There is also the Surround Query Parser in contrib by the way...I would bet
that Paul will tell you that it does not have these issues. I can't wait to
see the replies on this one...I didn't realize that the QueryParser had
these problems and am a bit skeptical...unfortunately I am away from home
and cannot check it out.
On another note...http://famestalker.com/devwik/ will be done soon...I only
have not gotten around to finishing the final touches because there did not
appear to be a lot of initial interest (and what there was has waned
drastically) and I am not ready to use it myself yet. It does correctly
handle order of operations however, and as far as I know is the only parser
to handle arbitray nesting and mixing of boolean and proximity queries.
(perhaps surround does as well...I would be really interested to know, but I
assume that it handles only the base cases ie not "(car & basket) within 2
of (horse & carriage within 3 of car). Of course who really cares about such
queries, but hey ;)
You'll get better advice from others more experienced, but my bet is that
Paul's surround parser is top notch and correctly does what you want.
- Mark
On 10/12/06, Renaud Waldura <[EMAIL PROTECTED]> wrote:
I'm developing an application used by scientists -- people who have a
pretty
good idea of what logic is -- and they were shocked to find out that
neither
of these queries return the same results:
1- banana AND apple OR orange
2- banana AND (apple OR orange)
3- (banana AND apple) OR orange
I'd expect (1) to be either (2) or (3), but it turns out it's parsed as
"+banana apple orange". I was rather, uh, dismayed by this find, as it
doesn't seem to make sense.
I just spent half a day reading up on the various ways QueryParser is
broken, by going through the bugs and the mailing-list archives. And I'm
still unable to come to a conclusion. Here's where I'm at:
a- queries which mix boolean operators require strict parenthesizing
to
work right
b- "+" isn't shorthand for "AND"; using it with "AND"/"OR"/"NOT" and
the
default operator "" rarely does what you expect
c- the stock QueryParser doesn't work well in these cases
d- there's a new PrecedenceQueryParser at
http://svn.apache.org/repos/asf/lucene/java/trunk/contrib/miscellaneousthat
solves *some* of the issues but creates others
e- there is a non-Lucene effort to create a query parser with a
different syntax at http://famestalker.com/devwiki/
While we are also developing a query-building UI, users must be able to
enter text queries as well. What do other folks do? I mean, this is pretty
bad. I can hardly go back to my scientists and tell them Lucene is unable
to
handle 2 boolean operators, that they should parenthesize everything by
hand. I mean, that's just cheesy.
--Renaud
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