I've written a tokenizer/analyzer that parses a file extracting tokens and operate this analyzer/tokenizer on ASCII data consisting of XML files (the tokenizer skips over XML elements but maintains relative positioning). I've written many units tests to check the produced token stream and was confident that the tokenizer was working properly. Then I noticed two problems:<br>
<ol><li>StopFilter (using English stop words) does not properly filter the token stream output from my tokenizer. If I explicitly pass an array of stop words to the stop filter it still doesn't work. If I simply switch my tokenizer to a StandardTokenizer the stop words are appropriately filtered (of course the XML tags are treated differently). <br>
</li><li>When I try a simple search no results come up. I can see that my tokenizer is adding files to the index but a simple search (using Ferret::Index::Index.search_each) produces no results. <br></li></ol>I'm now trying to track down the above problem which seems to have led me to another (though possibly related) problem for which I am seeking an answer. Below is the token_stream() method of my analyzer (XMLAnalyzer). Note that I've commented out my custom tokenizer (XMLTokenizer) so that the StandardTokenizer is being used within my custom analyzer. <br>
def token_stream(field, str)<br> # ts = XMLTokenizer.new(str)<br> ts = StandardTokenizer.new(str)<br> # test_token_stream(ts)<br> ts<br> end<br>In the above I've commented out the test_token_stream() method taken from Balmain's Ferret book (O'Reilly, pg 68) that simply prints out the tokens contained within a stream; i.e.,: <br>
def test_token_stream(token_stream)<br> puts "\033[32mStart | End | PosInc | Text\033[m"<br> while tkn = token_stream.next<br> puts "%5d |%4d |%5d | %s" % [tkn.start, tkn.end, tkn.pos_inc, tkn.text]<br>
end<br> end<br><br>If I keep test_token_stream() commented out then the indexing and search work fine (using StandardTokenizer). However, if I do not comment out test_token_stream() then creating the index appears to work fine but a search produces no results. I haven't been able to track this down but thought it might be related to the problems I was having with XMLTokenizer. Note that I create my index with the Ferret::Index::Index<br>
<br> index = Index::Index.new(:analyzer => XMLAnalyzer.new(),<br> :path => options.indexLocation,<br> :create_if_missing => true)<br>
<br>and I perform searches using Ferret::Search::Searcher<br><br>Any thoughts would be appreciated. <br><br>Regards,<br>John<br>aka sd.codewarrior<br><br><br><br>