Taste Recommenders, LuceneIterable Weights and loading custom code

[Grant Ingersoll]

We are starting to get a couple of places where users can insert their  
own custom implementations.  Recommenders, Weight calculators (new  
today) and some other areas are all prime examples. Currently, it is  
likely the case that one has to do the whole un-jar/un-war dance in  
order to add their stuff in.

Solr had this problem and solved it through a custom class loader and  
the Solr Home capability.  Essentially, Solr defines a HOME which has  
a lib dir in it.  When someone wants to put their own custom code into  
Solr they merely have to jar up their code and drop it in the lib  
directory and then tell Solr about it.

Any thoughts on grabbing this functionality (SolrResourceLoader) and  
modifying it for Mahout for some of these things?  Not sure how it  
would play out for things running in Hadoop, but for both Taste and  
the utility functions it seems like a win.

-Grant