model (Container)'Old
+            and M.Keys_Included_Except
+                  (Model (Container)'Old,
+                   Model (Container),
+                   Key)
+
+            --  Mapping from cursors to keys is preserved
+
+            and Mapping_Preserved
+                  (K_Left  => Keys (Container),
+                   K_Right => Keys (Container)'Old,
+                   P_Left  => Positions (Container),
+                   P_Right => Positions (Container)'Old)
+            and P.Keys_Included_Except
+                  (Positions (Container)'Old,
+                   Positions (Container),
+                   Find (Container, Key)'Old));
+
+   procedure Delete (Container : in out Map; Key : Key_Type) with
+     Global => null,
+     Pre    => Contains (Container, Key),
+     Post   =>
+       Length (Container) = Length (Container)'Old - 1
+
+         --  Key is no longer in Container
+
+         and not Contains (Container, Key)
+
+         --  Other keys are preserved
+
+         and Model (Container) <= Model (Container)'Old
+         and M.Keys_Included_Except
+               (Model (Container)'Old,
+                Model (Container),
+                Key)
+
+         --  Mapping from cursors to keys is preserved
+
+         and Mapping_Preserved
+               (K_Left  => Keys (Container),
+                K_Right => Keys (Container)'Old,
+                P_Left  => Positions (Container),
+                P_Right => Positions (Container)'Old)
+         and P.Keys_Included_Except
+               (Positions (Container)'Old,
+                Positions (Container),
+                Find (Container, Key)'Old);
+
+   procedure Delete (Container : in out Map; Position : in out Cursor) with
+     Global => null,
+     Pre    => Has_Element (Container, Position),
+     Post   =>
+       Position = No_Element
+         and Length (Container) = Length (Container)'Old - 1
+
+         --  The key at position Position is no longer in Container
+
+         and not Contains (Container, Key (Container, Position)'Old)
+         and not P.Has_Key (Positions (Container), Position'Old)
+
+         --  Other keys are preserved
+
+         and Model (Container) <= Model (Container)'Old
+         and M.Keys_Included_Except
+               (Model (Container)'Old,
+                Model (Container),
+                Key (Container, Position)'Old)
+
+         --  Mapping from cursors to keys is preserved
+
+         and Mapping_Preserved
+               (K_Left  => Keys (Container),
+                K_Right => Keys (Container)'Old,
+                P_Left  => Positions (Container),
+                P_Right => Positions (Container)'Old)
+         and P.Keys_Included_Except
+               (Positions (Container)'Old,
+                Positions (Container),
+                Position'Old);
+
+   function First (Container : Map) return Cursor with
+     Global         => null,
+     Contract_Cases =>
+       (Length (Container) = 0 =>
+          First'Result = No_Element,
+
+        others =>
+          Has_Element (Container, First'Result)
+            and P.Get (Positions (Container), First'Result) = 1);
+
+   function Next (Container : Map; Position : Cursor) return Cursor with
+     Global         => null,
+     Pre            =>
+       Has_Element (Container, Position) or else Position = No_Element,
+     Contract_Cases =>
+       (Position = No_Element
+          or else P.Get (Positions (Container), Position) = Length (Container)
+        =>
+          Next'Result = No_Element,
+
+        others =>
+          Has_Element (Container, Next'Result)
+            and then P.Get (Positions (Container), Next'Result) =
+                     P.Get (Positions (Container), Position) + 1);
+
+   procedure Next (Container : Map; Position : in out Cursor) with
+     Global         => null,
+     Pre            =>
+       Has_Element (Container, Position) or else Position = No_Element,
+     Contract_Cases =>
+       (Position = No_Element
+          or else P.Get (Positions (Container), Position) = Length (Container)
+        =>
+          Position = No_Element,
+
+        others =>
+          Has_Element (Container, Position)
+            and then P.Get (Positions (Container), Position) =
+                     P.Get (Positions (Container), Position'Old) + 1);
+
+   function Find (Container : Map; Key : Key_Type) return Cursor with
+     Global         => null,
+     Contract_Cases =>
+
+       --  If Key is not contained in Container, Find returns No_Element
+
+       (not Contains (Model (Container), Key) =>
+          Find'Result = No_Element,
+
+        --  Otherwise, Find returns a valid cursor in Container
+
+        others =>
+          P.Has_Key (Positions (Container), Find'Result)
+            and P.Get (Positions (Container), Find'Result) =
+                Find (Keys (Container), Key)
+
+            --  The key designated by the result of Find is Key
+
+            and Equivalent_Keys
+                  (Formal_Hashed_Maps.Key (Container, Find'Result), Key));
+
+   function Contains (Container : Map; Key : Key_Type) return Boolean with
+     Global => null,
+     Post   => Contains'Result = Contains (Model (Container), Key);
+   pragma Annotate (GNATprove, Inline_For_Proof, Contains);
+
+   function Element (Container : Map; Key : Key_Type) return Element_Type with
+     Global => null,
+     Pre    => Contains (Container, Key),
+     Post   => Element'Result = Element (Model (Container), Key);
+   pragma Annotate (GNATprove, Inline_For_Proof, Element);
+
+   function Has_Element (Container : Map; Position : Cursor) return Boolean
+   with
+     Global => null,
+     Post   =>
+       Has_Element'Result = P.Has_Key (Positions (Container), Position);
+   pragma Annotate (GNATprove, Inline_For_Proof, Has_Element);
+
+   function Default_Modulus (Capacity : Count_Type) return Hash_Type with
+     Global => null;
+
+private
+   pragma SPARK_Mode (Off);
+
+   pragma Inline (Length);
+   pragma Inline (Is_Empty);
+   pragma Inline (Clear);
+   pragma Inline (Key);
+   pragma Inline (Element);
+   pragma Inline (Contains);
+   pragma Inline (Capacity);
+   pragma Inline (Has_Element);
+   pragma Inline (Equivalent_Keys);
+   pragma Inline (Next);
+
+   type Node_Type is record
+      Key         : Key_Type;
+      Element     : Element_Type;
+      Next        : Count_Type;
+      Has_Element : Boolean := False;
+   end record;
+
+   package HT_Types is new
+     Ada.Containers.Hash_Tables.Generic_Bounded_Hash_Table_Types (Node_Type);
+
+   type Map (Capacity : Count_Type; Modulus : Hash_Type) is
+     new HT_Types.Hash_Table_Type (Capacity, Modulus) with null record;
+
+   Empty_Map : constant Map := (Capacity => 0, Modulus => 0, others => <>);
+
+end Ada.Containers.Formal_Hashed_Maps;