Puppet, iterating over a hash

Today i fiddled about how to iterate over a hash in a puppet function (define). Okay, it is a bit .. scary but it works ;-)

define mymodule::myfunction($options = {}) {
     $cli_parameter = inline_template(
          "<% options.each_pair { |key, val| %> --<%= key %>=<%= val %><% } %>");
     // ...
}