RE: saxon impressions

[Kay Michael <Michael.Kay@xxxxxxx>]

> If you have a 1000 page book and you want to look at the index
> (assuming this index is in the source file, not generated on 
> the fly by
> the stylesheet) Then in a side effect free language you can start
> processing the nodes for the index and just process earlier nodes if
> explicitly referenced. With a saxon stylesheet you would 
> presumably have
> to process the entire book to make sure that any state variable are
> correctly initialised before you start the index.

With XSL today, if the style sheet asks for the whole book to be processed,
you have to process it. If it doesn't, you don't.  Global variables don't
affect this.

If XSL is extended to allow a stylesheet to be called to process a node in
the source document other than the root (e.g., the table of contents), then
granted, updateable global variables could cause problems. Local updateable
variables might still be manageable.

Don't get me wrong, I like the elegance of functional programming even if
I'm unpractised in the art. Trouble is, we're catering for a user community
that takes VBScript as its yardstick, and I think a lot of the questions on
this list suggest that there's a mismatch between the design of the language
and the skill level of the intended users. 

I put updatable variables into SAXON one morning when I was feeling
frustrated, just to see what the reaction would be: if they turn out to be a
bad idea, we will all have learnt something.

Mike Kay


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