RE: ANN: XML Schema 1.1 Tutorial

 
Thanks Noah!

Excellent suggestions. I've incorporated them (see slide 28 and slide 232):

http://www.xfront.com/xml-schema-1-1/xml-schema-1-1.ppt

/Roger




> -----Original Message-----
> From: noah_mendelsohn@us.ibm.com [mailto:noah_mendelsohn@us.ibm.com] 
> Sent: Friday, July 17, 2009 2:53 PM
> To: Costello, Roger L.
> Cc: xmlschema-dev@w3.org
> Subject: Re: ANN: XML Schema 1.1 Tutorial
> 
> Roger: overall, I think this is excellent.  A very impressive 
> piece of 
> work.  One disagreement and one suggestion:
> 
> * Disagreement: 
> 
> You suggest: 
> 
> "Due to the restrictions on what the XPath can reference, I 
> recommend all 
> assertions be placed on the document's root element. "
> 
> First of all, assertions go on types, not elements, but 
> that's not my main 
> concern as your intention is clear.  I just think this is not 
> in general 
> good advice, because it undermines the value of assertions on 
> types that 
> are usable across documents.  Let's say I have some type, 
> perhaps for a 
> measurement that was taken repeatedly.  An element of that 
> type might look 
> like:
> 
>         <width minMeasurement="3.02"  maxMeasurement="3.06" 
> meanMeasurement="3.04" />
> 
> or, in the same document:
> 
>         <height minMeasurement="4.3"  maxMeasurement="5.2" 
> meanMeasurement="4.8" />
> 
> Let's assume these elements are both of complexType measurementType.
> 
> Very possibly, I'd want to <assert> that minMeasurement <= 
> meanMeasurement 
> <= maxMeasurement.  Why would I want to do that at the 
> document level? 
> Presumably, measurements like this could be used in lots of 
> documents and 
> on lots of differently named elements.  For this case, the assertion 
> belongs on measurementType, I think.  The same might well be 
> true of an 
> address type, which could check that the first two digits of 
> a zip code 
> are consistent with the name of the state.  Indeed, there are 
> many, many 
> common examples in which you don't want to hoist assertions 
> to the root, 
> IMO.  Reuse of these things is important!
> 
> * Suggestion:  in your discussion of precisionDecimal, you 
> might indicate 
> that one of the reasons it has been added is that it embodies 
> XML support 
> for the recently adopted IEEE 754-2008 standard for floating point 
> decimal.  Java BigDecimal or similar type in other 
> programming languages 
> are examples of implementations of IEEE 754-2008, just as 
> Java double and 
> float are implementations if IEEE 754 floating point binary.  
>  The new XSD 
> precisionDecimal type supports the use case where you have 
> data in your 
> program that is represented using such a type, and want to 
> serialize it 
> and validate in in XML, while preserving the 754-2008 semantics (e.g. 
> precision matters).
> 
> Noah
> 
> 
> 
> --------------------------------------
> Noah Mendelsohn 
> IBM Corporation
> One Rogers Street
> Cambridge, MA 02142
> 1-617-693-4036
> --------------------------------------
> 
> 
> 
> 
> 
> 
> 
> 
> "Costello, Roger L." <costello@mitre.org>
> Sent by: xmlschema-dev-request@w3.org
> 07/17/2009 01:37 PM
>  
>         To:     "xmlschema-dev@w3.org" <xmlschema-dev@w3.org>
>         cc:     (bcc: Noah Mendelsohn/Cambridge/IBM)
>         Subject:        ANN: XML Schema 1.1 Tutorial
> 
> 
> 
> Hi Folks,
> 
> I created a tutorial on XML Schema 1.1:
> 
> http://www.xfront.com/xml-schema-1-1/xml-schema-1-1.ppt
> 
> 
> I am announcing it here before announcing it on xml-dev.
> 
> I am eager to get your feedback on:
> 
> 1. Are there any mistakes in it?
> 
> 2. Is it clear? Is it easy to understand?
> 
> 3. Have I missed any of the new functionality?
> 
> 
> I would like to especially thank Michael Kay and Michael 
> Sperberg-McQueen 
> for their patience in answering my endless questions.
> 
> /Roger
> 
> 
>

Received on Saturday, 18 July 2009 11:45:55 UTC