Re: [xml-dev] Build applications using the "simplicity stack"

[Arjun Ray <arjun.ray@verizon.net>]

On Thu, 03 Apr 2014 22:46:22 +0100 (BST), Hans-Juergen Rennau
<hrennau@yahoo.de> wrote:

| Yes, XPath, this model of navigation, [...]

A minor quibble: Xpath is a method of addressing.  The mechanics are
secondary.

| [...] is like the heartbeat of XML technology [...]
| any XML technology is built on top of XPath. 

Indeed.  But as I alluded earlier, the possibilities may not have been
exhausted.

| But XPath is not the material from which to build systems: 

I don't think it was ever even intended to be.  It's just a DSL. 

| (a) it cannot construct (can only extract); 

The _syntax_ can be interpreted "constructively", as Miles Sabin and
Jeni Tennison demonstrated quite a while back on this list.  (Search
for the thread, "InnerXml is like printf")

 http://lists.xml.org/archives/xml-dev/200209/msg00720.html

| (b) it cannot create complexity.

That's for the tools that use it, of course.  

| The second detail that puzzled me was your phrase:
| "
| .. is good enough as long as it gets my data _out_ of XML.:-) 

For work with domain-specific business objects, as well as scripting
of batch jobs, where flat files still reign supreme.

| In my experience it is usually very easy to turn XML into something 
| else, but often rather laborious the other way around.

That's interesting because I often find the opposite, especially with
_badly designed_ XML: painful extraction and sloppy construction.  But
generating "good" XML isn't hard, either - and the mechanics can be
relatively trivial. 

Data should be stored in formats appropriate to purpose.  Systems are
built to satisfy business requirements, not to propitiate theories.