Article:		A Compact Syntax for W3C XML Schema
Subject:		Compact Syntax for W3C XML Schema
Date:		2003-08-27 21:18:44
From:		Robert Leif
A major purpose of software is that another human should be able to read and understand it. The author proposes to APLize XML schema. Invent a new write once, read maybe language. He evidently does not understand that one should avoid large schema and make multiple small schemas that correspond to classes or collections of classes. If one uses namespaces, one can locate the data types and elements contained in the small schemas. Cryptic software maximizes maintenance costs. One should be able to minimize comments; because the information is in the code. XML schema contains range checking, which is a type of assertion. Frankly, I so not want to see XML schema be replaced by another hacker language. Going back to DTD syntax is a huge mistake.

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• Compact Syntax for W3C XML Schema
  2003-08-29 13:36:21 Tom Gaven [Reply]
  
  Kudos to the WXCS team!!!

  
  I think Roberts distaste of a new "write once, read maybe language" is misguided. WXS is certainly a great example of a "write today, rewrite tomorrow because I'm never going to remember this syntax" kind of language.

  
  Of course, my favorite way to write WXS schemas will still be to use Trang and convert RNC to XSD. I think modelling WXS too closely is generally a bad idea:... 'ComplexTypes' 'SimpleTypes' 'AttributeGroups' ... etc... Who needs them??

  
  Long Live RELAXNG!!

  
  

  
  
  
  

• Compact Syntax for W3C XML Schema
  2003-08-28 04:55:05 Brian Ewins [Reply]
  
  You seem to have entirely missed the point.

  
  "A major purpose of software is that another human should be able to read and understand it."

  
  Do you really find WXS schema readable, let alone understandable? The syntax serves to obscure the purpose. The compact syntax of RNG and this one for WXS allow you to focus on the meaning.

  
  "Invent a new write once, read maybe language."

  
  Did you read the article? "[The author] implemented Java software that transforms WXSs between XML syntax and XSCS and vice versa.". If you can round trip XSCS, I can't see you being trapped by it.

  
  "He evidently does not understand that one should avoid large schema and make multiple small schemas..."

  
  If this was the case, why would the compact language support xsd:import and xsd:include? "Split up large files" and "use different syntax" are orthogonal issues.

  
  "XML schema contains range checking, which is a type of assertion."

  
  So does XSCS. Its another syntax for the same constraint model as WXS. What is your point?

  
  "Going back to DTD syntax is a huge mistake."

  
  Nothing in the article advocates that.

  
  I have not connection with the author but I felt compelled to write in support because your comment tried to defend wxs syntax on the grounds of *readablilty* - which is just ludicrous.
  
  

  • Compact Syntax for W3C XML Schema
    2003-09-16 11:14:26 Anthony Coates [Reply]
    
    Certainly I also don't find this compact syntax more readable than the XML. It is perhaps more *typeable* (yes, like APL) than the XML syntax, but that is only for vi and Notepad users. If your editor pops up the Schema tags, I don't see such a saving.

    
    Cheers, Tony.