Re: Ada Protected Object Turorial #2: Overview of Tasks

[Robert A Duff <bobduff@world.std.com>]

Robert Dewar <robert_dewar@my-deja.com> writes:

> It would be like saying that since exceptions are a form of
> non-local gotos, that it makes sense to allow general non-local
> gotos :-)

Interesting.  You're obviously implying that the above argument is
patently absurd, but I'm not so sure it is!  ;-)

I used to use non-local gotos in Pascal once in a while, and I didn't
find them so horrible.  At least with a goto, you know where you're
going to.  Exceptions are less readable, in the sense that you might be
jumping to who-knows-where.  (Of course that's the whole *point* of
exceptions -- to separate the detection of an exceptional situation from
the determination of what to do about it.)

Of course non-local gotos in Ada would make no sense: I can't imagine
what it would mean to goto from a procedure into a different task, and
Ada doesn't provide any way to tell (at compile time) what tasks are
running what procedures.

- Bob