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   Stupid Question (was RE: [xml-dev] XML doesn't deserve its "X".)

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3/5/2002 12:35:49 PM, Nicolas LEHUEN <nicolas.lehuen@ubicco.com> wrote:

>
>That's what I was suggesting. However, I don't see how this can be achieved
>without adding type information (AKA PSVI) to XML elements, and have a
>typing system that supports extensibility. Looks like we're reinventing OOP
>there, with XML as a data serialisation format.

This is in the spirit of "if we were doing this all over again ..." (or
"if we were furry little creatures eating dinosaur eggs and planning for
the post-asteroid world ...), not a troll:  
Why does XML carry around a label for every data value rather than 
getting it from an out-of-band "schema" (a la EDI or
ASN.1), but then use an out-of-band means to associate type information,
thus necessitating the PSVI?

In a programming language, we say

  class MyData {
	Int    foo;
	String bar;
	Date   baz; }
   
Serializing an instance to XML gives:
	<myData>
		<foo>0xffffffff</foo>
		<bar>Someday/bar>
		<baz>20371031</baz>
      </myData>

Why not just put the type information inline and
make XML more "self-describing" (please don't
shoot me ...) 
	<myData>
		<foo my:type="Int">0xffffffff</foo>
		<bar my:type="String">Someday/bar>
		<baz my:type="Date">20371031</baz>
      </myData>


or else just give it up and use
ASN.1 for both the out-of-band 
label and type information ?

I'm sure this is a religious war I missed, somehow ...
and like I said, it's a stupid question, please be
merciful.






 

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