From: timsuth@... (Tim Sutherland)
Date: 2004-11-13T07:53:26+09:00
Subject: Re: non-nil, etc.  (was Re: true? & false?)

In article <4193F1FB.1060509@hypermetrics.com>, Hal Fulton wrote:
[...]
>You put a smiley, but in all seriousness I've thought of this.
>(Actually I'd use nonnil? or nnil?)
>
>In fact, when I'm writing code that no one else will see,
><admission type="shameful"/> I sometime use methods like these:
>
>   a1 = []
>   a2 = [1,2,3]
>   s1 = ""
>   s2 = "a string"
>   h1 = {}
>   h2 = {1=>2, 2=>4}
>
>   a1.null?    # true
>   a1.nnull?   # false
>   a2.null?    # false
>   a2.nnull?   # true
>
>   s1.null?    # true
>   h1.null?    # true
>
>   # And so on...
>
>See below, and let the flamefest begin.
[...]

    nil.nil?	# true
    nil.nnil?	# false
    nil.nnnil?	# true
    nil.nnnnil?	# false

class Object
    def method_missing(name, *args)
      if name.to_s =~ /^n*nil\?$/
        name.to_s.size % 2 == 0 ? nil? : !nil?
      else
        super
      end
    end
end