From: Robert Klemme <bob.news@...>
Date: 2003-09-16T17:30:28+09:00
Subject: Re: performance and style advice requested


"Robert Feldt" <feldt@ce.chalmers.se> schrieb im Newsbeitrag
news:oprvj614c2oglyup@mail1.telia.com...
> Robert Klemme <bob.news@gmx.net> skrev den Tue, 16 Sep 2003 05:08:35
+0900:
>
> >> def fact(n)
> >> @facts[n] ||= (@facts.length..n).inject(@facts.last) {|f, i|
@facts[i] =
> > i * f}
> >> end
> >
> > And, I think there's a subtle bug with the inject parameter.  Another
> > version:
> >
> > def fact(n)
> > @facts ||= [0,1]
> > @facts[n] ||= (@facts.length..n).inject(@facts[-1]) {|f, i| @facts[i]
= i
> > * f}
> > end
> >
> Can you spell it out for me? I fail to see the difference.

Argh!  *My* fault!  I read "@facts.last" as "last index", but it's "last
element".  Oh just forget it...

/me scuffles away into some corner and coils up.

> And I wouldn't do the initial assignment inside the method when
> we're discussing performance...

Yeah.  I just put it there to ensure proper operation if someone copied
and pasted the code somewhere else.

Regards

    robert