[Haskell-cafe] Parse stream using an external template for rules?

I'm not completely sure what I am looking for so I figured I'd ask the community. I have a project which reads data from a telnet stream (I wrote a pipes-network[1] library to handle this), however, rather than hard code the parsing rules with something like attoparsec (as I have done in my example) I'd like to define a template language which reads in a file with the template definitions that describes what to parse instead and use that inside the parser step. What tools and approaches would you recommend in this case? Or alternatively, a better solution? Thanks, Brian [1] https://github.com/alasconnect/pipes-telnet