I?ve implemented a custom ranker in SQLite that is similar to SPH_RANK_SPH04 using FTS4 (BM25 + word distance and distance to beginning of text). The only thing that wasn?t possible out of the box using FTS4 was to get the distance between found matches as distance between them (how many words are between matches). FTS4 callback allows currently only to get this distance as byte offset, but not word distance.
As far as I remember, there are internal data structures in FTS4 which would allow this. But these structures aren?t available to the callback. Anyways, it will be nice if FTS5 would have a feature to get the distance between matched words expressed as word / token distance. Cheers Ben Am 14.09.15 16:13 schrieb "sqlite-users-bounces at mailinglists.sqlite.org on behalf of Abilio Marques" unter <sqlite-users-bounces at mailinglists.sqlite.org on behalf of abiliojr at gmail.com>: >SPH_RANK_SPH04
