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

RE: New presentation about XML Schema Datatypes

• To: "'John Cowan'" <jcowan@r...>,<xml-dev@l...>
• Subject: RE: New presentation about XML Schema Datatypes
• From: "Michael Kay" <michael.h.kay@n...>
• Date: Tue, 18 Jun 2002 09:56:28 +0100
• Importance: Normal
• In-reply-to: <200206172136.RAA29931@m...>
• Reply-to: <michael.h.kay@n...>

Some quibbles:

- you've classified decimal as "fixed point", but since Schema doesn't
say how arithmetic is performed, and since there are no facets for
precision and scale, there is no way of knowing whether the decimal type
was intended to be fixed point or floating point.

- you don't mention the important distinction between value space and
lexical space, and the notable fact that some facets constrain the value
space and others the lexical space.

- you don't mention the notion of canonical representation

- you steer well clear of thorny issues such as timezones

This is probably all that people need to know if they are using data
types solely for validation. If they are using them with processing in
mind, they probably need to know rather more: for example, they should
be aware that if they define a part number as an integer, then an
identity transformation is likely to remove any leading zeroes.

Michael Kay
Software AG
home: Michael.H.Kay@n...
work: Michael.Kay@s... 

> -----Original Message-----
> From: John Cowan [mailto:jcowan@r...] 
> Sent: 17 June 2002 22:37
> To: xml-dev@l...
> Subject:  New presentation about XML Schema Datatypes
> 
> 
> I have made available a brief presentation on XML Schema 
> Datatypes at http://www.ccil.org/~cowan/XML/dxspi.ppt
> This presentation is available under the GPL.  I would 
> appreciate any corrections to be posted here or emailed to me.
> 
> -- 
> John Cowan <jcowan@r...>     http://www.reutershealth.com
> I amar prestar aen, han mathon ne nen,    http://www.ccil.org/~cowan
> han mathon ne chae, a han noston ne 'wilith.  --Galadriel, _LOTR:FOTR_
> 
> -----------------------------------------------------------------
> 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>

• References:
  • New presentation about XML Schema Datatypes
    • From: John Cowan <jcowan@r...>

• Prev by Date: RE: Best Practice - beyond schema
• Next by Date: [ANN] Update of Topologi Schematron Validator adds RELAX NG
• Previous by thread: New presentation about XML Schema Datatypes
• Next by thread: Updated Unicode presentation from XML 2001
• Index(es):
  • Date
  • Thread