re-enable support for custom multi-word synonyms #457
Merged
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As discussed in #456, the work in #453 had the unexpected consequences of dropping support for multi-word custom synonyms.
My general guidance here is that multi-word synonyms are poorly supported by lucene/elasticsearch and so should be avoided where possible, great care should be taken to ensure they are compatible with the
match_phrase
queries used by Pelias.Where possible I'd recommend using 'aliases' ie.
doc.setNameAlias()
instead, this is a reliable method of achieving the same thing, although it's far less convenient because it's on a per-record basis.So.. having said all that.. this PR re-enables support for multi-word synonyms (in custom synonyms files only) in order to avoid breaking backwards compatibility.
In order to do this I had to move the custom multi-word synonyms outside the multiplexer, apparently multiplexers emit tokens one-by-one to each of their branches, preventing the ability to 'look-ahead' as required by any multi-term analysis within a branch.
resolves #456