[ https://issues.apache.org/jira/browse/LUCENE-1343?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12786941#action_12786941 ]
DM Smith commented on LUCENE-1343: ---------------------------------- I also am dubious about a general purpose folding filter that maps letters to their ASCII look-alike and agree that folding is language dependent. May Americans are illiterate when it comes to text with diacritics and NSM. Personally I'm nearly illiterate. I think having prominent folding filters without adequate explanation about their pitfalls or usefulness may lead illiterates into a false sense of sufficiency. If it makes sense to have a filter for TR39 I think that should be a separate issue. If that's what this issue is all about then it's description should be modified. I think this should otherwise be closed as a bad idea. Robert Muir, Would it make sense to have a Greek filter that strips diacritics? My thought is that if the letter is Greek then the diacritics would be removed, but otherwise it would not. Similar question for Hebrew, I see value in two filters: one would strip cantillation and the other, vowel points. Or would it be better to have one that can do both depending on flags? > A replacement for ISOLatin1AccentFilter that does a more thorough job of > removing diacritical marks or non-spacing modifiers. > ----------------------------------------------------------------------------------------------------------------------------- > > Key: LUCENE-1343 > URL: https://issues.apache.org/jira/browse/LUCENE-1343 > Project: Lucene - Java > Issue Type: Improvement > Components: Analysis > Reporter: Robert Haschart > Priority: Minor > Attachments: normalizer.jar, UnicodeCharUtil.java, > UnicodeNormalizationFilter.java, UnicodeNormalizationFilterFactory.java > > > The ISOLatin1AccentFilter takes Unicode characters that have diacritical > marks and replaces them with a version of that character with the diacritical > mark removed. For example é becomes e. However another equally valid way of > representing an accented character in Unicode is to have the unaccented > character followed by a non-spacing modifier character (like this: é ) > The ISOLatin1AccentFilter doesn't handle the accents in decomposed unicode > characters at all. Additionally there are some instances where a word will > contain what looks like an accented character, that is actually considered to > be a separate unaccented character such as Ł but which to make searching > easier you want to fold onto the latin1 lookalike version L . > The UnicodeNormalizationFilter can filter out accents and diacritical marks > whether they occur as composed characters or decomposed characters, it can > also handle cases where as described above characters that look like they > have diacritics (but don't) are to be folded onto the letter that they look > like ( Ł -> L ) -- 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: java-dev-unsubscr...@lucene.apache.org For additional commands, e-mail: java-dev-h...@lucene.apache.org