------------------------------------------------------------------------------
--                                                                          --
--                         GNAT LIBRARY COMPONENTS                          --
--                                                                          --
--                A D A . C O N T A I N E R S . V E C T O R S               --
--                                                                          --
--                                 S p e c                                  --
--                                                                          --
--          Copyright (C) 2004-2018, 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.               --
--                                                                          --
-- In particular,  you can freely  distribute your programs  built with the --
-- GNAT Pro compiler, including any required library run-time units,  using --
-- any licensing terms  of your choosing.  See the AdaCore Software License --
-- for full details.                                                        --
--                                                                          --
-- This unit was originally developed by Matthew J Heaney.                  --
------------------------------------------------------------------------------

with Ada.Iterator_Interfaces;

with Ada.Containers.Helpers;
private with Ada.Finalization;
private with Ada.Streams;

generic
   type Index_Type is range <>;
   type Element_Type is private;

   with function "=" (Left, Right : Element_Type) return Boolean is <>;

package Vectors is

   type Hash_Type is mod 2**32;
   type Count_Type is range 0 .. 2**31 - 1;

   Capacity_Error : exception;

   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;

   type Vector is tagged private
   with
      Constant_Indexing => Constant_Reference,
      Variable_Indexing => Reference,
      Default_Iterator  => Iterate,
      Iterator_Element  => Element_Type;

   type Cursor is private;

   No_Element : constant Cursor;

   function Has_Element (Position : Cursor) return Boolean;

   package Vector_Iterator_Interfaces is new
      Ada.Iterator_Interfaces (Cursor, Has_Element);

   Empty_Vector : constant Vector;

   overriding function "=" (Left, Right : Vector) return Boolean;

   function To_Vector (Length : Count_Type) return Vector;

   function To_Vector
     (New_Item : Element_Type;
      Length   : Count_Type) return Vector;

   function "&" (Left, Right : Vector) return Vector;

   function "&" (Left : Vector; Right : Element_Type) return Vector;

   function "&" (Left : Element_Type; Right : Vector) return Vector;

   function "&" (Left, Right : Element_Type) return Vector;

   function Capacity (Container : Vector) return Count_Type;

   procedure Reserve_Capacity
     (Container : in out Vector;
      Capacity  : Count_Type);

   function Length (Container : Vector) return Count_Type;

   procedure Set_Length
     (Container : in out Vector;
      Length    : Count_Type);

   function Is_Empty (Container : Vector) return Boolean;

   procedure Clear (Container : in out Vector);

   function To_Cursor
     (Container : Vector;
      Index     : Extended_Index) return Cursor;

   function To_Index (Position : Cursor) return Extended_Index;

   function Element
     (Container : Vector;
      Index     : Index_Type) return Element_Type;

   function Element (Position : Cursor) return Element_Type;

   procedure Replace_Element
     (Container : in out Vector;
      Index     : Index_Type;
      New_Item  : Element_Type);

   procedure Replace_Element
     (Container : in out Vector;
      Position  : Cursor;
      New_Item  : Element_Type);

   procedure Query_Element
     (Container : Vector;
      Index     : Index_Type;
      Process   : not null access procedure (Element : Element_Type));

   procedure Query_Element
     (Position : Cursor;
      Process  : not null access procedure (Element : Element_Type));

   procedure Update_Element
     (Container : in out Vector;
      Index     : Index_Type;
      Process   : not null access procedure (Element : in out Element_Type));

   procedure Update_Element
     (Container : in out Vector;
      Position  : Cursor;
      Process   : not null access procedure (Element : in out Element_Type));

   type Constant_Reference_Type
      (Element : not null access constant Element_Type) is
   private
   with
      Implicit_Dereference => Element;

   type Reference_Type (Element : not null access Element_Type) is private
   with
      Implicit_Dereference => Element;

   function Constant_Reference
     (Container : aliased Vector;
      Position  : Cursor) return Constant_Reference_Type;
   pragma Inline (Constant_Reference);

   function Reference
     (Container : aliased in out Vector;
      Position  : Cursor) return Reference_Type;
   pragma Inline (Reference);

   function Constant_Reference
     (Container : aliased Vector;
      Index     : Index_Type) return Constant_Reference_Type;
   pragma Inline (Constant_Reference);

   function Reference
     (Container : aliased in out Vector;
      Index     : Index_Type) return Reference_Type;
   pragma Inline (Reference);

   procedure Assign (Target : in out Vector; Source : Vector);

   function Copy (Source : Vector; Capacity : Count_Type := 0) return Vector;

   procedure Move (Target : in out Vector; Source : in out Vector);

