Hi Graham!
what are PMSG functions for, as part of the class import process?
The .pmsg was intended to be a general function for UGen's which allows one to pass string messages whose interpretations are solely defined by a particular UGen. For example, for a class such as Filter, it could take a formatted string via .pmsg to to set coefficients. The same pmsg string could mean something completely to another UGen. For the now, the .pmsg is not implemented to do anything interesting. It's just sitting there, probably waiting for strings operations to be implemented. As far as the import is concerned, a empty function returning TRUE is usually provided, though even this may not be necessary. I hope this help explain it. Best, Ge!