From: Austin Ziegler <halostatue@...>
Date: 2004-09-26T11:52:06+09:00
Subject: Re: Proc / def / yield semantics (long)

Actually, Markus, your examples don't work in 1.8.2 at all -- neither
the tickl() method or the tickler proc. These do:

def tickle(head, *rest)
  head.giggle if head.respond_to? :giggle
  tickle(*rest) unless rest.empty?
end

tickler = Proc.new { |head, *rest|
  head.giggle if head.respond_to? :giggle
  tickler.call(*rest) unless rest.empty?
}

class Giggler
  def initialize(pos)
    @pos = pos
  end

  def giggle
    puts "#{@pos}: giggle"
  end
end

a = []
10.times do |pos|
  if (rand < 0.501)
    a << Giggler.new(pos)
  else
    a << Object.new
  end
end
p a

tickle(*a)
tickler[*a]

I don't claim to understand the difference, really -- with the
exception of the yield capability in Hash#each, I don't tend to rely
on auto-expansion, instead being explicit.

-austin