Details
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Improvement
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Status: Closed
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Minor
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Resolution: Fixed
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None
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None
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New
Description
I think we should add a matchVersion arg to StandardAnalyzer. This
allows us to fix bugs (for new users) while keeping precise back
compat (for users who upgrade).
We've discussed this on java-dev, but I'd like to now make it concrete
(patch attached). I think it actually works very well, and is a
simple tool to help us carry out our back-compat policy.
I coded up an example with StandardAnalyzer:
- The ctor now takes a required arg (Version matchVersion). You
pass Version.LUCENE_CURRENT to always get lates & greatest, or eg
Version.LUCENE_24 to match 2.4's bugs/settings/behavior.
- StandardAalyzer conditionalizes the "replace invalid acronym" and
"enable position increment in StopFilter" based on matchVersion.
- It also prevents creating zillions of ctors, over time, as we need
to change settings in the class. EG StandardAnalyzer now has 2
settings that are version dependent, and there's at least another
2 issues open on fixing some more of its bugs.
The migration is also very clean: we'd only add this to classes on an
"as needed" basis. On the first release that adds the arg, the
default remains back compatible with the prior release. Then, going
forward, we are free to fix issues on that class and conditionalize by
matchVersion.
The javadoc at the top of StandardAnalyzer clearly calls out what
version specific behavior is done:
* <p>You must specify the required {@link Version}
* compatibility when creating StandardAnalyzer:
* <ul>
* <li> As of 2.9, StopFilter preserves position
* increments by default
* <li> As of 2.9, Tokens incorrectly idenfied as acronyms
* are corrected (see <a href="https://issues.apache.org/jira/browse/LUCENE-1068">LUCENE-1608</a>
* </ul>
*