[LUCENE-3330] revise Scorer visitor API

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0-ALPHA
• Lucene Fields: New, Patch Available
• Assignee: Robert Muir
• Reporter: Robert Muir
• Created: 20/Jul/11 20:33
• Updated: 10/May/13 10:43
• Resolved: 17/Aug/11 21:13

Description

Currently there is an (expert) API in scorer to allow you to take a scorer, and visit its children etc (e.g. booleanquery).

I think we should improve this, so its general to all queries.

The current issues are:

• the current api is hardcoded for booleanquery's Occurs, but we should support other types of children (e.g. disjunctionmax)
• it can be difficult to use the API, because of the amount of generics and the visitor callback API.
• the current API enforces a DFS traversal when you might prefer BFS instead.