Re: For loop over a collection, multiple

[Michael Kay]

> But you are right, interesting programs have side effects, 
> that is why we are running them. I just don't think the side 
> effects must or should be programmed in XQuery.

Yes: I have to say I'm inclined to push the model of using XProc as the
necklace that ties things together, and XQuery/XSLT for the processing
beads. The pipeline can be stateful while the individual steps are
stateless. I think using two languages with a shared data model actually
enforces a useful architectural separation that encourages modularity and
reusability of processing components which is hard to achieve if you write
everything in XQuery. It enables you to mix technologies very easily, and to
distribute the application across machines. It also fits in well with
XForms, which is a technology that deserves to be used far more than it is.

My last project had a step in the pipeline whose job was to fetch user
account information from a relational database. It makes sense to write that
in Java/SQL and integrate it at the pipeline level. Yes, you can do it via
an XQuery engine that will access a relational back-end, but that doesn't
mean you have to. You don't want to be limited to doing the things that your
chosen XQuery engine happens to support, and you don't want to start writing
XQuery code whose only role is to call methods written in Java.

Regards,

Michael Kay
http://www.saxonica.com/
http://twitter.com/michaelhkay