From: x1 <caldridge@...>
Date: 2006-11-28T16:35:10+09:00
Subject: Re: find index of first non zeo value in array

Just saw this..

@ ruby conf, there were talks about the speed of ruby's regex

Being that ruby was the first language I picked up, I'm curious as to
how other languages(such as perl) compare from a performance
standpoint with your examples.

I'm not expecting perl to be slower an any scenerio, but is the perl
index() quicker or slower than a perl regex? If the latter, is the
performance ratio proportional to that of our ruby examples?



On 11/27/06, Tim Pease <tim.pease@gmail.com> wrote:
> On 11/27/06, William James <w_a_x_man@yahoo.com> wrote:
> >
> > William James wrote:
> > > Robert Klemme wrote:
> > > > On 26.11.2006 14:59, Josselin wrote:
> > > > > with :
> > > > > array = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 21, 0, 0, 0, 0, 0,
> > > > > 0, 0, 0, 0, 0]
> > > > >
> > > > > I wrote :
> > > > > array.index(array.detect {|x| x > 0})    => 15
> > > > >
> > > > > is there a better and simpler way to do it ?
> > > > > thanks
> > > >
> > > > Did we have a solution with #inject already?
> > >
> > > array.inject(0){|i,e| if e>0; break i else i+1 end}
> >
> > array.inject(0){|i,e| break i if e>0; i+1 }
> >
>
> Using a regular expression ...
>
> array.join =~ /[^0]/
>
> The inject method is faster, though, because you do not have to create
> a string. I'm assuming that the "array.index((array-[0])[0])" solution
> suffers from the same problem -- creating another object under the
> covers ...
>
> $ ruby tmp.rb
>                 user     system      total        real
> inject      2.874000   0.000000   2.874000 (  2.884000)
> index       0.721000   0.000000   0.721000 (  0.731000)
> regexp      3.755000   0.000000   3.755000 (  3.765000)
>
> Wow! Looks like the "index" method wins hands down.
>
> But mine is still shorter ;)
>
> TwP
>
>