From: Robert Klemme <bob.news@...>
Date: 2004-03-05T01:14:42+09:00
Subject: Re: Ruby won, of course


"Piergiuliano Bossi" <p_bossi_AGAINST_SPAM@tiscali.it> schrieb im
Newsbeitrag news:c27fab$p4h$1@lacerta.tiscalinet.it...
> Robert Klemme wrote:
> >>>+ #inject is even more performant since you omit the intermediate
> >
> > array of
> >
> >>>results.
> >>
> >>Yes, even if the combine_results method performs all the check anyway,
> >>while inject appears to stop as soon as a false value is reached. Not
a
> >>big issue, in any case.
> >
> >
> > inject doesn't stop prematurely unless you include a break or return
> > (which you didn't):
>
> You are right, my fault. Fact is that having eliminated combine_results
> method I now combine values using '&&' (or 'and'), which in turn
> performs a short-circuit evaluation ==> if the failing test is in the
> first group combined through '&&' the second group will never be
evaluated.
>
> I start thinking that combine_results cannot be avoided...

I'm afraid you're a bit confused now. :-)  What do you want
combine_results for?  It does not make a difference, because you eval'ed t
before.  And even if you didn't, switching order is sufficient.  You did
(with the slight modification of pulling v=eval(t) out of the string):

def check(*tests)
      stack = caller.map {|m| m[/\w*(?=')/]}.compact.reverse.join " "
      tests.inject(true) {|ret, t| v=eval(t); puts "#{v ? 'pass' : 'FAIL'}
..... (#{stack}) #{t.strip}"; ret && v}
end

It doesn't matter whether "ret && v" short circuits or not, because you
did eval it already.  And even if you didn't you could do "eval(t) && ret"
which would always eval.

Regards

    robert