gnatstudio/examples/tutorial/common/sdc.adb

with Except;
with Screen_Output; use Screen_Output;
with Stack;
with Tokens; use Tokens;
with Ada.Text_IO; use Ada.Text_IO;
with Ada.Command_Line; use Ada.Command_Line;

procedure Sdc is
   File : File_Type;
begin
   Msg ("Welcome to sdc. Go ahead type your commands ...");

   if Argument_Count = 1 then
      begin
         Open (File, In_File, Argument (1));
      exception
         when Use_Error | Name_Error =>
            Error_Msg ("Could not open input file, exiting.");
            return;
      end;

      Set_Input (File);
   end if;

   loop
      --  Open a block to catch Stack Overflow and Underflow exceptions.

     begin

        Process (Next);
        --  Read the next Token from the input and process it.

     exception
        when Stack.Underflow =>
           Error_Msg ("Not enough values in the Stack.");

        when Stack.Overflow =>
          null;
     end;

   end loop;

exception
   when Except.Exit_SDC =>
      Msg ("Thank you for using sdc.");

   when others =>
      Msg ("*** Internal Error ***.");

end Sdc;