| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT LIBRARY COMPONENTS -- |
| -- -- |
| -- ADA.CONTAINERS.FORMAL_DOUBLY_LINKED_LISTS -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 2004-2015, 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 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: 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 First_To_Previous (Container : List; Current : Cursor) |
| -- return List; |
| -- function Current_To_Last (Container : List; Current : 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 with |
| Pure, |
| SPARK_Mode |
| is |
| pragma Annotate (GNATprove, External_Axiomatization); |
| |
| type List (Capacity : Count_Type) is private with |
| Iterable => (First => First, |
| Next => Next, |
| Has_Element => Has_Element, |
| Element => Element), |
| Default_Initial_Condition => Is_Empty (List); |
| 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 with |
| Global => null; |
| |
| function Length (Container : List) return Count_Type with |
| Global => null; |
| |
| function Is_Empty (Container : List) return Boolean with |
| Global => null; |
| |
| procedure Clear (Container : in out List) with |
| Global => null; |
| |
| procedure Assign (Target : in out List; Source : List) with |
| Global => null, |
| Pre => Target.Capacity >= Length (Source); |
| |
| function Copy (Source : List; Capacity : Count_Type := 0) return List with |
| Global => null, |
| Pre => Capacity = 0 or else Capacity >= Source.Capacity; |
| |
| function Element |
| (Container : List; |
| Position : Cursor) return Element_Type |
| with |
| Global => null, |
| Pre => Has_Element (Container, Position); |
| |
| procedure Replace_Element |
| (Container : in out List; |
| Position : Cursor; |
| New_Item : Element_Type) |
| with |
| Global => null, |
| Pre => Has_Element (Container, Position); |
| |
| procedure Move (Target : in out List; Source : in out List) with |
| Global => null, |
| Pre => Target.Capacity >= Length (Source); |
| |
| procedure Insert |
| (Container : in out List; |
| Before : Cursor; |
| New_Item : Element_Type; |
| Count : Count_Type := 1) |
| with |
| Global => null, |
| 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 |
| Global => null, |
| 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 |
| Global => null, |
| 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 |
| Global => null, |
| Pre => Length (Container) + Count <= Container.Capacity; |
| |
| procedure Append |
| (Container : in out List; |
| New_Item : Element_Type; |
| Count : Count_Type := 1) |
| with |
| Global => null, |
| Pre => Length (Container) + Count <= Container.Capacity; |
| |
| procedure Delete |
| (Container : in out List; |
| Position : in out Cursor; |
| Count : Count_Type := 1) |
| with |
| Global => null, |
| Pre => Has_Element (Container, Position); |
| |
| procedure Delete_First |
| (Container : in out List; |
| Count : Count_Type := 1) |
| with |
| Global => null; |
| |
| procedure Delete_Last |
| (Container : in out List; |
| Count : Count_Type := 1) |
| with |
| Global => null; |
| |
| procedure Reverse_Elements (Container : in out List) with |
| Global => null; |
| |
| procedure Swap |
| (Container : in out List; |
| I, J : Cursor) |
| with |
| Global => null, |
| Pre => Has_Element (Container, I) and then Has_Element (Container, J); |
| |
| procedure Swap_Links |
| (Container : in out List; |
| I, J : Cursor) |
| with |
| Global => null, |
| Pre => Has_Element (Container, I) and then Has_Element (Container, J); |
| |
| procedure Splice |
| (Target : in out List; |
| Before : Cursor; |
| Source : in out List) |
| with |
| Global => null, |
| 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 |
| Global => null, |
| 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 |
| Global => null, |
| 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 with |
| Global => null; |
| |
| function First_Element (Container : List) return Element_Type with |
| Global => null, |
| Pre => not Is_Empty (Container); |
| |
| function Last (Container : List) return Cursor with |
| Global => null; |
| |
| function Last_Element (Container : List) return Element_Type with |
| Global => null, |
| Pre => not Is_Empty (Container); |
| |
| function Next (Container : List; Position : Cursor) return Cursor with |
| Global => null, |
| Pre => Has_Element (Container, Position) or else Position = No_Element; |
| |
| procedure Next (Container : List; Position : in out Cursor) with |
| Global => null, |
| Pre => Has_Element (Container, Position) or else Position = No_Element; |
| |
| function Previous (Container : List; Position : Cursor) return Cursor with |
| Global => null, |
| Pre => Has_Element (Container, Position) or else Position = No_Element; |
| |
| procedure Previous (Container : List; Position : in out Cursor) with |
| Global => null, |
| Pre => Has_Element (Container, Position) or else Position = No_Element; |
| |
| function Find |
| (Container : List; |
| Item : Element_Type; |
| Position : Cursor := No_Element) return Cursor |
| with |
| Global => null, |
| 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 |
| Global => null, |
| Pre => Has_Element (Container, Position) or else Position = No_Element; |
| |
| function Contains |
| (Container : List; |
| Item : Element_Type) return Boolean |
| with |
| Global => null; |
| |
| function Has_Element (Container : List; Position : Cursor) return Boolean |
| with |
| Global => null; |
| |
| generic |
| with function "<" (Left, Right : Element_Type) return Boolean is <>; |
| package Generic_Sorting is |
| |
| function Is_Sorted (Container : List) return Boolean with |
| Global => null; |
| |
| procedure Sort (Container : in out List) with |
| Global => null; |
| |
| procedure Merge (Target, Source : in out List) with |
| Global => null; |
| |
| end Generic_Sorting; |
| |
| function Strict_Equal (Left, Right : List) return Boolean with |
| Ghost, |
| Global => null; |
| -- 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 First_To_Previous (Container : List; Current : Cursor) return List |
| with |
| Ghost, |
| Global => null, |
| Pre => Has_Element (Container, Current) or else Current = No_Element; |
| |
| function Current_To_Last (Container : List; Current : Cursor) return List |
| with |
| Ghost, |
| Global => null, |
| Pre => Has_Element (Container, Current) or else Current = No_Element; |
| -- First_To_Previous returns a container containing all elements preceding |
| -- Current (excluded) in Container. Current_To_Last returns a container |
| -- containing all elements following Current (included) in Container. |
| -- These two new functions can be used to express invariant properties in |
| -- loops which iterate over containers. First_To_Previous returns the part |
| -- of the container already scanned and Current_To_Last the part not |
| -- scanned yet. |
| |
| private |
| pragma SPARK_Mode (Off); |
| |
| 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; |
