Re: [xml-dev] When you create a markup language, what do your parentelem

[David Carlisle <davidc@nag.co.uk>]

On 26/09/2011 14:18, Costello, Roger L. wrote:
> Would you state the meanings of each of those please?

I don't think there is any particular meaning attached to the fact that
one element is a child of another. It's just an essentially arbitrary
syntax choice. In some cases they could have been attributes instead of
elements, in some cases they could not, but that is only because
attributes can not contain structure whereas elements can, so the choice
to use a child element is driven by xml syntax rules rather than any
properties of the thing that is being modelled in the XML.


In particular

> That is, does it mean that "stylesheet" is an object and "template"
> is
its property?

No.

It means that the design of xslt requires that there are more than one
template, and the rules of xml syntax mean there has to be single top
level element, so the templates get wrapped in xsl:stylesheet. Once that
element is added to match xml syntactic constraints it may as well be
used to hang other information such as version etc.

Even within a single element there may be little to no similarity
between the relationships expressed, it just depends on the rules of the
vocabulary being used.

<xsl:for-each...
<xsl:sort ../>
<p>...</p>
</xsl:for-each>


both xsl:sort and <p> are children of xsl:for-each but the relationships
couldn't be more different.

in mathml

<apply><sin/><mn>0</mn></apply>

The two child elements are related rather differently to their parent.
But it doesn't really tell you anything about what the underlying
objects "mean", It could (with perhaps some loss of flexibility) have
been defined to use the syntax

<sin><mn>0</mn></sin>

the fact that it uses the former is a syntactic design choice in MathML,
it doesn't tell you anything about the relationships between the
concepts of function application, the sine function, and the number 0.

David






David


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