Re: Crazy idea

[Francis Norton <francis@xxxxxxxxxxx>]

Oren Ben-Kiki wrote:
> 
> Francis Norton <francis@xxxxxxxxxxx> wrote:
> > Oren Ben-Kiki wrote:

...

> 
> > I would add another objection - I'm not sure that XSLT is powerful
> > enough to do the data-validation (as opposed to the structure
> > validation) unless/until it gets regular expressions.
> 
> Some sort of order constraints on sub elements are obviously useful. Simple
> sequences with optional repeating elements are trivial to express in XSLT
> (though not as elegantly as in XSchemas, I admit). Anything further becomes
> hairy, but it isn't clear to me that much more is useful in practice.
> 
> I don't see any easy way to add regular expressions to XSLT.
> 

It's on the list of possible extensions -
http://www.w3.org/TR/xslt#section-Features-under-Consideration-for-Future-Versions-of-XSLT

> > On a less fundamental note, I'd also like the ability to define XSLT
> > functions in XSLT, which would make programs very
> > much more concise and legible.
> 
> You can, using "named templates".
> 

Yes, but a function call typically takes a single line, maybe less than
one line. If I'm trying to keep my code legible then each parameterised
named template call will take about 2+n lines where n is the number of
parameters; eg:

	<!-- generate and implictly pass back a result object -->
	<xsl:call-template name="valid-choice">
		<xsl:with-param name="tree-count" select="$tree-count" />
		<xsl:with-param name="content-list" select="$content-list" />
		<xsl:with-param name="valid-pattern" select="$valid-pattern" />
	</xsl:call-template>
			
v.

	<!-- [hypothetical syntax] generate and implictly pass back a result
object -->
	fn:valid-choice($tree-count, $content-list, $valid-pattern)

Cheers -

Francis.


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