What ever is generating the xml could just as easily create/instantiate the 
query objects.
Yes, it is easier using the existing Java objects to construct queries but they are inappropriate when you consider the scenarios 1 to 3 I outlined earlier (query persistence, support for clients written in other languages or remote clients that don't want/need Lucene implementation classes locally). I find the separation of service request from service implementation is generally useful and using Query objects for both feels a bit dodgy.

I was not necessarily considering this proposal as a query language which power end-users would normally type. I saw this more as a syntax which would typically be generated by application code and could be conveniently persisted and/or serialized between machines. For example, I've a nice applet based GUI query builder for constructing boolean logic(see "Modern Information Retrieval" p285) which accumulates the user's query clauses, constructs a regular Lucene query string and sends it serverside. Unfortunately, using this approach I cannot offer the full range of Lucene query capabilities because they can't all be expressed in the existing query syntax. Yes,I could create Query objects in the client applet and serialize them to the server but how do I save them in an audit log or database of "saved queries"? I suspect there are many other Lucene applications which are essentially fronted by forms that are interpreted by application code to produce the query strings. In these scenarios where app code creates the query requests the "end-user-friendliness" of the query syntax may be a lesser priority compared to the required flexibility to represent all types of Lucene Queries - hence the XML suggestion, although I'm not married to that.

Yonik was right to highlight the parallel with  SQL here.




                
___________________________________________________________ To help you stay safe and secure online, we've developed the all new Yahoo! Security Centre. http://uk.security.yahoo.com

---------------------------------------------------------------------
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]

Reply via email to