   procedure Insert
     (Container : in out Vector;
      Before    : Extended_Index;
      New_Item  : Vector);

   procedure Insert
     (Container : in out Vector;
      Before    : Cursor;
      New_Item  : Vector);

   procedure Insert
     (Container : in out Vector;
      Before    : Cursor;
      New_Item  : Vector;
      Position  : out Cursor);

   procedure Insert
     (Container : in out Vector;
      Before    : Extended_Index;
      New_Item  : Element_Type;
      Count     : Count_Type := 1);

   procedure Insert
     (Container : in out Vector;
      Before    : Cursor;
      New_Item  : Element_Type;
      Count     : Count_Type := 1);

   procedure Insert
     (Container : in out Vector;
      Before    : Cursor;
      New_Item  : Element_Type;
      Position  : out Cursor;
      Count     : Count_Type := 1);

   procedure Insert
     (Container : in out Vector;
      Before    : Extended_Index;
      Count     : Count_Type := 1);

   procedure Insert
     (Container : in out Vector;
      Before    : Cursor;
      Position  : out Cursor;
      Count     : Count_Type := 1);

   procedure Prepend
     (Container : in out Vector;
      New_Item  : Vector);

   procedure Prepend
     (Container : in out Vector;
      New_Item  : Element_Type;
      Count     : Count_Type := 1);

   procedure Append
     (Container : in out Vector;
      New_Item  : Vector);

   procedure Append
     (Container : in out Vector;
      New_Item  : Element_Type;
      Count     : Count_Type := 1);

   procedure Insert_Space
     (Container : in out Vector;
      Before    : Extended_Index;
      Count     : Count_Type := 1);

   procedure Insert_Space
     (Container : in out Vector;
      Before    : Cursor;
      Position  : out Cursor;
      Count     : Count_Type := 1);

   procedure Delete
     (Container : in out Vector;
      Index     : Extended_Index;
      Count     : Count_Type := 1);

   procedure Delete
     (Container : in out Vector;
      Position  : in out Cursor;
      Count     : Count_Type := 1);

   procedure Delete_First
     (Container : in out Vector;
      Count     : Count_Type := 1);

   procedure Delete_Last
     (Container : in out Vector;
      Count     : Count_Type := 1);

   procedure Reverse_Elements (Container : in out Vector);

   procedure Swap (Container : in out Vector; I, J : Index_Type);

   procedure Swap (Container : in out Vector; I, J : Cursor);

   function First_Index (Container : Vector) return Index_Type;

   function First (Container : Vector) return Cursor;

   function First_Element (Container : Vector) return Element_Type;

   function Last_Index (Container : Vector) return Extended_Index;

   function Last (Container : Vector) return Cursor;

   function Last_Element (Container : Vector) return Element_Type;

   function Next (Position : Cursor) return Cursor;

   procedure Next (Position : in out Cursor);

   function Previous (Position : Cursor) return Cursor;

   procedure Previous (Position : in out Cursor);

   function Find_Index
     (Container : Vector;
      Item      : Element_Type;
      Index     : Index_Type := Index_Type'First) return Extended_Index;

   function Find
     (Container : Vector;
      Item      : Element_Type;
      Position  : Cursor := No_Element) return Cursor;

   function Reverse_Find_Index
     (Container : Vector;
      Item      : Element_Type;
      Index     : Index_Type := Index_Type'Last) return Extended_Index;

   function Reverse_Find
     (Container : Vector;
      Item      : Element_Type;
      Position  : Cursor := No_Element) return Cursor;

   function Contains
     (Container : Vector;
      Item      : Element_Type) return Boolean;

   procedure Iterate
     (Container : Vector;
      Process   : not null access procedure (Position : Cursor));

   procedure Reverse_Iterate
     (Container : Vector;
      Process   : not null access procedure (Position : Cursor));

   function Iterate (Container : Vector)
      return Vector_Iterator_Interfaces.Reversible_Iterator'Class;

   function Iterate (Container : Vector; Start : Cursor)
      return Vector_Iterator_Interfaces.Reversible_Iterator'Class;

   generic
      with function "<" (Left, Right : Element_Type) return Boolean is <>;
   package Generic_Sorting is

      function Is_Sorted (Container : Vector) return Boolean;

      procedure Sort (Container : in out Vector);

      procedure Merge (Target : in out Vector; Source : in out Vector);

   end Generic_Sorting;

private

   pragma Inline (Append);
   pragma Inline (First_Index);
   pragma Inline (Last_Index);
   pragma Inline (Element);
   pragma Inline (First_Element);
   pragma Inline (Last_Element);
   pragma Inline (Query_Element);
   pragma Inline (Update_Element);
   pragma Inline (Replace_Element);
   pragma Inline (Is_Empty);
   pragma Inline (Contains);
   pragma Inline (Next);
   pragma Inline (Previous);

