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Re: [xsl] Proposal: Copying with Sorting

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> <xsl:copy-of select="sort('sk1', exp)"/>

I hope that I'm wrong, but it seems to me that the above will create a
sorted node-set (sort()) and then copy it once again (xsl:copy-of).

This shows that  

<xsl:copy-of select="sort('sk1', exp)"/>

and the proposed:

<xsl:copy-of select="expression" sort="expression2" />

have a considerably different observable behaviour, the latter being
more efficient without needing additional optimisations. It also does
not have the restrictions following from the global scope of a sort
key.


=====
Cheers,

Dimitre Novatchev.
http://fxsl.sourceforge.net/ -- the home of FXSL



"Michael Kay" <michael.h.kay@xxxxxxxxxxxx> wrote in message
news:001b01c2b4ea$0db30c20$6601a8c0@xxxxxxxxxx
> XSLT 2.0 allows you to create a sorted sequence of nodes using the
> sort() function, with named sort keys:
> 
> <xsl:sort-key name="sk1">
>   <xsl:sort select="exp2"/>
> </xsl:sort-key>
> 
> <xsl:copy-of select="sort('sk1', exp)"/>
> 
> Michael Kay
> Software AG
> home: Michael.H.Kay@xxxxxxxxxxxx
> work: Michael.Kay@xxxxxxxxxxxxxx 
> 
> > -----Original Message-----
> > From: owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx 
> > [mailto:owner-xsl-list@xxxxxxxxxxxxxxxxxxxxxx] On Behalf Of 
> > Dimitre Novatchev
> > Sent: 05 January 2003 09:01
> > To: xsl-list@xxxxxxxxxxxxxxxxxxxxxx
> > Subject: [xsl] Proposal: Copying with Sorting
> > 
> > 
> > I would like to propose a simplification of the most widely 
> > used case of sorting, when a the members of a node-set are 
> > simply copied in a different order.
> > 
> > The proposal is to allow xsl:sort to be a child of xsl:copy-of.
> > 
> > Thus instead of writing [1]:
> > 
> > <xsl:for-each select="expression"> 
> >   <xsl:sort select="expression2"/> 
> >   <xsl:copy-of select="."/> 
> > </xsl:for-each> 
> > 
> > 
> > one would simply write [2]:
> > 
> > <xsl:copy-of select="expression">
> >   <xsl:sort select="expression2"/> 
> > </xsl:copy-of> 
> > 
> > 
> > What are the advantages of having [2]?
> > 
> > 1. The new instruction is more compact and simpler.
> > 
> > 2. It reflects the principle that it should be possible to do
simple 
> >    things in a simple way.
> > 
> > 3. Shorter, simpler, more readable and maintainable xslt code.
> > 
> > 4. Probably allows a more efficient implementation.
> > 
> > 5. The programmer will not have to worry whether to use (gasp!) an 
> >    xsl:for-each or an xsl:apply-templates with or without mode.
> > 
> > 6. Eliminates the vast number of programming errors, when the 
> >    programmer simply forgets to specify  <xsl:copy-of 
> > select="."/>  in 
> >    [1]
> > 
> > 
> > A further simplification will be achieved if a "sort" 
> > attibute is allowed in case of sorting on a single key only. 
> > 
> > Then we could write [3]:
> > 
> > <xsl:copy-of select="expression" sort="expression2" />
> > 
> > 
> > I would appreciate receiving any comments on this proposal. 
> > Would you like to have this feature proposed for inclusion in 
> > XSLT 2.0?
> > 
> > 
> > 
> > 
> > =====
> > Cheers,
> > 
> > Dimitre Novatchev.
> > http://fxsl.sourceforge.net/ -- the home of FXSL
> > 
> > __________________________________________________
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