From: Jano Svitok <jan.svitok@...>
Date: 2008-02-19T06:05:08+09:00
Subject: Re: The meanings of Asterisk (and Webby)

On Feb 18, 2008 9:46 PM, Leslie Viljoen <leslieviljoen@gmail.com> wrote:
> Hi all!
>
> I have a class that is used in a Webby page. The class needs to make
> use of a function within three modules:
>
> --------------------------------------------
> module Webby
> module Helpers #:nodoc:
> module UrlHelper
> --------------------------------------------
>
> Since the function is an "instance"
> function, I need to include the modules like so:
>
> --------------------------------------------
> class Categoriser
>         include Webby::Helpers::UrlHelper
> --------------------------------------------
>
> Later in my class I have (bear with me):
>
> --------------------------------------------
> def render
> ..
>   html << %[<li> #{link_to_page(:title => r.title)} </li>]
> --------------------------------------------
>
> link_to_page (within the three modules) looks like this:
>
> --------------------------------------------
>  def link_to_page( *args )
>     self.link_to(*_find_page(args))
>   end
> --------------------------------------------
>
> And gives me:
> NoMethodError Exception: undefined method `find' for nil:NilClass
>
> I can't find any reference to this usage of the asterisk, and
> I don't know what the *_find_page does. Can anyone explain it to me?

It's called the 'splat' operator.

see e.g.
http://theplana.wordpress.com/2007/03/03/ruby-idioms-the-splat-operator/
http://redhanded.hobix.com/bits/theSiphoningSplat.html
http://ola-bini.blogspot.com/2006/11/nooks-and-crannies-of-ruby.html