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Re: [BLD] PS specs amendments

From: Michael Kifer <kifer@cs.sunysb.edu>
Date: Wed, 24 Sep 2008 23:45:56 -0400
To: "Hassan Ait-Kaci" <hak@ilog.com>
Cc: <public-rif-wg@w3.org>
Message-ID: <20080924234556.022713f7@kiferserv>



On Wed, 24 Sep 2008 17:44:43 -0700
"Hassan Ait-Kaci" <hak@ilog.com> wrote:

> Michael Kifer wrote:
> 
> > On Wed, 24 Sep 2008 05:47:25 -0700
> > "Hassan Ait-Kaci" <hak@ilog.com> wrote:
> > 
> > > Hello,
> > >
> > > In the light of the recent discussions regarding parsing the
> > > RIF BLD into RIF XML, I would like to submit the following
> > > to this WG to decide.
> > >
> > > I propose to change the current RIF BLD EBNF to:
> > 
> > Hassan,
> > 
> > #1 and #4 clash with the assumptions underlying PS&DTB.
> 
> Michael,
> 
> In several mails preceding the one in which I listed these 4 points,
> I pointed out in some details some of the problems caused by not having
> them.
> 
> Re: #1, allowing IRI's to appear unquoted (note that the <...>
> notation poses no problem, while something it is something like:
> 
>    Prefix ( foo http:/bar.baz/fuz# )
> 
> does), for example, the ':' in the IRI is not the ':' of a CURIE. How
> does a tokenizer know that ? All I am proposing is to change the
> notation to:
> 
>    Prefix ( foo "http:/bar.baz/fuz#" )
> 
> so that the problem disappears.

Here we are arguing about the details, not substance. I just pointed out that
"..." don't look good here because "http:/bar.baz/fuz#" is supposed to be
an xsd:string according to the DTB syntax. This is why I mentioned <...>
as a better alternative. (Also, see below before rushing to respond to that
one.)

> Re: #4, in a recent email, I pointed out to Harold that the current
> EBNF rules are inconsistent as they stand with his using CURIE's as
> argument names (see
> http://lists.w3.org/Archives/Public/public-rif-wg/2008Sep/0146.html).
> 
> So, unless I am missing something that you will explain to me, it is
> not that "#4 clash with the assumptions underlying PS&DTB" but rather
> that the assumptions underlying PS&DTB EBNF's are inconsistent!

Nope. The example is simply wrong (the book(cpt:author->?Author
cpt:title->bks:LeRif) part).

> > #3 is already in DTB, and I do not quite understand what you mean by #2.
> 
> #3 is indeed in the current spec, but not for named arguments Name's
> that do not derive CURIE's although all the examples Harod uses employ
> CURIE's for names of arguments.  Again, this is referring to recently
> exchanged email on the RIF list (e.g.,
> http://lists.w3.org/Archives/Public/public-rif-wg/2008Sep/0154.html).

Yes, and this is a mistake. (See the end of the msg about the possible ways
out.)

> Perhaps I have missed something that will explain to me.  Please go ahead.

as above.

> > Re #1, double quotes are reserved for the abridged syntax for strings in
> > DTB. The abridged syntax for IRIs is <...>.
> 
> Look at the examples. BTW, it is not true that "the abridged syntax
> for IRIs is <...>." The notation <foo> stands for "foo"^^rif:iri.  The
> use of IRI's in the EBNF is only limited to Prefix and Base grammar
> productions. As they appear there in the PS, there is not quoting
> and it is explained to "Recall that an IRI has the form of an
> internationalized resource identifier as defined by [RFC-3987]."

Right. What IRI is in Prefix and Base is up to us. We made it into a sequence
of unicode chars that form an IRI, but it could well be and IRICONST. There are
no objective criteria to decide, so we chose one of them (recall that we were
barred from making PS into a concrete language, and we were forced to
include statements to that effect in various places).

The problem is that "..." is a ^^xsd:string. So, if we want delimiters then it
should be something else. For example, '...'. Or we could make it into an
IRICONST.

> Again, what am I missing? Please explain.
> 
> > I do not understand what you are trying to achieve with #4.
> 
> What about: make the BLD examples consistent with the specs?

As I said, the example was wrong.

> > As far as I can see, it is not easy to reconcile this with PS, and I do not
> > understand why do you need this particular change.
> 
> From what I can read and understand from the documents available today,
> I beg to differ. But I concede that I may not have understsood everything.
> Again, whatever I am missing, I would be happy to understand.

The EBNF is consistent with the normative English spec for PS.
The examples have a problem. The easiest way out is to fix the examples.
Alternatively, we could generalize the spec. But in that case the solution is
not what you have proposed but rather get rid of the simplifying assumption
that the argument names come from a separate set ArgNames and instead use
arbitrary constants there.

I don't know whether it is ok to do such a generalization after the last call,
and I am not sure that this generalization is a good one either.

> Thanks for explaining.

Thanks for spotting the mistakes in the examples :-)

michael

 
> >         --michael 
> 
> -hak
> 
> > 
> > > 1. allow IRI's only within double quotes;
> > >
> > > 2. do not perform expansion of relative IRI's;
> > >
> > > 3. allow CURIE's everywhere as specified in the EBNF today
> > >    as CONSTSHORT's;
> > >
> > > 4. allow Name's to derive CURIE's.
> > >
> > > With the above simple amendments, I am confident that I can
> > > specify a workable tokenizer and Jacc grammar for a new
> > > version of my BLD->XML tool.
> > >
> > > In order to speed things up a bit, it would be nice if the
> > > above issues could be settled soon, so that I can proceed
> > > with the new release.  I will be travelling starting
> > > tomorrow and will spend the whole month of October working
> > > in ILOG France.  I will not attend this F2F in NYC - not
> > > even remotely (in fact I will be in planes most of its
> > > duration). I will attend the F2F debrief planned for next
> > > Tuesday's telecon.  Only after then will I have time to
> > > start implementing the above amendments.
> > >
> > > Have a fun F2F in NY, NY (my kinda town!)...
> > >
> > > Cheers,
> > >
> > > -hak
> > > --
> > > Hassan Aït-Kaci  *  ILOG, Inc. - Product Division R&D
> > > http://koala.ilog.fr/wiki/bin/view/Main/HassanAitKaci
> 
> 
> -hak
> --
> Hassan Aït-Kaci  *  ILOG, Inc. - Product Division R&D
> http://koala.ilog.fr/wiki/bin/view/Main/HassanAitKaci
> 
Received on Thursday, 25 September 2008 03:46:35 GMT

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