[LUCENE-3041] Support Query Visting / Walking

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 4.0-ALPHA
• Fix Version/s: 8.1
• Component/s: core/search
• Lucene Fields: New, Patch Available
• Assignee: Alan Woodward
• Reporter: Chris Male
• Created: 22/Apr/11 14:11
• Updated: 28/Aug/22 12:44
• Resolved: 15/Mar/19 08:33

Description

Out of the discussion in LUCENE-2868, it could be useful to add a generic Query Visitor / Walker that could be used for more advanced rewriting, optimizations or anything that requires state to be stored as each Query is visited.

We could keep the interface very simple:

public interface QueryVisitor {
  Query visit(Query query);
}

and then use a reflection based visitor like Earwin suggested, which would allow implementators to provide visit methods for just Querys that they are interested in.

Issue Links

• relates to: LUCENE-3056 Support Query Rewriting Caching
• relates to: LUCENE-8184 Enable flexible Query.rewrite
• relates to: LUCENE-5718 More flexible compound queries (containing mtq) support in postings highlighter
• links to: GitHub Pull Request #581