- From: Frank Olken <olken@lbl.gov>
- Date: Thu, 28 Sep 2000 17:40:17 -0700
- To: ddj@mclink.it
- CC: "'www-xml-schema-comments@w3.org'" <www-xml-schema-comments@w3.org>, carnold@houston.rr.com, mtbryan@sgml.u-net.com
Frank Olken wrote:
>
> Dear Dario de Judicibus:
>
> The XML Schema Working Group has spent the last several months
> working through the comments received from the public on the last-call
> draft of the XML Schema specification. We thank you for the comments
> you made on our specification during our last-call comment period, and
> want to make sure you know that all comments received during the
> last-call comment period have been recorded in our last-call issues
> list (http://www.w3.org/2000/05/12-xmlschema-lcissues).
>
> Among other issues, you raised the point registered as issue
> LC-61. simple-records: Allow record-style simple types?
>
> Please see the discussion below, and respond as to whether
> this resolution is satisfactory.
>
> LC-61. simple-records: Allow record-style simple types?
> -------------------------------------------------------
>
> Issue Class: D Locus: datatypes Cluster: 03 constructors Status:
> resolved
> Assigned to: Frank Olken Originator: Dario de Judicibus
>
> Description
> ------------
>
> Should the datatypes spec be modified to allow the construction of types
> with simple internal structure (e.g. to allow both quantity and units
> of measure to be captured in the same simple type)?
>
> Interactions and Input
> ----------------------
>
> Cf. Suggestion: Microparsing support in XML Schema
> Input from Dario de Judicibus:
> "Dario de Judicibus" <ddj@mclink.it> to XML Schema Comments list,
> Tue, 25 Apr 2000 23:12:02 +0200
>
> Final comment: there is no way to combine types. For example, if I have
>
> <xsd:simpleType name="units">
> <enumeration value="cm" />
> <enumeration value="in" />
> </xsd:simpleType>
>
> I have no way to define
> <height>12.4cm</height>
>
> by combining xsd:decimal and units. That might be very useful.
> We might use a variant of pattern for that:
>
> <xsd:complexType name="heightWithUnits">
> <xsd:pattern>
> <xsd:part type="xsd:decimal" />
> <xsd:part value="\p{Zs}*" />
> <xsd:part type="units" />
> </xsd:pattern>
> </xsd:complexType>
>
> Input from Curt Arnold:
> ----------------------
> Curt Arnold <carnold@houston.rr.com> to XML Schema Comments list,
> Wed, 26 Apr 2000 07:56:59 -0500
>
> The schema group stated that aggregate types were outside the
> scope of the initial version. Derivation by list was a hard fought
> exception to that principle.
> If you are interested in discussions of dimensional units in XML,
> I can send you URL's to quite a few discussions.
>
> Input from Martin Bryan <mtbryan@sgml.u-net.com>:
> -------------------------------------------------
> "Martin Bryan" <mtbryan@sgml.u-net.com> to XML Schema Comments list
> on Sun, 14 May 2000 08:01:08 +0100
>
> The one area I still expect we are going to have problems in
> using datatype for electronic commerce is measurements.
> For example, how can I check that 100cm and 1m are exactly equivalent,
> but 1yd is not. But again I do not expect you to have addressed
> these problems at this state.
> (Schema2 will be along within a few years!)
>
> Actual Resolution
> -----------------
>
> Discussed at Edinburgh Face to Face meeting.
> We think it would be unwise to introduce secondary notations
> for representing structures which can be represented
> satisfactorily using XML.
>
> Explanation (by F. Olken)
> -----------
>
> Various versions of this issue were the subject of
> considerable debate. The WG rejected the proposed changes
> on the grounds that the requirement could be reasonably met
> by use of some additional markup (in most cases), for example:
>
> <length>
> <value> 5.25 </value>
> <units> inches </units>
> </length>
>
> The working group recognizes that such constructions
> are not useable as single XML attributes.
>
> The WG was reluctant to go down the route of allowing further
> grammatical structure within elements/arguments, allow the WG
> felt obligated to preserve legacy composite structures such as
> IDREFS, etc.
>
> Essentially, the Working Group felt that the existing XML
> facilities could (largely) meet this requirement, and that
> further elaboration of the language was undesirable, especially
> in light of other comments we received that XML Schema Language
> was already too baroque.
>
> Another reason for this reluctance is that the measurement
> units application would eventually require more complex notations
> such as:
>
> <density> 5 kg/(meter^3) </density)
>
> which would require more elaborate grammars.
>
> The measurement units application is dear to my heart,
> and you are encourage to peruse the materials referenced
> from the web page:
>
> http://pueblo.lbl.gov/~olken/mendel/units/units.htm
>
> for a more extensive treatment of how to encode measurement
> units into XML.
>
> Is this response adequate ?
> ------------------------------
>
> We (XML Schema Working Group) want to know your opinion
> of our response to your last call comments. This information
> will be included with the package submitted to the W3C
> Executive Director as part of the recommendation to take
> the XML Schema Language to Candidate Recommendation.
> We would appreciate your response as soon as possible.
>
> Please choose from one of the following responses, adding
> whatever details, explanation you wish:
>
> 1) "Good enough" - You are satisfied with the Schema WG response
> to your comments on XML Schema Language. The response meets
> your requirements. The matter may be considered resolved.
>
> 2) "Stop the presses" - You are not happy with the response
> to your comments on XML Schema Language. Either the response
> is unclear or inadequate. The issue is of sufficient importance
> and urgency that you want it called to the attention of the
> W3C Executive Director and you ask that the XML Schema Language
> delayed in advancing to Candidate Recommendation until the
> issue is resolved.
>
> 3) "Later - Version 1.1" - You are not happy with the response,
> but are prepared to defer reconsideration until XML Schema Lang.
> Version 1.1 is drafted. It is anticipated (hoped) that Version 1.1
> will be completed by mid-2001. Version 1.1 is intended primarily
> to fix small issues needed by other W3C Working Groups to proceed
> with their work (especially XML Query Language). You request that
> your comments be reconsidered when drafting the Version 1.1
> requirements document.
>
> 4) "Later - Version 2.0" - You are not happy with the response,
> but are prepared to defer consideration until XML Schema Language
> Version 2.0 is drafted. It is anticipated that Version 2.0 would
> not be completed until late 2001 or early 2002. Version 2.0 may
> include major revisions, e.g., multiple inheritance, etc.
> You request that your comments be reconsidered when drafting the
> Version 2.0 requirements document.
>
> 5) "No longer care" - You are not happy with the response, but
> no longer care to pursue the matter, because ....
>
> Frank Olken
> XML Schema Language Working Group
>
> Lawrence Berkeley National Laboratory (510) 486-5891 (voice)
> Mailstop 50B-3238 (510) 486-4004 (fax)
> 1 Cyclotron Road (510) 843-5145 (home)
> Berkeley, CA 94720, USA (510) 442-7361 (pager)
>
> E-mail: olken@lbl.gov
> WWW: http://www.lbl.gov/~olken/
--
Frank Olken
Lawrence Berkeley National Laboratory (510) 486-5891 (voice)
Mailstop 50B-3238 (510) 486-4004 (fax)
1 Cyclotron Road (510) 843-5145 (home)
Berkeley, CA 94720, USA (510) 442-7361 (pager)
E-mail: olken@lbl.gov
WWW: http://www.lbl.gov/~olken/
Received on Thursday, 28 September 2000 20:40:21 UTC