> Do you classify unambiguity of name classes as unambiguity of regular
> expressions?
I did not think about that while I was writing my mail. However, disambiguation
of name classes is not difficult.
> I am not sure I understand the difference between regular expressions
> and hedge grammars. Do you use them as two different levels?
Simply put, in a simplified RNG schema, regular expressions are second
children of <element>s, and represent sets of sequences of
<ref name="..."/>. Meanwhile, regular hedge grammars are
a bunch of <define>s having regular sets of <ref name=".."/> (i.e.,
we do not care which regular expression is used to represent such a regular set)..
> > We can combine these three kinds of unambiguity and introduce quite
> > a few variations of unambiguity! I would argue that different
> > tools require different variations of ambiguity. It does make
> > sense to allow ambiguous regular expressions but require
> > deterministic top-down hedge automata with one look-ahead.
>
> You mean that it would be a good compromise between flexibility and
> implementation and allow deterministic type assignment?
As for validation, I do not see any reasons to require determinism.
(By the way, restrictions on <interleave> is for another type of
determinism.) As for data binding tools, I think that different
data binding tools require different types of unambiguity
of regular expressions.
> BTW, I have a question about Relax NG... Wouldn't an "except" pattern
> have been useful out of the scope of datatypes?
Arguably, yes. But this has significant impacts on validation algorithms. I am
reluctant.
Cheers,
--
MURATA Makoto (FAMILY Given) <>
