gcc/ada/libgnat/a-ststbo.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT LIBRARY COMPONENTS                          --
   4 --                                                                          --
   5 --           A D A . S T R E A M S . S T O R A G E . B O U N D E D          --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --             Copyright (C) 2020-2024, Free Software Foundation, Inc.      --
  10 --                                                                          --
  11 -- This specification is derived from the Ada Reference Manual for use with --
  12 -- GNAT. The copyright notice above, and the license provisions that follow --
  13 -- apply solely to the  contents of the part following the private keyword. --
  14 --                                                                          --
  15 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  16 -- terms of the  GNU General Public License as published  by the Free Soft- --
  17 -- ware  Foundation;  either version 3,  or (at your option) any later ver- --
  18 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  19 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  20 -- or FITNESS FOR A PARTICULAR PURPOSE.                                     --
  21 --                                                                          --
  22 -- As a special exception under Section 7 of GPL version 3, you are granted --
  23 -- additional permissions described in the GCC Runtime Library Exception,   --
  24 -- version 3.1, as published by the Free Software Foundation.               --
  25 --                                                                          --
  26 -- You should have received a copy of the GNU General Public License and    --
  27 -- a copy of the GCC Runtime Library Exception along with this program;     --
  28 -- see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see    --
  29 -- <http://www.gnu.org/licenses/>.                                          --
  30 --                                                                          --
  31 ------------------------------------------------------------------------------
  32
  33 package Ada.Streams.Storage.Bounded with Pure is
  34
  35    type Stream_Type (Max_Elements : Stream_Element_Count) is
  36      new Storage_Stream_Type with private with
  37       Default_Initial_Condition => Element_Count (Stream_Type) = 0;
  38
  39    overriding procedure Read
  40      (Stream : in out Stream_Type; Item : out Stream_Element_Array;
  41       Last   :    out Stream_Element_Offset)
  42        with Post =>
  43          (declare
  44             Num_Read : constant Stream_Element_Count :=
  45               Stream_Element_Count'Min
  46                 (Element_Count (Stream)'Old, Item'Length);
  47           begin
  48             Last = Num_Read + Item'First - 1
  49               and
  50             Element_Count (Stream) =
  51               Element_Count (Stream)'Old - Num_Read);
  52
  53    overriding procedure Write
  54      (Stream : in out Stream_Type; Item : Stream_Element_Array) with
  55       Post => Element_Count (Stream) =
  56       Element_Count (Stream)'Old + Item'Length;
  57
  58    overriding function Element_Count
  59      (Stream : Stream_Type) return Stream_Element_Count with
  60       Post => Element_Count'Result <= Stream.Max_Elements;
  61
  62    overriding procedure Clear (Stream : in out Stream_Type) with
  63       Post => Element_Count (Stream) = 0;
  64
  65 private
  66
  67    type Stream_Type (Max_Elements : Stream_Element_Count) is
  68      new Storage_Stream_Type with record
  69       Count : Stream_Element_Count := 0;
  70       Elements : Stream_Element_Array (1 .. Max_Elements);
  71    end record;
  72
  73 end Ada.Streams.Storage.Bounded;