Re: Error definition

I think *and* vice versa (at least under the hood), although that may be my own lack of knowledge and imagination!  I await confirmation from better minds than my own.

In any case, I don’t think it particularly effects the facts of the matter: if the output you expect is a vxml node, and your parser can’t produce one, I agree you should be given an error.

You may also want a recogniser mode or function that produces a boolean to answer the question “can this parse” - but that is out of scope of our work on the specification, so far.

_________________
Tomos Hillman
eXpertML Ltd
+44 7793 242058
On 4 Feb 2022, 12:30 PM +0000, Bethan Tovey-Walsh <accounts@bethan.wales>, wrote:
> > I think that any parser is necessarily also a "recogniser"
>
> Yes, but not vice versa (I think?). So that was my point - if what we have is *only* a recognizer, all it has to do is say yes or no, and either answer may be equally interesting. But if it’s a parser, it needs to parse. In the case of ixml, if it can’t recognize it can’t parse, so it fails.
>
> > I suppose there may also be errors that are due to reasons other than the input not being a sentence in the grammar: we really ought to think about having some standard error codes.
>
> One that springs to mind is a badly-formed grammar.
>
> BTW
> ___________________________________________________
> Dr. Bethan Tovey-Walsh
> Myfyrwraig PhD | PhD Student CorCenCC
> Prifysgol Abertawe | Swansea University
> Croeso i chi ysgrifennu ataf yn y Gymraeg.
>
> > On 4 Feb 2022, at 12:13, Tom Hillman <tom@expertml.com> wrote:
> >
> > I don't think you are wrong, although I think that any parser is necessarily also a "recogniser": to "recognise" a piece of text, all you can really do is try to parse it and see if it succeeds...
> >
> > I suppose there may also be errors that are due to reasons other than the input not being a sentence in the grammar: we really ought to think about having some standard error codes.
> >
> > _________________
> > Tomos Hillman
> > eXpertML Ltd
> > +44 7793 242058
> > On 4 Feb 2022, 12:00 +0000, Bethan Tovey-Walsh <accounts@bethan.wales>, wrote:
> > > I’m inclined to agree with Dave. I wouldn’t call it an error if the implementation were only a recogniser: it would make sense in that context for the outcomes “yes, this is a sentence” and “no, this is not a sentence” to be of (potentially) equal interest and value. But the point of the ixml parser is to provide vxml output, not to tell you whether your input string is a valid sentence or not. If it can’t provide that output, I’d call that an error.
> > >
> > > Happy to hear why I’m wrong, though; my instinctive understanding is sometimes way off base.
> > >
> > > Sent from my iPhone
> > >
> > > > On 4 Feb 2022, at 09:36, Dave Pawson <dave.pawson@gmail.com> wrote:
> > > >
> > > > O Regan, Gonorill, your old kind father
> > > > Whose franke heart gaue you all, O that way madnes lies,
> > > > Let me shun that, no more of that.
> > > > -Bill S
> > > >
> > > > When I compile a programming language program,
> > > > I may get warnings, but (to me) the compile either
> > > > succeeds or fails.
> > > >
> > > > I would hope that with an ixml grammar and input string
> > > > I can rely on the same reasoning? Pass / fail (or pass,
> > > > with warnings). From this I expect my vxml output to
> > > > be complete, no 'missing bits'?
> > > >
> > > > I'm using a Saxon class implementation, so if it has a bug
> > > > I can look for a blue moon.
> > > >
> > > > Is this assumption reasonable / agreed?
> > > >
> > > >
> > > >
> > > > regards
> > > >
> > > >
> > > >
> > > >
> > > > --
> > > > Dave Pawson
> > > > XSLT XSL-FO FAQ.
> > > > Docbook FAQ.
> > > >
> > >
> > >
>