RE: [xml-dev] I have implemented SAX based XPath Engine

["Michael Kay" <mike@saxonica.com>]

Looks like a nice piece of work (if it works)

 

A few questions:

 

(a) I note that you support multiple downward selections in a predicate, for example

/root/pub[book/name and book/author]//book

I would be interested to know whether you do this in a pure streaming way, or whether you build an in-memory tree for any element that has such a predicate. (Saxon's streamable subset of XPath currently doesn't allow multiple downward selections).

 

(b) You've got an example that does *[last()].  Do you allow *[last() - 1]? Is this done with a pure streaming approach?

 

And a couple of comments:

 

(c) When you say "XPath", you seem to mean "XPath 1.0". It would avoid confusion to say that explicitly.

 

(d) I would think that a common way to use a SAX-based XPath engine is to filter the events, so that events are passed on to the next stage in the SAX pipeline only if they belong to nodes selected by the XPath expression. You don't seem to support this in your API.

 

Michael Kay

http://www.saxonica.com/

 

 

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From: Santhosh T [mailto:santhosh.tekuri@gmail.com]
Sent: 19 February 2009 01:07
To: xml-dev@lists.xml.org
Subject: [xml-dev] I have implemented SAX based XPath Engine

I have implemented a SAX based XPath Engine in java called XMLDog

Interested developers can have a look at:
   http://code.google.com/p/jlibs/wiki/XMLDog

It is part of project called JLibs:
   http://code.google.com/p/jlibs

Your comments are welcomed

- Santhosh