"John Carter" <john.carter / tait.co.nz> schrieb im Newsbeitrag news:Pine.LNX.4.61.0408110946400.31851 / parore.tait.co.nz... > On Tue, 10 Aug 2004, Martin DeMello wrote: > > > Robert Klemme <bob.news / gmx.net> wrote: > >> > >> Hm, sounds to me like it was not general enough to include it in > >> Enumerable. Before I see that method I'd prefer to have size and empty? > >> in Enumerable. Just my 0.02 EUR... > > > > Can empty? be reliably implemented in terms of each for every > > enumerable? I can't think of an obvious problem with it, but that > > doesn't mean there isn't one. > > def empty? > each do |element| > return false > end > true > end > > def size > inject(0) {|n,e| n+=1} > end That's basically what i suggested earlier. Note though that you don't need the |element| in empty? as well as "n+1" is sufficient in size. But intermediately I changed my mind (see other thread). robert