Re: Let's face it: side effects are sometimes necessar

Well, by transaction I meant, for instance, that the XSLT
would process an incoming order and would write that order
into a database. Or it would receive a cancellation of that
order and would delete that record from the order. By
transaction I meant more than fetching data. I meant changing
data. And a function performing a change of data once it
returns by definition has a side effect, right?

regards
-Gunther

Let me tickle a bit: you don't agree with the subject line, but
how do you suppose one could use XSLT to execute a transaction
in an information system? By definition this is using side-
effects. XML driven JDBC calls through XSLT is where I find the
best use of XSLT right now (I'm not a web-designer, but a
passionate XSLT user.)

- OK, I'll bite... why do transactions "by definition" require side
effects? I've written a prototype web server in XSLT with C#
extensions. These extensions only fetch the next web request, and send
back a response.

My "web server" operates in a completely stateless matter, simply by
taking XML from the request, applying templates, and piping the result
tree fragment over the wire.  It is therefore completely stateless and
side effect free, and still handles transactions just fine.

--
Gunther Schadow, M.D., Ph.D.                    gschadow@xxxxxxxxxxxxxxx
Medical Information Scientist      Regenstrief Institute for Health Care
Adjunct Assistant Professor        Indiana University School of Medicine
tel:1(317)630-7960                         http://aurora.regenstrief.org