Re: XSLT 2.0: function-available() for stylesheet functions

Hi Karsten,

> The reason why allowing user definitions to conflict with vendor
> definitions is a bad idea is that there is no guarantee whatsoever
> that the semantics is the same. Instead of grabbing the
> date:format-date() function from EXSLT, I could just as well
> implement something slightly (or outrageously) different under this
> name (in some well-hidden include), giving readers/users of my
> stylesheet a hard time understanding/debugging it.

But that won't change under your suggestion. You could still write a
user-defined function for date:format-date() with completely different
semantics and as long as you don't use it in a processor that natively
supports date:format-date() then you'll be just fine. Similarly,
there's nothing stopping me from writing an XSLT processor that works
completely differently from how XSLT is described in the
Recommendation. Or writing a different DTD for HTML and using that for
my web pages. Nothing can stop someone from ignoring standards if they
choose to.



Jeni Tennison

Received on Monday, 15 April 2002 17:38:10 UTC