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Re: XML Schema: What does it *really* mean to declare an eleme

• From: Bjoern Hoehrmann <derhoermi@gmx.net>
• To: "Costello, Roger L." <costello@mitre.org>
• Date: Tue, 01 Jan 2013 22:28:06 +0100

* Costello, Roger L. wrote:
>I have an XML Schema in which I declared this element:
>
>        <xs:element name="W" type="xs:string" />
>
>What does that element declaration really mean?
>
>Does it mean that in an instance document I may only have this:
>
>    <W>...</W>
>
>Suppose I italicize the element name:
>
>    <W>...</W>

An XML document is essentially a sequence of characters, of Unicode
scalar values, of integers. So you have a first integer, and second,
and so on, and their only property of interest is the scalar value.

Seven is a prime number, right? What about a red seven in a blue box?
What about a straightened seven? When you picture a straightened "7"
you might think of a "1" and "1" is not typically regarded as a prime
number. But then again one might think that a straightened seven is
still a seven.

Deciding whether the straightened seven is a prime requires inter-
pretation which natural number "straightened seven" might correspond
to, and there is no single obviously correct interpretation.

The same goes for your question: We cannot tell which sequence of
characters you have in mind in your question, what the bits on the
wire are when you send your XML document somewhere, so the question
is incomplete. We could guess that in all cases the bits would be
the same, or we could guess that maybe Unicode has a character that
looks like an italicised 'W' and you would be using that in one but
not the other document. Perhaps whatever distinction you had in mind
got lost in transmission.

The typical reaction to a question like yours would be to ask you to
post links to the XML documents so no interpretation is necessary.
-- 
Björn Höhrmann · mailto:bjoern@hoehrmann.de · http://bjoern.hoehrmann.de
Am Badedeich 7 · Telefon: +49(0)160/4415681 · http://www.bjoernsworld.de
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• References:
  • XML Schema: What does it *really* mean to declare an element?
    • From: "Costello, Roger L." <costello@mitre.org>