From: David Chelimsky <dchelimsky@...>
Date: 2006-10-06T20:28:48+09:00
Subject: Re: nil being empty

On 10/5/06, Ohad Lutzky <lutzky@gmail.com> wrote:
> Show of hands - who thinks this is bad form?
>
> class NilClass
>   def empty?; true; end
> end

Doesn't it depend on context? The other responders seem to suggest
that is objectively bad form, with which I  can agree (generally), but
in a case like this:

collection.select do |item|
  item.respond_to?(:empty?) and (!item.empty?)
end

I might prefer

collection.select do |item|
  true unless item.empty?
end

or this (which, though more terse, I personally find less readable)

collection.select do |item|
  !item.empty?
end

One of the beauties of the language (for me) is that language
invariants become somewhat less "in" and more "variant".