On Wed, 14 Feb 2001, David Carlisle wrote:
> > If I use tags that are not in the XSL namespace then its not 100% xsl is it.
> > its XSL + saxon extensions. Its still valid XSL but its not 100% pure BC
> > grown XSL. 
> 
> that is still true with 1.1's xsl:script. If you don't use functions or
> elements in an extension namespace then the xsl file is portable. No
> matter how many xsl:script elements you might have used.

It seems that many of us think that extension functions are 
"acceptable", where xsl:script is a horse of a completely 
different color:

  Extension functions specify particular functionality
  be carried out, and do not specify an implementation.
  For each extension function, a small and seperate specification
  can be laid out describing the intent of the function.
  Implementations can provide this functionality *independent*
  of the language the XSLT processor is written in.  
  With an extension function, I can enumerate what exact
  functions are needed; this implies that it is completely
  acceptable to implement just a few functions of a given type.

  Scripts are embedded code of a completely different language
  with it's own interpreter, etc.  Certainly one could write
  an implementation of each interpreter independent of the
  language; but writing function vs writing a full-fledged
  interpreter is a big leap in complexity.  With scripts, 
  it is implied that a full implementation of the interpreter
  is availabele.  Thus, enumeration of additional required
  functionality is a very hard problem.

As such, extension functions provide a nice "layer" between
the XSLT script and the transform; with scripts the layering
is given up altogether.  I think scripts are an ill-advised move,
all bets at cross-platform compatibilty go out the door.

Many people want scripts beacuse the "modulization" abilities
of XSLT leave alot to be desired, i.e., making a template and
calling a template are just too verbose.  This seperate issue
can be solved by an additional namespace "xf" with the following
behavior:

Anywhere, except as a child of "xsl:template",

  <xf:func x="y" />    is equivalent to   <xsl:call-template name="func">
                                            <xsl:with-param name="x"
                                               select="y" />
                                          </xsl:call-template>

and when a child of xsl:template,

  <xf:func x="y">      is equivalent to   <xsl:template name="func">
    ...                                     <xsl:param name="x"
  </xf:func>                                    select="y" />
                                            ...
                                          </xsl:template>


Clark


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