Aminet 30/Aminet 30 (1999)(Schatztruhe)[!][Apr 1999].iso/Aminet/dev/lang/SmallEiffel.lha/SmallEiffel/lib_std/std_file_read.e

Text File | 1998-12-22 | 3KB | 171 lines

-- This file is  free  software, which  comes  along  with  SmallEiffel. This
-- software  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. You can modify it as you want, provided
-- this header is kept unaltered, and a notification of the changes is added.
-- You  are  allowed  to  redistribute  it and sell it, alone or as a part of
-- another product.
--          Copyright (C) 1994-98 LORIA - UHP - CRIN - INRIA - FRANCE
--            Dominique COLNET and Suzanne COLLIN - [e-mail]
--                       http://www.loria.fr/SmallEiffel
--
class STD_FILE_READ
--
-- Basic input facilities to read a named file on the disc.
--
-- Note : most features are common with STD_INPUT so you can
-- test your program on the screen first and then, just changing
-- of instance (STD_INPUT/STD_FILE_READ), doing the same in a file.
--

inherit INPUT_STREAM;

creation
   connect_to, make

feature

   path: STRING;
     -- Not Void when connected to the corresponding file
     -- on the disk.

feature {INPUT_STREAM}

   input_stream: POINTER;

feature {NONE}

   memory: INTEGER;
     -- Memory of the last available user's value.

feature

   make is
      do
      end;

   connect_to(new_path: STRING) is
      require
     not is_connected;
     not new_path.empty
      local
     p: POINTER;
      do
     p := new_path.to_external;
     input_stream := sfr_open(p);
     if input_stream.is_not_void then
        push_back_flag := false;
        memory := (' ').code;
        path := new_path;
     end;
      end;

feature

   disconnect is
      require
     is_connected
      do
     fclose(input_stream);
     path := Void;
      end;

   is_connected: BOOLEAN is
      do
     Result := path /= Void;
      end;

   read_character is
      do
     if push_back_flag then
        push_back_flag := false;
     else
        memory := read_byte(input_stream);
     end;
      end;

   last_character: CHARACTER is
      do
     Result := memory.to_character;
      end;

   unread_character is
      do
     push_back_flag := true;
      end;

   end_of_input: BOOLEAN is
      do
     if not push_back_flag then
        Result := memory = eof_code;
     end;
      end;

feature

   read_line_in(str: STRING) is
      local
     mem: INTEGER;
      do
     read_character;
     from
        mem := memory;
     until
        mem = eof_code
           or else
        mem = ('%N').code
           or else
        mem = ('%R').code
     loop
        str.extend(mem.to_character);
        mem := read_byte(input_stream);
     end;
     memory := mem;
     if mem = ('%R').code then
        read_character;
        if last_character /= '%N' then
           unread_character;
        end;
     end;
      end;

feature {FILE_TOOLS}

   same_as(other: like Current): BOOLEAN is
      require
     is_connected;
     other.is_connected
      local
     is1, is2: like input_stream;
     c1, c2: INTEGER;
      do
     from
        is1 := input_stream;
        is2 := other.input_stream;
     until
        c1 /= c2 or else c1 = eof_code
     loop
        c1 := read_byte(is1);
        c2 := read_byte(is2);
     end
     Result :=  c1 = c2;
     disconnect;
     other.disconnect;
      ensure
     not is_connected;
     not other.is_connected
      end;

feature {NONE}

   sfr_open(path_pointer: POINTER): POINTER is
      external "SmallEiffel"
      end;

   fclose(stream_pointer : POINTER) is
      external "C_InlineWithoutCurrent"
      end;

end -- STD_FILE_READ