>Also, a question for Peter, at which stage do you use lucene analyzers
>on the query? After it was parsed into the tree, or before we start
>processing the query string?
I do the analysis before creating the tree. I'm pretty sure Lucene
QueryParser does this, too.
Peter
On Wed, Sep 14, 2011 at 5:15 AM, Roman Chyla <roman.ch...@gmail.com> wrote:
> Hi Peter,
>
> Yes, with the tree it is pretty straightforward. I'd prefer to do it
> that way, but what is the purpose of the new qParser then? Is it just
> that the qParser was built with a different paradigms in mind where
> the parse tree was not in the equation? Anybody knows if there is any
> advantage?
>
> I looked bit more into the contrib
>
> org.apache.lucene.queryParser.standard.StandardQueryParser.java
> org.apache.lucene.queryParser.standard.QueryParserWrapper.java
>
> And some things there (like setting default fuzzy value) are in my
> case set directly in the grammar. So the query builder is still
> somehow involved in parsing (IMHO not good).
>
> But if someone knows some reasons to keep using the qParser, please
> let me know.
>
> Also, a question for Peter, at which stage do you use lucene analyzers
> on the query? After it was parsed into the tree, or before we start
> processing the query string?
>
> Thanks!
>
> Roman
>
>
>
>
>
> On Tue, Sep 13, 2011 at 10:14 PM, Peter Keegan <peterlkee...@gmail.com>
> wrote:
> > Roman,
> >
> > I'm not familiar with the contrib, but you can write your own Java code
> to
> > create Query objects from the tree produced by your lexer and parser
> > something like this:
> >
> > StandardLuceneGrammarLexer lexer = new ANTLRReaderStream(new
> > StringReader(queryString));
> > CommonTokenStream tokens = new CommonTokenStream(lexer);
> > StandardLuceneGrammarParser parser = new
> > StandardLuceneGrammarParser(tokens);
> > StandardLuceneGrammarParser.query_return ret = parser.mainQ();
> > CommonTree t = (CommonTree) ret.getTree();
> > parseTree(t);
> >
> > parseTree (Tree t) {
> >
> > // recursively parse the Tree, visit each node
> >
> > visit (node);
> >
> > }
> >
> > visit (Tree node) {
> >
> > switch (node.getType()) {
> > case (StandardLuceneGrammarParser.AND:
> > // Create BooleanQuery, push onto stack
> > ...
> > }
> > }
> >
> > I use the stack to build up the final Query from the queries produced in
> the
> > tree parsing.
> >
> > Hope this helps.
> > Peter
> >
> >
> > On Tue, Sep 13, 2011 at 3:16 PM, Jason Toy <jason...@gmail.com> wrote:
> >
> >> I'd love to see the progress on this.
> >>
> >> On Tue, Sep 13, 2011 at 10:34 AM, Roman Chyla <roman.ch...@gmail.com>
> >> wrote:
> >>
> >> > Hi,
> >> >
> >> > The standard lucene/solr parsing is nice but not really flexible. I
> >> > saw questions and discussion about ANTLR, but unfortunately never a
> >> > working grammar, so... maybe you find this useful:
> >> >
> >> >
> >>
> https://github.com/romanchyla/montysolr/tree/master/src/java/org/apache/lucene/queryParser/iqp/antlr
> >> >
> >> > In the grammar, the parsing is completely abstracted from the Lucene
> >> > objects, and the parser is not mixed with Java code. At first it
> >> > produces structures like this:
> >> >
> >> >
> >>
> https://svnweb.cern.ch/trac/rcarepo/raw-attachment/wiki/MontySolrQueryParser/index.html
> >> >
> >> > But now I have a problem. I don't know if I should use query parsing
> >> > framework in contrib.
> >> >
> >> > It seems that the qParser in contrib can use different parser
> >> > generators (the default JavaCC, but also ANTLR). But I am confused and
> >> > I don't understand this new queryParser from contrib. It is really
> >> > very confusing to me. Is there any benefit in trying to plug the ANTLR
> >> > tree into it? Because looking at the AST pictures, it seems that with
> >> > a relatively simple tree walker we could build the same queries as the
> >> > current standard lucene query parser. And it would be much simpler and
> >> > flexible. Does it bring something new? I have a feeling I miss
> >> > something...
> >> >
> >> > Many thanks for help,
> >> >
> >> > Roman
> >> >
> >>
> >>
> >>
> >> --
> >> - sent from my mobile
> >> 6176064373
> >>
> >
>
