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Re: Subtyping in XML

• To: Jeff Lowery <jlowery@s...>
• Subject: Re: Subtyping in XML
• From: ht@c... (Henry S. Thompson)
• Date: 04 Sep 2002 22:49:57 +0100
• Cc: xml-dev@l...
• In-reply-to: <D60D8F448216D611A21A00508B62B5BC5D23@e...>
• References: <D60D8F448216D611A21A00508B62B5BC5D23@e...>
• User-agent: Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.2(beta13) (Demeter)

Jeff Lowery <jlowery@s...> writes:

> > > 1) Adding new value members to the value space of a type 
> > can't be any good
> > > under any circumstances.  It's possible to think up some 
> > use for such a
> > > feature, but it would no doubt be better implemented using 
> > one of the other
> > > mechanisms.
> > 
> > If you mean simple type == datatype, then not only is it bad, 
> > it's not 
> > possible using W3C XML Schema.  There is no derivation by extension
> > from simple types.
> 
> I think that's the intent, anyway.  I may be misremembering, but I thought
> there was a loophole or ambiguity in the spec that might allow one to add
> new enumeration values through simple type restriction?  In any case it's
> bad, bad,bad.

No loophole, nope.  At least, I sure hope not -- anyone?

ht
-- 
  Henry S. Thompson, HCRC Language Technology Group, University of Edinburgh
          W3C Fellow 1999--2002, part-time member of W3C Team
     2 Buccleuch Place, Edinburgh EH8 9LW, SCOTLAND -- (44) 131 650-4440
	    Fax: (44) 131 650-4587, e-mail: ht@c...
		     URL: http://www.ltg.ed.ac.uk/~ht/
 [mail really from me _always_ has this .sig -- mail without it is forged spam]

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  • RE: Subtyping in XML
    • From: Jeff Lowery <jlowery@s...>

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