config.rb

module Appdata
  $VERBOSE=nil
  # we don't want to instantiate this class - it's a singleton,
  # so just keep it as a self-extended module
  extend self

  # Appdata provides a basic single-method DSL with .parameter method
  # being used to define a set of available settings.
  # This method takes one or more symbols, with each one being
  # a name of the configuration option.
  def parameter(*names)
    names.each do |name|
      attr_accessor name

      # For each given symbol we generate accessor method that sets option's
      # value being called with an argument, or returns option's current value
      # when called without arguments
      define_method name do |*values|
        value = values.first
        value ? self.send("#{name}=", value) : instance_variable_get("@#{name}")
      end
    end
  end

  # And we define a wrapper for the configuration block, that we'll use to set up
  # our set of options
  def config(&block)
    instance_eval(&block)
  end

end