RE: [xsl] parameter default for xsl:function?

["Michael Kay" <mike@xxxxxxxxxxxx>]

User-defined functions are designed to be context-free: all arguments have
to be passed explicitly, and they have no access to the context item at the
point of the call. In this sense they differ from system-defined functions
like name() and position().

The reason for this is to allow optimizations of the kind that are common in
functional programming languages. It is a bit inconsistent though.

Thanks for the nice words about Saxon.

Michael Kay
http://www.saxonica.com/

> -----Original Message-----
> From: Joern Nettingsmeier [mailto:nettings@xxxxxxxxxxxxxxxxxxxxxx]
> Sent: 26 February 2006 16:41
> To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> Subject: [xsl] parameter default for xsl:function?
>
> hi!
>
>
> i'm playing around with xsl 2.0 atm, and i'm wondering: is it
> possible
> to define functions that operate on a node in such a way that they
> default to the current one if the parameter list is empty?
>
> "current()" inside a function is not the way to do it, since saxon
> complains that there is no context item defined at this point, which
> sounds convincing ;)
>
> i remember reading in the spec that both polymorphism and
> variable-length argument lists are not supported, but i
> wonder: how do
> the internal xpath 1.0 functions do it? e.g.:
>
> concat(<string>, <string> [,<string>]+)
>
> name([<node>])
>
>
> btw, xsl 2 is really a huge improvement, thanks a bunch to all
> contributors, and to dr. kay for the saxon implementation!
>
>
> regards,
>
>
> jvrn
>
>
>
> --
> jvrn nettingsmeier
>
> home://germany/45128 essen/lortzingstr. 11/
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>
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