[relaxng-user] repeated data

[David Tolpin]

> David Tolpin scripsit:
> 
> > element foo { "a"+ }
> > 
> > is an invalid pattern. However, trang accepts it and converts into
> > corresponding XML Syntax.
> 
> It is indeed invalid.  Trang is not guaranteed to catch errors in input, and
> when the output is xsd, it may generate erroneous output as well.
> It's a best-effort program.

Thank you, I realize it now that since grouping restrictions are specified for
the simple form,  and trang does not translate to the simple form. 

Interestingly, nXML does not check restrictions either, and successfully validates
against this grammar (that is, it allows sequences of a, but not other strings).

Why this restriction is imposed at all?

David Tolpin