File : input_sources-file.ads


-----------------------------------------------------------------------

--                XML/Ada - An XML suite for Ada95                   --

--                                                                   --

--                       Copyright (C) 2001                          --

--                            ACT-Europe                             --

--                       Author: Emmanuel Briot                      --

--                                                                   --

-- This library is free software; you can redistribute it and/or     --

-- modify it under the terms of the GNU General Public               --

-- License as published by the Free Software Foundation; either      --

-- version 2 of the License, or (at your option) any later version.  --

--                                                                   --

-- This library is distributed in the hope that it will be useful,   --

-- but WITHOUT ANY WARRANTY; without even the implied warranty of    --

-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU --

-- General Public License for more details.                          --

--                                                                   --

-- You should have received a copy of the GNU General Public         --

-- License along with this library; if not, write to the             --

-- Free Software Foundation, Inc., 59 Temple Place - Suite 330,      --

-- Boston, MA 02111-1307, USA.                                       --

--                                                                   --

-- As a special exception, if other files instantiate generics from  --

-- this unit, or you link this unit with other files to produce an   --

-- executable, this  unit  does not  by itself cause  the resulting  --

-- executable to be covered by the GNU General Public License. This  --

-- exception does not however invalidate any other reasons why the   --

-- executable file  might be covered by the  GNU Public License.     --

-----------------------------------------------------------------------


with Unicode;
with Unicode.CES;

package Input_Sources.File is

   type File_Input is new Input_Source with private;
   type File_Input_Access is access all File_Input'Class;
   --  A special implementation of a reader, that reads from a file.


   procedure Open (Filename : String; Input : out File_Input);
   --  Open a new file for reading.

   --  Note that the file is read completly at once, and saved in memory.

   --  This provides a much better access later on, however this might be a

   --  problem for very big files.

   --  The physical file on disk can be modified at any time afterwards, since

   --  it is no longer read.

   --  This function can decode a file if it is coded in Utf8, Utf16 or Utf32


   procedure Close (Input : in out File_Input);
   --  Close the file and free the memory


   procedure Next_Char
     (From : in out File_Input;
      C    : out Unicode.Unicode_Char);
   --  Return the next character in the file.


   function Eof (From : File_Input) return Boolean;
   --  True if From is past the last character in the file.


private
   type File_Input is new Input_Source with
      record
         Index  : Natural;
         Buffer : Unicode.CES.Byte_Sequence_Access;
      end record;
end Input_Sources.File;