[XML-DEV Mailing List Archive Home] [By Thread] [By Date] [Recent Entries] [Reply To This Message]

RE: Non-deterministic content model

• From: Murali Mani <mani@C...>
• To: Jason Chalecki <jchaleck@m...>
• Date: Wed, 13 Jun 2001 15:10:11 -0700 (PDT)

yes, i think kohsuke's original example is correct... please check..

cheers - murali.

On Wed, 13 Jun 2001, Jason Chalecki wrote:

> ((a, b)*, a) essentially represents the language where the first and
> last letter is a. Additionally, if there are b's, a and b must
> alternate. So (a, (b, a)*) matches the same language and is
> deterministic, correct?
>
> However, this is a specific solution and not a general algorithm to
> transform non-deterministic to deterministic.
>
> Jason
>
>
> -----Original Message-----
> From: Murali Mani [mailto:mani@C...]
> Sent: Wednesday, June 13, 2001 1:36 PM
> To: K.Kawaguchi
> Cc: Derek Denny-Brown; Steve Rosenberry; xml-dev@l...
> Subject: Re: Non-deterministic content model
>
>
> Actually Kohsuke is right -- (a & b?) is *not* inherently 1-ambiguous.
>
> Also I think, the language specified by ((a, b)*, a) cannot be written
> as
> an 1-unambiguous regular expression or 1-unambiguous model group -- I
> think --
>
> when you see an "a" in the string, you do *not* know whether it is the
> first a or the second a, unless you know whether there is b following
> it.
>
> i think the above example holds for all model groups defined to date --
> thanks a lot.
>
> are there any opinions/suggestions??
>
> Derek, try to give the content model for ((a, b)*, a), if you are not
> convinced.
>
> thanks and regards - murali.
>
> On Wed, 13 Jun 2001, K.Kawaguchi wrote:
>
> >
> > > (a, b? | b?, a)
> >
> > Since the above is the equivalent of ( a | ab | ba ),
> > you can write it as
> >
> > (a,b?) | (b,a)
> >
> > which is deterministic.
> >
> > How about this?
> >
> > > (a b)* a?
> >
> >
> > I think this cannot be written by the deterministic content model.
> >
> > regards,
> > ----------------------
> > K.Kawaguchi
> > E-Mail: kohsukekawaguchi@y...
> >
> >
> > ------------------------------------------------------------------
> > The xml-dev list is sponsored by XML.org, an initiative of OASIS
> > <http://www.oasis-open.org>
> >
> > The list archives are at http://lists.xml.org/archives/xml-dev/
> >
> > To unsubscribe from this elist send a message with the single word
> > "unsubscribe" in the body to: xml-dev-request@l...
> >
>
>
> ------------------------------------------------------------------
> The xml-dev list is sponsored by XML.org, an initiative of OASIS
> <http://www.oasis-open.org>
>
> The list archives are at http://lists.xml.org/archives/xml-dev/
>
> To unsubscribe from this elist send a message with the single word
> "unsubscribe" in the body to: xml-dev-request@l...
>

• References:
  • RE: Non-deterministic content model
    • From: Jason Chalecki <jchaleck@m...>

• Prev by Date: RE: Non-deterministic content model
• Next by Date: Re: Non-deterministic content model
• Previous by thread: RE: Non-deterministic content model
• Next by thread: Re: Non-deterministic content model
• Index(es):
  • Date
  • Thread