From: Bertram Scharpf <lists@...>
Date: 2009-10-31T01:40:22+09:00
Subject: Re: How do you get the tail end of a string?

Hi,

Am Samstag, 31. Okt 2009, 00:12:01 +0900 schrieb Marnen Laibow-Koser:
> Bertram Scharpf wrote:
> > Am Freitag, 30. Okt 2009, 13:25:05 +0900 schrieb Michael W. Ryder:
> >> string[-index, index].
> > 
> > That's really ugly. You shouldn't have to mention `index' twice.
> 
> And you don't.  string[-index..-1] does the trick.
> 
> > I would even support a language extension to solve this problem.
> 
> No need.

You seem to be quite sure what you need. Look at this:

  irb(main):001:0> def timer ; start = Time.now ; yield ; Time.now - start ; end
  => nil
  irb(main):002:0> index = 2
  => 2
  irb(main):003:0> timer do 100_000.times { "hello"[-index..-1] } end
  => 0.888826
  irb(main):004:0> timer do 100_000.times { "hello".tail index } end
  => 0.21357

Your calculation needs more than four times as much processor
time. Don't you need to save time?

Bertram


-- 
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de