class Sinatra::Base

def set(option, value=self, &block)
  raise ArgumentError if block && value != self
  value = block if block
  if value.kind_of?(Proc)
    metadef(option, &value)
    metadef("#{option}?") { !!__send__(option) }
    metadef("#{option}=") { |val| metadef(option, &Proc.new{val}) }
  elsif value == self && option.respond_to?(:each)
    option.each { |k,v| set(k, v) }
  elsif respond_to?("#{option}=")
    __send__ "#{option}=", value
  else
    set option, Proc.new{value}
  end
  self
end