From: Erik Hollensbe <erik@...>
Date: 2007-06-12T18:15:38+09:00
Subject: Re: Getting the last N bytes of a string:

On 2007-06-04 10:40:32 -0700, Ryan Davis <ryand-ruby@zenspider.com> said:

> 
> On Jun 1, 2007, at 23:14 , Brian Candler wrote:
> 
>> I think I'll stick with buf[-10,10] || buf. I was just wondering if  I'd
>> missed something obvious like buf.last(10), after staring at 'ri  String' too
>> long.
> 
> you could do that too:
> 
>  >> "blah blah blah".split(//).last(4).join
> => "blah"
> 
> or do what you were looking for:
> 
>  >> class String; def last(n=1); self[-n, n] || self; end; end
> => nil
>  >> "blah".last(10)
> => "blah"
>  >> "blah blah".last(4)
> => "blah"

"blah blah blah".to_a.last(4).join as well.

It seems like a lot of Array methods would be better served as 
equivalents from Enumerable. #last is one of these.

(It won't nearly be as fast as a pure Array implementation, but it 
would be extremely useful.)