From: Phrogz <phrogz@...>
Date: 2007-12-12T04:45:01+09:00
Subject: Re: opposite .nil?

On Dec 11, 11:56 am, Andrew Stone <stoneli...@gmail.com> wrote:
> Note:  parts of this message were removed by the gateway to make it a legal Usenet post.
>
> if not my_var.nil?
>
> Thanks Justin.  I should have been more clear with the usage.
>
> def should_this_be_done?
>   am_I_sure?  && my_object.var  && !my_object.var.nil?
> end
>
> I just think it would read better if the last test was my_object.var.exists?

1) No such opposite-of-nil? method exists. If you want it, add it.

class Object
  def exists?
    true
  end
end

class NilClass
  def exists?
    false
  end
end

# up to you if you want this for FalseClass, too


2) In the particular example above (which I realize is just an
example) you could write that as:

  def should_this_by_done?
    am_I_sure? unless !my_object || my_object.var.nil?
  end

But, of course, that just moves the negation.