------------------------------------------------------------------------------
-- --
-- GNAT LIBRARY COMPONENTS --
-- --
-- ADA.CONTAINERS.FORMAL_DOUBLY_LINKED_LISTS --
-- --
-- S p e c --
-- --
-- Copyright (C) 2004-2013, 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 Ada.Containers.Bounded_Doubly_Linked_Lists in the
-- Ada 2012 RM. The modifications are to facilitate formal proofs by making it
-- easier to express properties.
-- The modifications are:
-- A parameter for the container is added to every function reading the
-- contents of a container: Next, Previous, Query_Element, Has_Element,
-- Iterate, Reverse_Iterate, Element. 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.
-- There are three new functions:
-- function Strict_Equal (Left, Right : List) return Boolean;
-- function Left (Container : List; Position : Cursor) return List;
-- function Right (Container : List; Position : Cursor) return List;
-- See subprogram specifications that follow for details
generic
type Element_Type is private;
with function "=" (Left, Right : Element_Type)
return Boolean is <>;
package Ada.Containers.Formal_Doubly_Linked_Lists is
pragma Pure;
type List (Capacity : Count_Type) is private;
pragma Preelaborable_Initialization (List);
type Cursor is private;
pragma Preelaborable_Initialization (Cursor);
Empty_List : constant List;
No_Element : constant Cursor;
function "=" (Left, Right : List) return Boolean;
function Length (Container : List) return Count_Type;
function Is_Empty (Container : List) return Boolean;
procedure Clear (Container : in out List);
procedure Assign (Target : in out List; Source : List) with
Pre => Target.Capacity >= Length (Source);
function Copy (Source : List; Capacity : Count_Type := 0) return List;
function Element
(Container : List;
Position : Cursor) return Element_Type
with
Pre => Has_Element (Container, Position);
procedure Replace_Element
(Container : in out List;
Position : Cursor;
New_Item : Element_Type)
with
Pre => Has_Element (Container, Position);
procedure Move (Target : in out List; Source : in out List) with
Pre => Target.Capacity >= Length (Source);
procedure Insert
(Container : in out List;
Before : Cursor;
New_Item : Element_Type;
Count : Count_Type := 1)
with
Pre => Length (Container) + Count <= Container.Capacity
and then (Has_Element (Container, Before)
or else Before = No_Element);
procedure Insert
(Container : in out List;
Before : Cursor;
New_Item : Element_Type;
Position : out Cursor;
Count : Count_Type := 1)
with
Pre => Length (Container) + Count <= Container.Capacity
and then (Has_Element (Container, Before)
or else Before = No_Element);
procedure Insert
(Container : in out List;
Before : Cursor;
Position : out Cursor;
Count : Count_Type := 1)
with
Pre => Length (Container) + Count <= Container.Capacity
and then (Has_Element (Container, Before)
or else Before = No_Element);
procedure Prepend
(Container : in out List;
New_Item : Element_Type;
Count : Count_Type := 1)
with
Pre => Length (Container) + Count <= Container.Capacity;
procedure Append
(Container : in out List;
New_Item : Element_Type;
Count : Count_Type := 1)
with
Pre => Length (Container) + Count <= Container.Capacity;
procedure Delete
(Container : in out List;
Position : in out Cursor;
Count : Count_Type := 1)
with
Pre => Has_Element (Container, Position);
procedure Delete_First
(Container : in out List;
Count : Count_Type := 1);
procedure Delete_Last
(Container : in out List;
Count : Count_Type := 1);
procedure Reverse_Elements (Container : in out List);
procedure Swap
(Container : in out List;
I, J : Cursor)
with
Pre => Has_Element (Container, I) and then Has_Element (Container, J);
procedure Swap_Links
(Container : in out List;
I, J : Cursor)
with
Pre => Has_Element (Container, I) and then Has_Element (Container, J);
procedure Splice
(Target : in out List;
Before : Cursor;
Source : in out List)
with
Pre => Length (Source) + Length (Target) <= Target.Capacity
and then (Has_Element (Target, Before)
or else Before = No_Element);
procedure Splice
(Target : in out List;
Before : Cursor;
Source : in out List;
Position : in out Cursor)
with
Pre => Length (Source) + Length (Target) <= Target.Capacity
and then (Has_Element (Target, Before)
or else Before = No_Element)
and then Has_Element (Source, Position);
procedure Splice
(Container : in out List;
Before : Cursor;
Position : Cursor)
with
Pre => 2 * Length (Container) <= Container.Capacity
and then (Has_Element (Container, Before)
or else Before = No_Element)
and then Has_Element (Container, Position);
function First (Container : List) return Cursor;
function First_Element (Container : List) return Element_Type with
Pre => not Is_Empty (Container);
function Last (Container : List) return Cursor;
function Last_Element (Container : List) return Element_Type with
Pre => not Is_Empty (Container);
function Next (Container : List; Position : Cursor) return Cursor with
Pre => Has_Element (Container, Position) or else Position = No_Element;
procedure Next (Container : List; Position : in out Cursor) with
Pre => Has_Element (Container, Position) or else Position = No_Element;
function Previous (Container : List; Position : Cursor) return Cursor with
Pre => Has_Element (Container, Position) or else Position = No_Element;
procedure Previous (Container : List; Position : in out Cursor) with
Pre => Has_Element (Container, Position) or else Position = No_Element;
function Find
(Container : List;
Item : Element_Type;
Position : Cursor := No_Element) return Cursor
with
Pre => Has_Element (Container, Position) or else Position = No_Element;
function Reverse_Find
(Container : List;
Item : Element_Type;
Position : Cursor := No_Element) return Cursor
with
Pre => Has_Element (Container, Position) or else Position = No_Element;
function Contains
(Container : List;
Item : Element_Type) return Boolean;
function Has_Element (Container : List; Position : Cursor) return Boolean;
generic
with function "<" (Left, Right : Element_Type) return Boolean is <>;
package Generic_Sorting is
function Is_Sorted (Container : List) return Boolean;
procedure Sort (Container : in out List);
procedure Merge (Target, Source : in out List);
end Generic_Sorting;
function Strict_Equal (Left, Right : List) return Boolean;
-- Strict_Equal returns True if the containers are physically equal, i.e.
-- they are structurally equal (function "=" returns True) and that they
-- have the same set of cursors.
function Left (Container : List; Position : Cursor) return List with
Pre => Has_Element (Container, Position) or else Position = No_Element;
function Right (Container : List; Position : Cursor) return List with
Pre => Has_Element (Container, Position) or else Position = No_Element;
-- Left returns a container containing all elements preceding Position
-- (excluded) in Container. Right returns a container containing all
-- elements following Position (included) in Container. These two new
-- functions can be used to express invariant properties in loops which
-- iterate over containers. Left returns the part of the container already
-- scanned and Right the part not scanned yet.
private
type Node_Type is record
Prev : Count_Type'Base := -1;
Next : Count_Type;
Element : Element_Type;
end record;
function "=" (L, R : Node_Type) return Boolean is abstract;
type Node_Array is array (Count_Type range <>) of Node_Type;
function "=" (L, R : Node_Array) return Boolean is abstract;
type List (Capacity : Count_Type) is tagged record
Nodes : Node_Array (1 .. Capacity) := (others => <>);
Free : Count_Type'Base := -1;
Length : Count_Type := 0;
First : Count_Type := 0;
Last : Count_Type := 0;
end record;
type Cursor is record
Node : Count_Type := 0;
end record;
Empty_List : constant List := (0, others => <>);
No_Element : constant Cursor := (Node => 0);
end Ada.Containers.Formal_Doubly_Linked_Lists;