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

RE: xPath 2.0, XSLT 2.0 ... size increase over v1.0

• To: "'Murali Mani'" <mani@C...>,<xml-dev@l...>
• Subject: RE: xPath 2.0, XSLT 2.0 ... size increase over v1.0
• From: "Michael Kay" <michael.h.kay@n...>
• Date: Wed, 11 Jun 2003 22:29:18 +0100
• Importance: Normal
• In-reply-to: <Pine.SOL.4.33.0306101128140.1801-100000@p...>
• Reply-to: <michael.h.kay@n...>

> Regarding mathematical properties: in particular, closure properties.
> 
> The operations being closed under regular tree languages 
> might be desirable property..

XSLT/XPath is closed with respect to its own data model. I don't know
how XSLT's data model relates to a "regular tree language", and I'm not
familiar with notations such as (a^n b^n).

Is there any chance you could translate this into XML terminology for
us?

The examples seem to suggest that your concerns are with queries that
generate a sequence of nodes rather than a single node. Sequences are
part of the data model, and the language is closed over this space.

Michael Kay
 
> 
> I have seen two kinds of operations under which regular tree 
> languages are not closed.. that is the result is not a 
> regular tree language..
> 
> (a) Consider the schema:
> S -> s (A, S, B) | s ()
> A -> a ()
> B -> b ()
> 
> if we write a query like // (a | b) -- the result is (a^n 
> b^n) which is not regular tree language..
> 
> (b) Consider
> S -> s (A*)
> A -> a ()
> 
> consider the query
> for $x in //a
>    return <b/>
> for $x in //a
>    return <c/>
> 
> the result is (b^n c^n)
> 
> The question is has the new constructs in XPath made it not 
> closed or not.. It might have.. If someone has studied these 
> aspects, then we can know if XPath 2.0 is different from 
> XPath 1.0 in these respects also..
> 
> cheers and regards - murali.
> 
> 
> -----------------------------------------------------------------
> The xml-dev list is sponsored by XML.org 
> <http://www.xml.org>, an initiative of OASIS 
<http://www.oasis-open.org>

The list archives are at http://lists.xml.org/archives/xml-dev/

To subscribe or unsubscribe from this list use the subscription
manager: <http://lists.xml.org/ob/adm.pl>

• Follow-Ups:
  • RE: xPath 2.0, XSLT 2.0 ... size increase over v1.0
    • From: Murali Mani <mani@C...>

• References:
  • Re: xPath 2.0, XSLT 2.0 ... size increase over v1.0
    • From: Murali Mani <mani@C...>

• Prev by Date: Re: xPath 2.0, XSLT 2.0 ... size increase over v1.0
• Next by Date: RE: xPath 2.0, XSLT 2.0 ... size increase over v1.0
• Previous by thread: Re: xPath 2.0, XSLT 2.0 ... size increase over v1.0
• Next by thread: RE: xPath 2.0, XSLT 2.0 ... size increase over v1.0
• Index(es):
  • Date
  • Thread