fn prefilter_with_literals(hir: &Hir) -> Option<(Prefilter, Vec<Literal>)>Expand description
Attempt to extract a prefilter from an HIR expression.
We do a little massaging here to do our best that the prefilter we get out of this is probably fast. Basically, the false positive rate has a much higher impact for things like the reverse inner optimization because more work needs to potentially be done for each candidate match.
Note that this assumes leftmost-first match semantics, so callers must not call this otherwise.