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From: "Steve" <nospam_steved94@attbi.com>
Newsgroups: comp.lang.ada
References: <3E281B97.76F47E30@noSpam.raytheon.com>
Subject: Re: Keyword "null" Question
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Xref: archiver1.google.com comp.lang.ada:33165
Date: 2003-01-18T02:54:04+00:00
List-Id: <comp.lang.ada>

Is "SOME_EVENT_TOOK_PLACE" a function?  If so this is one way of discarding
the result.

If "SOME_EVENT_TOOK_PLACE" is a variable this may have been a trick to keep
the compiler from complaining about an unused variable or an optimizer
removing the variable altogether.

If you have the original development environment available you might just
try compiling with the code commented out.  The result may give you your
answer.

Steve
(The Duck)

"Michael Bustillo" <Michael_B_Bustillo@noSpam.raytheon.com> wrote in message
news:3E281B97.76F47E30@noSpam.raytheon.com...
> While reviewing the Ada LRM, it makes note that the Ada keyword "null"
> does nothing except pass to the next statement.  This seems intuitive
> enough, however...
>
> I'm currently attempting to reverse engineer some code so that it can be
> converted to another language, and I've run across the following:
>
>     if SOME_EVENT_TOOK_PLACE then
>         null;
>     end if;
>
> This statement is simply standing alone by itself, not part of any
> "case-like" structure or anything sneaky.  I guess my question is when
> it says "...it does nothing..." does it actually mean that it is putting
> a NO OP there?  Because then this would actually be doing something,
> most likely a timing issue, and that's what I need to know.
>
> I appreciate your time, and thanks.
>