Filter VilniusJS attendees emails

gistfile1.rb

lines = File.readlines('vilniusjs_emails')

result = []
remove = false

lines.each do |line|
  if line.strip.empty?
    remove = true
  end

  emails = line.split(',')
               .map(&:strip)

  if remove
    result -= emails
  else
    result += emails
  end
end

puts result.compact
           .uniq
           .sort
           .join(', ')