I've dug up and down the ActiveRecord and FormHelper documentation and API, and I can't find how Rails goes from an AR class like `class Namespace::MyResource < ActiveRecord::Base` to the parameter name `namespace_my_resource`.

While I'm sure it's not hard to write my own method to do so `class ActiveRecord::Base; def to_pname; self.class.name.underscore.gsub(/\//, '_'); end; end`, this seems un DRY.