"Tobias Reif" <tobiasreif / pinkjuice.com> wrote in .... > how can I programmatically find out which objects a certain method can > take if any? If only ask for the arity assuming that klass is a Class object and meth a symbol or string. def k_arity(klass,meth) klass.class_eval { instance_method (meth).arity } end for singleton methods this would be def s_arity(obj,meth) class << obj; instance_method (meth).arity end end Qualified class names have to preprocessed with something like class String def to_constant(scope = ::Object) if md = (/(::)/).match(self) (md.post_match).to_constant(scope.const_get(md.pre_match)) else scope.const_get(self) end end end /Christoph