[LUCENE-3177] Decouple indexer from Document/Field impls

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 4.0-ALPHA
• Lucene Fields: New
• Assignee: Michael McCandless
• Reporter: Michael McCandless
• Created: 07/Jun/11 09:56
• Updated: 20/Nov/24 13:43
• Resolved: 20/Mar/12 15:10

Description

I think we should define minimal iterator interfaces,
IndexableDocument/Field, that indexer requires to index documents.

Indexer would consume only these bare minimum interfaces, not the
concrete Document/Field/FieldType classes from oal.document package.

Then, the Document/Field/FieldType hierarchy is one concrete impl of
these interfaces. Apps are free to make their own impls as well.
Maybe eventually we make another impl that enforces a global schema,
eg factored out of Solr's impl.

I think this frees design pressure on our Document/Field/FieldType
hierarchy, ie, these classes are free to become concrete
fully-featured "user-space" classes with all sorts of friendly sugar
APIs for adding/removing fields, getting/setting values, types, etc.,
but they don't need substantial extensibility/hierarchy. Ie, the
extensibility point shifts to IndexableDocument/Field interface.

I think this means we can collapse the three classes we now have for a
Field (Fieldable/AbstracField/Field) down to a single concrete class
(well, except for LUCENE-2308 where we want to break out dedicated
classes for different field types...).

Issue Links

• is depended upon by: LUCENE-2308 Separately specify a field's type