Stefano Mazzocchi wrote:
>> o We do strongly believe that the XML pipeline language in OPS beats >> the ... out of Cocoon pipelines ;-) > > Oh, that's a bold statement :-)
Yes ;-)
> eheh, one step up and two step back. Your pipeline language feels > turing complete (haven't proved it but I think it's duable), if that > is what you mean by beating the ... out of, well, we have a > different definition of '...' :-)
Honestly, I wouldn't be able to tell you for sure if it is turing complete or not. XPL was not designed to be a general-purpose programming language, or anything even close. If you try to write a chess program in XPL, you will give up rapidly! In fact, XPL was designed to address a number of practical use cases directly related to processing XML documents / infosets. Yes there are conditionals and iterations, but it stops there.
> I do see value in more expressive power, but I also see a lot of > danger in introducing turing completeness in an XML > syntax. Everytime I see <if> or <foreach> I puke. XSLT made that > mistake first and now everybody is trying to make the same mistake.
Not sure why this is a mistake. As far as using an XML-based syntax, I am still of the school that it is a good thing: you can more easily automatically generate programs, even dynamically; creating software that creates a graphical representation of the program is easier; etc. You can also develop a non-XML compact syntax in addition to the XML syntax. This is what Relax NG has done.
-Erik
