Method#args has a home now at http://method-args.rubyforge.org/ I released a new version too. It can be installed directly from the command line % sudo gem install method_args There are several new methods for more refined sorcery: % irb -r rubygems >> require 'method_args' >> class X; def foo(hello, world = 2, *blah); end; end >> method = X.new.method :foo => #<Method: X#foo> >> method.required_args => [:hello] >> method.optional_args => [:world] >> method.splat_arg => :blah >> method.args => [:hello, :world, :blah] ry