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https://issues.apache.org/jira/browse/LUCENE-8717?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16787785#comment-16787785
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Jim Ferenczi commented on LUCENE-8717:
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While I understand why we'd need the deleted attribute I am a bit reluctant to
add another attribute just to handle deletion in graphs correctly. We'd need to
change all consumer of TokenStreams (which you partially do in the patch) to
handle the new attribute and IMO it feels weird to introduce a deleted
attribute if we don't use all the time (for non-articulation points). I wonder
if we should try to resurrect https://issues.apache.org/jira/browse/LUCENE-5012
to make graph token stream a first class citizen of the analysis stream ? It
could be a nice project for Lucene 9
> Handle stop words that appear at articulation points
> ----------------------------------------------------
>
> Key: LUCENE-8717
> URL: https://issues.apache.org/jira/browse/LUCENE-8717
> Project: Lucene - Core
> Issue Type: Bug
> Reporter: Alan Woodward
> Assignee: Alan Woodward
> Priority: Major
> Attachments: LUCENE-8717.patch
>
>
> Our set of TokenFilters currently cannot handle the case where a multi-term
> synonym starts with a stopword. This means that given a synonym file
> containing the mapping "the walking dead => twd" and a standard english
> stopword filter, QueryBuilder will produce incorrect queries.
> The tricky part here is that our standard way of dealing with stopwords,
> which is to just remove them entirely from the token stream and use a larger
> position increment on subsequent tokens, doesn't work when the removed token
> also has a position length greater than 1. There are various tricks you can
> do to increment position length on the previous token, but this doesn't work
> if the stopword is the first token in the token stream, or if there are
> multiple stopwords in the side path.
> Instead, I'd like to propose adding a new TermDeletedAttribute, which we only
> use on tokens that should be removed from the stream but which hold necessary
> information about the structure of the token graph. These tokens can then be
> removed by GraphTokenStreamFiniteStrings at query time, and by
> FlattenGraphFilter at index time.
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