Re: XPath support for using multiple ixml implementations

Hello,

Given what Norm says, the status quo might be adequate, at least if 'report
but not stop' is a mandate in the sense that I have to *be able* to see
ambiguities if I want. Alternative choices strike me as features, in that
context, because I can always look.

A formal ambiguity test also helps quite a bit. This means that developers
can at least know when they enter those waters.

Testability (as I also just said) is probably the key question in my mind.
:-)

Thanks again! Wendell


On Tue, Mar 3, 2026 at 10:47 AM Norm Tovey-Walsh <norm@saxonica.com> wrote:

> Wendell Piez <wapiez@wendellpiez.com> writes:
> > - A conformant processor must offer a mode to stop and report
> ambiguities instead of handling them
>
> I don’t like it. Supporting ambiguity is a defining feature of iXML that
> makes it easier to use than other grammars (and better to the extent that
> easier to use makes something better).
>
> > Maybe the mandated 'no ambiguities' mode would only have to report, not
> stop. But making it stop might be better.
>
> Report but don’t stop is the status quo. The output tells you if it is one
> of a set of ambiguous results.
>
> > If the spec is murkier, I would foresee a need for external tools to
> test for ambiguity. Is that formally possible?
>
> Yes. NineML ships with a formal ambiguity analyzer:
>
>   https://www.brics.dk/grammar/
>
> It will tell you where either of two flavors of ambiguity (horizontal or
> vertical) occur in your grammar.
>
>                                         Be seeing you,
>                                           norm
>
> --
> Norm Tovey-Walsh
> Saxonica
>


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