I'd imagine you could accomplish very similar results using SQLite and the full-text-search extension (FTS3, 4 or 5). I believe the SQLite FTS modules support a

I'd imagine you could accomplish very similar results using SQLite and the full-text-search extension (FTS3, 4 or 5). I believe the SQLite FTS modules support a porter-stemming tokenizer, though you may need to remove stop-words yourself. Before FTS5 you also need to write a user-defined function to rank results, but there are numerous libraries which provide good implementations (BM25, e.g.).