nano.rb

class Nanomachine
  class Nanoparticle
    def add(p)
      while more?
        p << self
    end
  end
end

# Ruby 1.9 includes nicer support for warnings that you didn't get in 1.8.
#
# [johnf@ubuntu-desktop][2010/02/27|18:08:17]
# [~/dev/talks/sandboxes/iruby]> iruby -W nano.rb
# iruby: warning: mismatched indentations: line 4:'while' and line 6:'end'
# iruby: warning: mismatched indentations: line 3:'def' and line 7:'end'
# iruby: warning: mismatched indentations: line 2:'class' and line 8:'end'
# nano.rb:8: syntax error, unexpected $end, expecting keyword_end