VectorSimilarityFunction.getValues() does not implement doubleVal, throws UnsupportedOperationException

[hossman]

Description

VectorSimilarityFunction (and it's concrete subclasses) are the only ValueSource impls (AFAICT) that produce FunctionValues impls which do override floatVal(doc) but do NOT override doubleVal(doc) -- so they inherits the default impl from the FunctionValues abstract class, throwing UnsupportedOperationException

Practically speaking this means VectorSimilarityFunction subclasses are the only ValueSource impls (AFAICT) that can be used in a FunctionQuery, but can NOT be used in a FunctionScoreQuery because ValueSource.asDoubleValuesSource() delegates to the doubleVal(doc)

Version and environment details

Affects main, and all previous versions of Lucene that contain VectorSimilarityFunction

Fix (with tests) is fairly straight forward: lucene.bug.VectorSimilarityFunction.doubleVal.patch.txt

[dweiss]

Thanks, Hoss. There is a nocommit in this patch - is this intentional?

[hossman]

no, that's a stray comment left over from before i refactored the test ... ut wy didn't ./gradlew check complain about that on my system???

...

I guess the lucene build now requires some external tools to be installed?

hossman@slate:~/lucene/lucene [j25] [*main] $ git diff --staged | grep nocommit
+  // nocommit: duplicate this patterin in all tests
hossman@slate:~/lucene/lucene [j25] [*main] $ ./gradlew check -x test
The ast-grep tool location is not set ('lucene.tool.ast-grep' option), will not apply ast-grep rules.
The eclint tool location is not set ('lucene.tool.eclint' option), will not apply eclint checks.
The eclint tool location is not set ('lucene.tool.eclint' option), will not apply eclint checks.

> Task :errorProneSkipped
Errorprone linting turned off (skipped on builds not running inside CI environments, pass -Pvalidation.errorprone=true to enable)

[Incubating] Problems report is available at: file:///home/hossman/lucene/lucene/build/reports/problems/problems-report.html

BUILD SUCCESSFUL in 4s

[dweiss]

Yes. ast-grep is an external tool but it's not difficult to install (on linux or mac). It's much, much faster than the regexps we used to have... and most folks would probably run github actions (on a pull request) which includes all the checks.

[dweiss]

See here -
https://github.com/apache/lucene/blob/main/help/formatting.txt#L15-L43