[xquery-talk] XQuery static typing feature at risk

Michael Kay mike at saxonica.com
Wed Mar 11 22:36:54 PST 2009

> The XQuery Formal Semantics gives a very useful 'curly 
> braces' notation for scribbling XML Schema on whiteboards or 
> in text editors. I had been hoping the XSDL WG might even 
> have adopted it.

A concise syntax for XSD has been on the agenda for the WG, but the group is
very short of resources and decided to put this on the back burner. 

Of course one reason this syntax is nice is that it only covers the 10% of
XSD facilities that you use 90% of the time. If you try to define a concise
syntax that doesn't subset the functionality, it gets a lot more difficult.
Some of the things it leaves out are quite subtle - for example XSD allows
you define a sequence, choice, or all group containing a single particle,
whereas the FS concise syntax requires at least two particles. So you
immediately start a debate about whether the concise syntax needs to be
"complete": for some use cases it does, for others it doesn't.

Michael Kay

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