lucenenet-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Digy (JIRA)" <j...@apache.org>
Subject [Lucene.Net] [jira] [Commented] (LUCENENET-414) The definition of CharArraySet is dangerously confusing and leads to bugs when used.
Date Fri, 13 May 2011 12:22:47 GMT

    [ https://issues.apache.org/jira/browse/LUCENENET-414?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13032982#comment-13032982
] 

Digy commented on LUCENENET-414:
--------------------------------

Hi Vincent,

I changed the CharArraySet implementation.
Can you take a look at 2.9.4g branch?

( https://svn.apache.org/repos/asf/incubator/lucene.net/branches/Lucene.Net_2_9_4g )

DIGY

> The definition of CharArraySet is dangerously confusing and leads to bugs when used.
> ------------------------------------------------------------------------------------
>
>                 Key: LUCENENET-414
>                 URL: https://issues.apache.org/jira/browse/LUCENENET-414
>             Project: Lucene.Net
>          Issue Type: Bug
>          Components: Lucene.Net Core
>    Affects Versions: Lucene.Net 2.9.2
>         Environment: Irrelevant
>            Reporter: Vincent Van Den Berghe
>            Priority: Minor
>             Fix For: Lucene.Net 2.9.2
>
>
> Right now, CharArraySet derives from System.Collections.Hashtable, but doesn't actually
use this base type for storing elements.
> However, the StandardAnalyzer.STOP_WORDS_SET is exposed as a System.Collections.Hashtable.
The trivial code to build your own stopword set using the StandardAnalyzer.STOP_WORDS_SET
and adding your own set of stopwords like this:
> CharArraySet myStopWords = new CharArraySet(StandardAnalyzer.STOP_WORDS_SET, ignoreCase:
false);
> foreach (string domainSpecificStopWord in DomainSpecificStopWords)
>     stopWords.Add(domainSpecificStopWord);
> ... will fail because the CharArraySet accepts an ICollection, which will be passed the
Hashtable instance of STOP_WORDS_SET: the resulting myStopWords will only contain the DomainSpecificStopWords,
and not those from STOP_WORDS_SET.
> One workaround would be to replace the first line with this:
> CharArraySet stopWords = new CharArraySet(StandardAnalyzer.STOP_WORDS_SET.Count + DomainSpecificStopWords.Length,
ignoreCase: false);
> foreach (string domainSpecificStopWord in (CharArraySet)StandardAnalyzer.STOP_WORDS_SET)
>     stopWords.Add(domainSpecificStopWord);
> ... but this makes use of the implementation detail (the STOP_WORDS_SET is really an
UnmodifiableCharArraySet which is itself a CharArraySet). It works because it forces the foreach()
to use the correct CharArraySet.GetEnumerator(), which is defined as a "new" method (this
has a bad code smell to it)
> At least 2 possibilities exist to solve this problem:
> - Make CharArraySet use the Hashtable instance and a custom comparator, instead of its
own implementation.
> - Make CharArraySet use HashSet<char[]>, defined in .NET 4.0.

--
This message is automatically generated by JIRA.
For more information on JIRA, see: http://www.atlassian.com/software/jira

Mime
View raw message