[LUCENE-8286] UnifiedHighlighter should support the new Weight.matches API for better match accuracy

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 7.5
• Component/s: modules/highlighter
• Lucene Fields: New
• Assignee: David Smiley
• Reporter: David Smiley
• Created: 01/May/18 17:22
• Updated: 28/Aug/22 15:29
• Resolved: 30/Aug/18 03:59

Description

The new Weight.matches() API should allow the UnifiedHighlighter to more accurately highlight some BooleanQuery patterns correctly – see LUCENE-7903.

In addition, this API should make the job of highlighting easier, reducing the LOC and related complexities, especially the UH's PhraseHelper. Note: reducing/removing PhraseHelper is not a near-term goal since Weight.matches is experimental and incomplete, and perhaps we'll discover some gaps in flexibility/functionality.

This issue should introduce a new UnifiedHighlighter.HighlightFlag enum option for this method of highlighting. Perhaps call it WEIGHT_MATCHES? Longer term it could go away and it'll be implied if you specify enum values for PHRASES & MULTI_TERM_QUERY?

Issue Links

• contains: LUCENE-7757 Unified highlighter does not highlight wildcard phrases correctly when ComplexPhraseQueryParser is used
• contains: LUCENE-7903 Highlighting boolean queries shouldn't always highlight some clauses
• is required by: SOLR-12754 Solr UnifiedHighlighter support flag WEIGHT_MATCHES
• is required by: LUCENE-9431 UnifiedHighlighter: Make WEIGHT_MATCHES the default
• links to: GitHub Pull Request #409