Single person hoby project to learn how a tripple store is implemented by developping one.
To become a RDF-tripplestore and SPARQL engine written in Common Lisp. I intend to store tripples indexed in various orders (e.g. subject/predicate/object, predicate/subject/object) in an adaptation of Prokopec's CTrie (see Cache-Aware Lock-Free Concurrent Hash Tries by Aleksandar Prokopec, Phill Bagwell, and Martin Ordersky): one that stores hierarchical keys, like a non-hashing CTrie, by the hash code of the parts, a nested hashing tries. This in a thread-save lock-free manner as the CTrie.
Currently working on kb-rdf/ctrie and kb-rdf/bitindexed-list. Some of the older attempts are messy; I will clean these.