------------------------------------------------------------------------------ -- -- -- GNAT LIBRARY COMPONENTS -- -- -- -- A D A . C O N T A I N E R S . F O R M A L _ V E C T O R S -- -- -- -- 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 -- -- . -- ------------------------------------------------------------------------------ -- This spec is derived from package Ada.Containers.Bounded_Vectors 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. generic type Index_Type is range <>; type Element_Type is private; with function "=" (Left, Right : Element_Type) return Boolean is <>; Bounded : Boolean := True; -- If True, the containers are bounded; the initial capacity is the maximum -- size, and heap allocation will be avoided. If False, the containers can -- grow via heap allocation. package Ada.Containers.Formal_Vectors with SPARK_Mode is pragma Annotate (GNATprove, External_Axiomatization); pragma Annotate (CodePeer, Skip_Analysis); subtype Extended_Index is Index_Type'Base range Index_Type'First - 1 .. Index_Type'Min (Index_Type'Base'Last - 1, Index_Type'Last) + 1; No_Index : constant Extended_Index := Extended_Index'First; subtype Capacity_Range is Count_Type range 0 .. Count_Type (Index_Type'Last - Index_Type'First + 1); type Vector (Capacity : Capacity_Range) is limited private with Default_Initial_Condition => Is_Empty (Vector); -- In the bounded case, Capacity is the capacity of the container, which -- never changes. In the unbounded case, Capacity is the initial capacity -- of the container, and operations such as Reserve_Capacity and Append can -- increase the capacity. The capacity never shrinks, except in the case of -- Clear. -- -- Note that all objects of type Vector are constrained, including in the -- unbounded case; you can't assign from one object to another if the -- Capacity is different. function Empty_Vector return Vector; function "=" (Left, Right : Vector) return Boolean with Global => null; function To_Vector (New_Item : Element_Type; Length : Capacity_Range) return Vector with Global => null; function Capacity (Container : Vector) return Capacity_Range with Global => null, Post => Capacity'Result >= Container.Capacity; procedure Reserve_Capacity (Container : in out Vector; Capacity : Capacity_Range) with Global => null, Pre => (if Bounded then Capacity <= Container.Capacity); function Length (Container : Vector) return Capacity_Range with Global => null; function Is_Empty (Container : Vector) return Boolean with Global => null; procedure Clear (Container : in out Vector) with Global => null; -- Note that this reclaims storage in the unbounded case. You need to call -- this before a container goes out of scope in order to avoid storage -- leaks. In addition, "X := ..." can leak unless you Clear(X) first. procedure Assign (Target : in out Vector; Source : Vector) with Global => null, Pre => (if Bounded then Length (Source) <= Target.Capacity); function Copy (Source : Vector; Capacity : Capacity_Range := 0) return Vector with Global => null, Pre => (if Bounded then (Capacity = 0 or Length (Source) <= Capacity)); function Element (Container : Vector; Index : Index_Type) return Element_Type with Global => null, Pre => Index in First_Index (Container) .. Last_Index (Container); procedure Replace_Element (Container : in out Vector; Index : Index_Type; New_Item : Element_Type) with Global => null, Pre => Index in First_Index (Container) .. Last_Index (Container); procedure Append (Container : in out Vector; New_Item : Vector) with Global => null, Pre => (if Bounded then Length (Container) + Length (New_Item) <= Container.Capacity); procedure Append (Container : in out Vector; New_Item : Element_Type) with Global => null, Pre => (if Bounded then Length (Container) < Container.Capacity); procedure Delete_Last (Container : in out Vector) with Global => null; procedure Reverse_Elements (Container : in out Vector) with Global => null; procedure Swap (Container : in out Vector; I, J : Index_Type) with Global => null, Pre => I in First_Index (Container) .. Last_Index (Container) and then J in First_Index (Container) .. Last_Index (Container); function First_Index (Container : Vector) return Index_Type with Global => null; function First_Element (Container : Vector) return Element_Type with Global => null, Pre => not Is_Empty (Container); function Last_Index (Container : Vector) return Extended_Index with Global => null; function Last_Element (Container : Vector) return Element_Type with Global => null, Pre => not Is_Empty (Container); function Find_Index (Container : Vector; Item : Element_Type; Index : Index_Type := Index_Type'First) return Extended_Index with Global => null; function Reverse_Find_Index (Container : Vector; Item : Element_Type; Index : Index_Type := Index_Type'Last) return Extended_Index with Global => null; function Contains (Container : Vector; Item : Element_Type) return Boolean with Global => null; function Has_Element (Container : Vector; Position : Extended_Index) return Boolean with Global => null; generic with function "<" (Left, Right : Element_Type) return Boolean is <>; package Generic_Sorting with SPARK_Mode is function Is_Sorted (Container : Vector) return Boolean with Global => null; procedure Sort (Container : in out Vector) with Global => null; end Generic_Sorting; function First_To_Previous (Container : Vector; Current : Index_Type) return Vector with Ghost, Global => null, Pre => Current in First_Index (Container) .. Last_Index (Container); function Current_To_Last (Container : Vector; Current : Index_Type) return Vector with Ghost, Global => null, Pre => Current in First_Index (Container) .. Last_Index (Container); -- 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); pragma Inline (First_Index); pragma Inline (Last_Index); pragma Inline (Element); pragma Inline (First_Element); pragma Inline (Last_Element); pragma Inline (Replace_Element); pragma Inline (Contains); subtype Array_Index is Capacity_Range range 1 .. Capacity_Range'Last; type Elements_Array is array (Array_Index range <>) of Element_Type; function "=" (L, R : Elements_Array) return Boolean is abstract; type Elements_Array_Ptr is access all Elements_Array; type Vector (Capacity : Capacity_Range) is limited record -- In the bounded case, the elements are stored in Elements. In the -- unbounded case, the elements are initially stored in Elements, until -- we run out of room, then we switch to Elements_Ptr. Last : Extended_Index := No_Index; Elements_Ptr : Elements_Array_Ptr := null; Elements : aliased Elements_Array (1 .. Capacity); end record; -- The primary reason Vector is limited is that in the unbounded case, once -- Elements_Ptr is in use, assignment statements won't work. "X := Y;" will -- cause X and Y to share state; that is, X.Elements_Ptr = Y.Elements_Ptr, -- so for example "Append (X, ...);" will modify BOTH X and Y. That would -- allow SPARK to "prove" things that are false. We could fix that by -- making Vector a controlled type, and override Adjust to make a deep -- copy, but finalization is not allowed in SPARK. -- -- Note that (unfortunately) this means that 'Old and 'Loop_Entry are not -- allowed on Vectors. function Empty_Vector return Vector is ((Capacity => 0, others => <>)); end Ada.Containers.Formal_Vectors;