Boolean operators (Was: Re: New Alpha)

Tue, 15 Apr 1997 14:45:49 +0200

Berend de Boer wrote:

> >  * If statements and such now default to short-circuit operations.
> >    This can still be switched to complete evaluation using
> >    `--no-short-circuit', (*$B+*), or (*$no-short-circuit*).  With
> >    `--standard-pascal' etc., the default becomes complete evaluation
> >    and can be switched to short circuit using `--short-circuit',
> >    (*$B-*), or (*$short-circuit*).
> >
> >    (It is done this way because the cases where a program relies
> >on
> >    complete evaluation of Boolean expressions are very rare; functions
> >    with side effects should not occur in such situations anyway because
> >    you cannot rely on the order of evaluation.  OTOH, there are *many*
> >    programs which rely on short circuit evaluation.)
>
> I like to add that Extended Pascal has the or_else and and_then to force
> short circuit evalutation.
>
> A quite clean solution IMHO.

Indeed, I think this is good if one uses complete evaluation by default.
However, I prefer to have short circuit evaluation by default.
So what about similar operators to force complete evaluation - it would seem
cleaner to me than using {$B+} ... {$B-}?
-- 
Frank Heckenbach, Erlangen, Germany
heckenb@mi.uni-erlangen.de
Turbo Pascal:   http://www.mi.uni-erlangen.de/~heckenb/programs.htm
Internet links: http://www.mi.uni-erlangen.de/~heckenb/links.htm

Frank Heckenbach (heckenb@mi.uni-erlangen.de)