I am not understanding user defined exceptions

[patrick@spellingbeewinnars.org]

Hi Everyone

I am not understanding user defined exceptions. This little program will ask the user for integer entry twice. If I type 1 at the first entry, things work as expected and the exception is handled.

However if I type, 2 and then 1, an exception is not raised at the second text_io.get.

If we type something like :    
         if x = 1
         then
           raise Foo_Error;
         end if ;
 
will x not be tested for exceptions conditions automatically from that point onward? If so, why would it not raise an exception if the second text_io.get came back with 1 ?

Sorry for what will very likely be a stupid question-Patrick






          with ada.integer_text_io ;
          with ada.text_io ;
       --
       --
       --
       --
       --
       --
        procedure test_exceptions is

        package text_io renames ada.text_io ;
        package int_text_io renames ada.integer_text_io ;

        Foo_Error : exception ;
        x : integer ;
        begin
           
         int_text_io.get(x) ;

         if x = 1
         then
           raise Foo_Error;
         end if ;
 

         int_text_io.get(x) ;

     -- why does execution reach this point if x is 1 after user input
         if x = 1
         then
            text_io.put_line("x is 1, why wasn't an exception triggered?") ;
         end if ;
 

        text_io.put_line("ended without exceptions") ;


        exception
           when Foo_Error =>
              text_io.put("error handled") ;
        end test_exceptions;