How to store tree data in a Lucene/Solr/Elasticsearch index or a NoSQL db?

Question

Say instead of documents I have small trees that I need to store in a Lucene index. How do I go about doing that?

An example node in the tree:

class          


        

Answer 1

There is a project SIREn http://rdelbru.github.io/SIREn which deals with 'in-depth' trees, addressing. Internally uses Dewey numbering (http://www.ipl.org/div/farq/deweyFARQ.html) ....