class Holidays::Finder::Rules::InRegion

def call(requested, available)
  return true if requested.include?(:any)
  # When an underscore is encountered, derive the parent regions
  # symbol and check for both.
  requested = requested.collect do |r|
    if r.to_s =~ /_/
      chunks = r.to_s.split('_')
      chunks.length.downto(1).map do |num|
        chunks[0..-num].join('_').to_sym
      end
    else
      r
    end
  end
  requested = requested.flatten.uniq
  available.any? { |avail| requested.include?(avail) }
end