Quoteing zen19725 / zen.co.uk, on Mon, Jun 21, 2004 at 05:33:17AM +0900:
> >> functionality). Unfortunately i can't find it (I was looking for
> >> something like a file called Enumerable.rb). Is it not there, or
> >> implemented in C or something?
> >Yup.  See enum.c
> 
> Is that for efficiency, or because it wouldn't be possible to 
> implement it in Ruby?

Efficiency, its one of the most commonly used modules in ruby.

Sam