------------------------------------------------------------------------------
------------------------------------------------------------------------------
-- This file is part of 'Finite Field Arithmetic', aka 'FFA'.               --
--                                                                          --
-- (C) 2017 Stanislav Datskovskiy ( www.loper-os.org )                      --
-- http://wot.deedbot.org/17215D118B7239507FAFED98B98228A001ABFFC7.html     --
--                                                                          --
-- You do not have, nor can you ever acquire the right to use, copy or      --
-- distribute this software ; Should you use this software for any purpose, --
-- or copy and distribute it to anyone or in any manner, you are breaking   --
-- the laws of whatever soi-disant jurisdiction, and you promise to         --
-- continue doing so for the indefinite future. In any case, please         --
-- always : read and understand any software ; verify any PGP signatures    --
-- that you use - for any purpose.                                          --
--                                                                          --
-- See also http://trilema.com/2015/a-new-software-licensing-paradigm .     --
------------------------------------------------------------------------------
------------------------------------------------------------------------------

package body OS is
   
   -- Receive a character from the TTY, and True if success (False if EOF)
   function Read_Char(C : out Character) return Boolean is
      i : int;
      Result : Boolean := False;
   begin
      i := GetChar;
      if i /= EOF then
         C := Character'Val(i);
         Result := True;
      end if;
      return Result;
   end Read_Char;
   
   
   -- Send a character to the TTY.
   procedure Write_Char(C : in Character) is
      R : int;
      pragma Unreferenced(R);
   begin
      R := PutChar(int(Character'Pos(C)));
   end Write_Char;
   
   
   -- Send a Newline to the TTY.
   procedure Write_Newline is
   begin
      Write_Char(Character'Val(16#A#));
   end Write_Newline;
   
   
   -- Exit with an error condition report.
   procedure Eggog(M : String) is
   begin
      for i in 1 .. M'Length loop
         To_Stderr(M(I));
      end loop;
      
      -- Emit LF
      To_Stderr(Character'Val(16#A#));
      
      -- Exit
      Quit(Sadness_Code);
   end;
   
end OS;