# File lib/directory_watcher.rb, line 387
  def glob=( val )
    glob = case val
           when String; [File.join(@dir, val)]
           when Array; val.flatten.map! {|g| File.join(@dir, g)}
           else
             raise(ArgumentError,
                   'expecting a glob pattern or an array of glob patterns')
           end
    glob.uniq!
    @scanner.glob = glob
  end