module SimpleConfiguration

# File lib/simple_configuration.rb, line 7
def config(config_name, default_value = MISSING_VALUE, &default_value_blk)

  if default_value_blk
    define_method(config_name) { |*args| instance_exec(*args, &default_value_blk) }
  elsif default_value != MISSING_VALUE
    define_method(config_name) { |*_| default_value }
  else
    define_method(config_name) { |*_| raise(MissingConfigurationError, config_name) }
  end

  define_singleton_method(config_name) do |value = nil, &blk|
    define_method(config_name) do |*args|
      blk ? instance_exec(*args, &blk) : value
    end
  end
end