Actually, I forgot that the new frange query parser can let you filter on the output of a function...
http://www.lucidimagination.com/blog/tag/frange/ : : Maybe I'm missing something, but function queries aren't involved in : : determining whether a document matches or not, only its score. How is a a : : custom function / value-source going to filter? : : it's not ... i didn't realize that was the context of the question, i was : just answering the specific question about how to create custom functions. -Hoss