   use Ada.Containers.Helpers;
   package Implementation is new Generic_Implementation;
   use Implementation;

   type Elements_Array is array (Index_Type range <>) of aliased Element_Type;
   function "=" (L, R : Elements_Array) return Boolean is abstract;

   type Elements_Type (Last : Extended_Index) is limited record
      EA : Elements_Array (Index_Type'First .. Last);
   end record;

   type Elements_Access is access all Elements_Type;

   use Ada.Finalization;
   use Ada.Streams;

   type Vector is new Controlled with record
      Elements : Elements_Access := null;
      Last     : Extended_Index := No_Index;
      TC       : aliased Tamper_Counts;
   end record;

   overriding procedure Adjust (Container : in out Vector);
   overriding procedure Finalize (Container : in out Vector);

   procedure Write
     (Stream    : not null access Root_Stream_Type'Class;
      Container : Vector);

   for Vector'Write use Write;

   procedure Read
     (Stream    : not null access Root_Stream_Type'Class;
      Container : out Vector);

   for Vector'Read use Read;

   type Vector_Access is access all Vector;
   for Vector_Access'Storage_Size use 0;

   type Cursor is record
      Container : Vector_Access;
      Index     : Index_Type := Index_Type'First;
   end record;

   procedure Read
     (Stream   : not null access Root_Stream_Type'Class;
      Position : out Cursor);

   for Cursor'Read use Read;

   procedure Write
     (Stream   : not null access Root_Stream_Type'Class;
      Position : Cursor);

   for Cursor'Write use Write;

   subtype Reference_Control_Type is Implementation.Reference_Control_Type;
   --  It is necessary to rename this here, so that the compiler can find it

   type Constant_Reference_Type
     (Element : not null access constant Element_Type) is
      record
         Control : Reference_Control_Type :=
           raise Program_Error with "uninitialized reference";
         --  The RM says, "The default initialization of an object of
         --  type Constant_Reference_Type or Reference_Type propagates
         --  Program_Error".
      end record;

   procedure Write
     (Stream : not null access Root_Stream_Type'Class;
      Item   : Constant_Reference_Type);

   for Constant_Reference_Type'Write use Write;

   procedure Read
     (Stream : not null access Root_Stream_Type'Class;
      Item   : out Constant_Reference_Type);

   for Constant_Reference_Type'Read use Read;

   type Reference_Type
     (Element : not null access Element_Type) is
      record
         Control : Reference_Control_Type :=
           raise Program_Error with "uninitialized reference";
         --  The RM says, "The default initialization of an object of
         --  type Constant_Reference_Type or Reference_Type propagates
         --  Program_Error".
      end record;

   procedure Write
     (Stream : not null access Root_Stream_Type'Class;
      Item   : Reference_Type);

   for Reference_Type'Write use Write;

   procedure Read
     (Stream : not null access Root_Stream_Type'Class;
      Item   : out Reference_Type);

   for Reference_Type'Read use Read;

   --  Three operations are used to optimize in the expansion of "for ... of"
   --  loops: the Next(Cursor) procedure in the visible part, and the following
   --  Pseudo_Reference and Get_Element_Access functions. See Exp_Ch5 for
   --  details.

   function Pseudo_Reference
     (Container : aliased Vector'Class) return Reference_Control_Type;
   pragma Inline (Pseudo_Reference);
   --  Creates an object of type Reference_Control_Type pointing to the
   --  container, and increments the Lock. Finalization of this object will
   --  decrement the Lock.

   type Element_Access is access all Element_Type;

   function Get_Element_Access
     (Position : Cursor) return not null Element_Access;
   --  Returns a pointer to the element designated by Position

   No_Element : constant Cursor := Cursor'(null, Index_Type'First);

   Empty_Vector : constant Vector := (Controlled with others => <>);

   type Iterator is new Limited_Controlled and
     Vector_Iterator_Interfaces.Reversible_Iterator with
   record
      Container : Vector_Access;
      Index     : Index_Type'Base;
   end record
     with Disable_Controlled => not T_Check;

   overriding procedure Finalize (Object : in out Iterator);

   overriding function First (Object : Iterator) return Cursor;
   overriding function Last  (Object : Iterator) return Cursor;

   overriding function Next
     (Object   : Iterator;
      Position : Cursor) return Cursor;

   overriding function Previous
     (Object   : Iterator;
      Position : Cursor) return Cursor;

end Vectors;
