ruby_closure.rb

class SMSGateway
  # @param phone [String]
  # @param message [String]
  def self.send_message(phone, message)
    puts "Hello #{phone}, #{message}"
  end
end

User = Struct.new(:phone, :active)

class MessageService
  # @param message [String]
  # @param recipients [Array<User>]
  def broadcast(message, recipients)
    recipients.each(&send_message(message))
  end

  private

  def send_message(message)
    ->(recipient) { SMSGateway.send_message(recipient.phone, message) if recipient.active}
  end
end

recipients = [
  User.new('+12345654547', true),
  User.new('+12345654548', false),
]
service = MessageService.new
service.broadcast('have a good day!', recipients)