lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "DM Smith (JIRA)" <j...@apache.org>
Subject [jira] Commented: (LUCENE-2747) Deprecate/remove language-specific tokenizers in favor of StandardTokenizer
Date Wed, 10 Nov 2010 17:39:46 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-2747?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12930670#action_12930670
] 

DM Smith commented on LUCENE-2747:
----------------------------------

Robert/Steven, I'm sorry. I fat fingered the last post. I really need to take more care.
    s/Standard/Simple/;

That is, SimpleAnalyzer is not appropriate for many languages. If it were based upon a variation
of UAX29Tokenizer, but didn't handle NUM or ALPHANUM, but WORD instead, it would be the same
type of token stream, just alpha words.

Regarding compatibility: I think the results for English would be nearly, if not, identical.
Western European would only be slightly off from identical. But for other languages it would
be an improvement.

At this point, I'm content with what you guys are doing with non-English texts. Great job.


> Deprecate/remove language-specific tokenizers in favor of StandardTokenizer
> ---------------------------------------------------------------------------
>
>                 Key: LUCENE-2747
>                 URL: https://issues.apache.org/jira/browse/LUCENE-2747
>             Project: Lucene - Java
>          Issue Type: Improvement
>          Components: Analysis
>    Affects Versions: 3.1, 4.0
>            Reporter: Steven Rowe
>             Fix For: 3.1, 4.0
>
>         Attachments: LUCENE-2747.patch, LUCENE-2747.patch
>
>
> As of Lucene 3.1, StandardTokenizer implements UAX#29 word boundary rules to provide
language-neutral tokenization.  Lucene contains several language-specific tokenizers that
should be replaced by UAX#29-based StandardTokenizer (deprecated in 3.1 and removed in 4.0).
 The language-specific *analyzers*, by contrast, should remain, because they contain language-specific
post-tokenization filters.  The language-specific analyzers should switch to StandardTokenizer
in 3.1.
> Some usages of language-specific tokenizers will need additional work beyond just replacing
the tokenizer in the language-specific analyzer.  
> For example, PersianAnalyzer currently uses ArabicLetterTokenizer, and depends on the
fact that this tokenizer breaks tokens on the ZWNJ character (zero-width non-joiner; U+200C),
but in the UAX#29 word boundary rules, ZWNJ is not a word boundary.  Robert Muir has suggested
using a char filter converting ZWNJ to spaces prior to StandardTokenizer in the converted
PersianAnalyzer.

-- 
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.


---------------------------------------------------------------------
To unsubscribe, e-mail: dev-unsubscribe@lucene.apache.org
For additional commands, e-mail: dev-help@lucene.apache.org


Mime
View raw message