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https://issues.apache.org/jira/browse/LUCENE-1622?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12870619#action_12870619
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Michael McCandless commented on LUCENE-1622:
--------------------------------------------

bq. For other reasons, including this, we should start thinking about removing 
QueryParser's split-on-whitespace.

I think we should remove it!

The fact that QP does this whitespace pre-split means a SynFilter
(that applies to multiple words) is unusable with QP since the
analyzer sees only one word at a time from QP.

And, QP should be as language neutral as possible...


> Multi-word synonym filter (synonym expansion at indexing time).
> ---------------------------------------------------------------
>
>                 Key: LUCENE-1622
>                 URL: https://issues.apache.org/jira/browse/LUCENE-1622
>             Project: Lucene - Java
>          Issue Type: New Feature
>          Components: contrib/analyzers
>            Reporter: Dawid Weiss
>            Priority: Minor
>         Attachments: synonyms.patch
>
>
> It would be useful to have a filter that provides support for indexing-time 
> synonym expansion, especially for multi-word synonyms (with multi-word 
> matching for original tokens).
> The problem is not trivial, as observed on the mailing list. The problems I 
> was able to identify (mentioned in the unit tests as well):
> - if multi-word synonyms are indexed together with the original token stream 
> (at overlapping positions), then a query for a partial synonym sequence 
> (e.g., "big" in the synonym "big apple" for "new york city") causes the 
> document to match;
> - there are problems with highlighting the original document when synonym is 
> matched (see unit tests for an example),
> - if the synonym is of different length than the original sequence of tokens 
> to be matched, then phrase queries spanning the synonym and the original 
> sequence boundary won't be found. Example "big apple" synonym for "new york 
> city". A phrase query "big apple restaurants" won't match "new york city 
> restaurants".
> I am posting the patch that implements phrase synonyms as a token filter. 
> This is not necessarily intended for immediate inclusion, but may provide a 
> basis for many people to experiment and adjust to their own scenarios.

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