Re: are there implementation reasons for not providing a break statement in an imperative language?

On Jan 13, 6:09 pm, noitalmost <noitalm...@cox.net> wrote:
> I've noticed that Wirth has continually rejected the idea of a break
> statement and I was wonder why. Is this purely philosophical, or are
> there code optimization reasons? Naive code for a break is trivial to
> implement.
>
> Is it easier to optimize loops with no break? That is, is the cost of
> having extra booleans to control the loop less than the cost of
> messing up the basic blocks with break?
> [It's a little easy to optimize single-exit loops, but my impression is
> that the motivation was more like salvation through suffering. -John]


A compromise would be to allow only one "middle exit" per loop, and
to have it clearly indicated in the syntax rather than looking like
any old statement.


do{
        resource= getResource(counter);
}
exitwhen (resource.isOk());
{
          releaseResource(resource);
          counter.increment();
}
[It's been done, but never caught on that I could see. -John]

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