Fetch filenames using filter and REGEX

dir.rb

# In the following example some simple default options are set.
class Dir
  @list_options = { hidden_files: /^\./, visible_files: /^[^\.]/, files: // }

  def self.list(path = '.', option = :visible_files)
    entries(path).grep(@list_options[option])
  end
end

# Examples
Dir.list('.', :hidden_files).each { |file| print "#{file} " }; puts
Dir.list('.', :visible_files).each { |file| print "#{file} " }; puts
Dir.list('.', :files).each { |file| print "#{file} " }; puts

# OUTPUT
$> ruby dir.rb
. .. .DS_Store 
dir.rb test.json 
. .. .DS_Store dir.rb test.json 
$>