lucene-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Adrien Grand (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (LUCENE-4955) NGramTokenFilter increments positions for each gram
Date Thu, 25 Apr 2013 08:30:16 GMT

    [ https://issues.apache.org/jira/browse/LUCENE-4955?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13641567#comment-13641567
] 

Adrien Grand commented on LUCENE-4955:
--------------------------------------

Given that offsets can't go backwards and that tokens in the same position must have the same
start offset, I think that the only way to get NGramTokenFilter out of TestRandomChains' exclusion
list (LUCENE-4641) is to fix position increments (this issue), change the order tokens are
emitted in (LUCENE-3920) and stop modifying offsets? I know some people rely on the current
behavior but I think it's more important to get this filter out of TestRandomChains' exclusions
since it causes highlighting bugs and makes the term vectors files unnecessary larger.
                
> NGramTokenFilter increments positions for each gram
> ---------------------------------------------------
>
>                 Key: LUCENE-4955
>                 URL: https://issues.apache.org/jira/browse/LUCENE-4955
>             Project: Lucene - Core
>          Issue Type: Bug
>          Components: modules/analysis
>    Affects Versions: 4.3
>            Reporter: Simon Willnauer
>             Fix For: 5.0, 4.4
>
>         Attachments: highlighter-test.patch, LUCENE-4955.patch
>
>
> NGramTokenFilter increments positions for each gram rather for the actual token which
can lead to rather funny problems especially with highlighting. if this filter should be used
for highlighting is a different story but today this seems to be a common practice in many
situations to highlight sub-term matches.
> I have a test for highlighting that uses ngram failing with a StringIOOB since tokens
are sorted by position which causes offsets to be mixed up due to ngram token filter.

--
This message is automatically generated by JIRA.
If you think it was sent incorrectly, please contact your JIRA administrators
For more information on JIRA, see: http://www.atlassian.com/software/jira

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


Mime
View raw message