Re: Side-Effects in Functions [Rosen Trick]

[Brian Rogoff <bpr@bpr.best.vwh.net>]

On Thu, 22 Nov 2001, David Thompson wrote:
> Brian Rogoff <bpr@shell5.ba.best.com> wrote :
> > It's called void, not null. The problem with C is that it ignores returned
> > value types so even though it has void it doesn't really use it. I imagine
> > a reworked Ada would only allow void returning function/procedure values
> > to be ignores, and so wouldn't lose type safety.
> >
> I'm not sure what you were trying to say there.
[...snip...]
> What you may be after is that the value of any non-void expression
> in C, whether it is the return from a function or not, is discarded
> if that expression constitutes an entire statment.  

This is exactly what I was trying to say, thanks. In ML, an expression
oriented language, things separated by ";" must return unit (which is like
void) so you can't just ignore the results of functions unless you
explicitly request to do so. If we got rid of the function/procedure
distinction in an Ada like language then we'd do things this way I think.

-- Brian