Re: functions and sequences

I've also run into this issue.

While it is perfectly understandable, it is a major change from
XSLT/XPath 1.0 where it was not allowed to have two immediate
text-node siblings.

Now we have sequences and we can have a sequence of text nodes.

I think it would be good to support the following in order to avoid
inconvenience and confusion:

   -  Allow an xs:string() constructor, which takes a sequence of
xs:strings or a sequence of text nodes; This will allow a function of
type xs:string to automatically convert a sequence of
strings/text-nodes to a single string return value.

   - Provide an overload of the concat() function, which takes a
single argument of type sequence of xs:string or sequence of text
nodes.


Cheers,
Dimitre.


On Mon, 13 Dec 2004 00:02:02 -0000, Michael Kay <mike@xxxxxxxxxxxx> wrote:
> <xsl:text> constructs a text node; if you have several <xsl:text> and/or
> <xsl:value-of> instructions in your function, then the result of the
> function is a sequence of text nodes. A sequence of text nodes can't be
> automatically converted to a string.
> 
> One solution is to generate the output using XPath expressions instead:
> 
> <xsl:sequence select="
>  if ($bibref/mods:relatedItem/@type = 'host')
>  then concat('article-', $bibref/mods:relatedItem/mods:genre)
>  else ....
> "/>
> 
> Another solution is to wrap the various xsl:text and xsl:value-of
> instructions in a containing <xsl:value-of>
> 
> <xsl:value-of>
>  <xsl:choose>
>    ...
>  </xsl:choose>
> </xsl:value-of>
> 
> This way the function returns a single text node, which is automatically
> converted to a single string if the declared return type is xs:string.
> 
> Michael Kay
> http://www.saxonica.com/
> 
> 
> 
> > -----Original Message-----
> > From: Bruce D'Arcus [mailto:bdarcus@xxxxxxxxxxxxx]
> > Sent: 12 December 2004 23:09
> > To: XSL-List@xxxxxxxxxxxxxxxxxxxxxx
> > Subject:  functions and sequences
> >
> > I've run across this issue in a different context, but can't
> > figure out
> > how to apply it here.
> >
> > I have this function (within a large stylesheet).  It works if I
> > comment out the two lines indicated with the comments, but I get a "E
> > net.sf.saxon.xpath.DynamicError: A sequence of more than one item is
> > not allowed as the result of function bib:reftype()" error
> > otherwise.
> > Is there some way to get this to work?  I'm not really sure
> > how much of
> > the related code I need to show to have this make any sense!
> >
> >    <xsl:function name="bib:reftype" as="xs:string">
> >      <xsl:param name="bibref" as="element(mods:mods)?"/>
> >      <xsl:choose>
> >        <xsl:when test="$bibref/mods:relatedItem/@type = 'host'">
> >          <xsl:variable name="issuance"
> > select="$bibref/mods:relatedItem/mods:originInfo/mods:issuance"/>
> >          <xsl:choose>
> >            <xsl:when test="bib:refclass($bibref) = 'part-inSerial'">
> >              <xsl:text>article</xsl:text>
> >              <!-- this code introduces a sequence error;
> > don't know why
> > -->
> >              <xsl:text>-</xsl:text>
> >              <xsl:value-of
> > select="$bibref/mods:relatedItem/mods:genre"/>
> >            </xsl:when>
> >            <xsl:when test="bib:refclass($bibref) =
> > 'part-inMonograph'">
> >              <xsl:choose>
> >                <xsl:when test="$bibref/mods:genre">
> >                  <xsl:value-of select="$bibref/mods:genre"/>
> >                </xsl:when>
> >                <xsl:otherwise>
> >                  <xsl:text>chapter</xsl:text>
> >                </xsl:otherwise>
> >              </xsl:choose>
> >            </xsl:when>
> >            <xsl:otherwise>
> >              <xsl:value-of select="$bibref/mods:genre"/>
> >            </xsl:otherwise>
> >          </xsl:choose>
> >        </xsl:when>
> >        <xsl:otherwise>book</xsl:otherwise>
> >      </xsl:choose>
> >    </xsl:function>