Originally this was part of the patch for per-field Similarity (
LUCENE-2236), but I pulled it
out here as its own issue as its really mostly unrelated. I also like it as a separate issue
to apply the deprecation to branch_3x to just make less surprises/migration hassles for 4.0 users.
Currently Scorer takes a confusing number of ctors, either a Similarity, or a Weight + Similarity.
Also, lots of scorers don't use the Similarity at all, and its not really needed in Scorer itself.
Additionally, the Weight argument is often null. The Weight makes sense to be here in Scorer,
its the parent that created the scorer, and used by Scorer itself to support
But I dont think all queries work with this feature correctly right now, because they pass null.
Finally the situation gets confusing if you start to consider delegators like ScoreCachingWrapperScorer,
which arent really delegating correctly so I'm unsure features like
LUCENE-2590 aren't working with this.
So I think we should remove the getSimilarity, if your scorer uses a Similarity its already coming
to you via your ctor from your Weight and you can manage this yourself.
Also, all scorers should pass the Weight (parent) that created them, and this should be Scorer's only ctor.
I fixed all core/contrib/solr Scorers (even the internal ones) to pass their parent Weight, just for consistency
of this visitor interface. The only one that passes null is Solr's ValueSourceScorer.
I set fix-for 3.1, not because i want to backport anything, only to mark the getSimilarity deprecated there.