[oefrha]

> How else one is supposed to read environment variables from XSLT?

Setting aside whether it’s even a good idea to allow XSLT to do that, XPath is only a subset of XSLT, so you’re just changing the subject. The “path” in XPath should be a hint at what it’s supposed to be: a query language to select nodes by path in XML documents. As opposed to an alternative of Awk, or Perl.

[Mikhail_Edoshin]

I'd say XPath a way to get a nodeset or another XPath type out of something. E.g. the current date is not selected from a document. There always will be a need to get yet another thing as a nodeset, e.g. list a directory. Or, for boolean expressions, there will always be a need to test yet another thing, such as an environment variable.

These things, of course, should come as extension functions rather than special syntax, but then there will be a need to provide a small standard library of such functions :)

So yes, I believe it's useful if we're going to use XPath in a trusted environment, e.g. as a typical command-line tool. You won't deny Bash or Python this and other powerful abilities, will you? But of course it would be very unwise to run an untrusted Bash script.