Formatting the output of the sum() function in XQuery/XSLT/XPath

I have a question about formatting the output of the sum() function in XQuery/XSLT/XPath. I have both an XSLT stylesheet and also an XQuery. I'm able to get the correct formatting in the XSLT, but not in the XQuery.

Here is an example input file:

<userTotals>
  <user cost="138764.63" hours="1506.51"/>
  <user cost="329555.76" hours="3577.85"/>
  <user cost="213909.81" hours="2322.33"/>
  <user cost="22684.85" hours="246.28"/>
  <user cost="6147.42" hours="66.74"/>
  <user cost="1269.27" hours="13.78"/>
  <user cost="181.45" hours="1.97"/>
  <user cost="755.30" hours="8.2"/>
</userTotals>

Here is an example stylesheet:

<xsl:stylesheet version="2.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
  <xsl:output indent="yes"/>
  <xsl:strip-space elements="*"/>

  <xsl:template match="/userTotals">
    <results>
      <cost><xsl:value-of select="sum(user/@cost)"/></cost>
      <hours><xsl:value-of select="sum(user/@hours)"/></hours>
      <hours-formatted>
        <xsl:value-of select="format-number(sum(user/@hours),'###.##')"/>
      </hours-formatted>
    </results>
  </xsl:template>

</xsl:stylesheet>

Here is the output:

<results>
   <cost>713268.49</cost>
   <hours>7743.659999999999</hours>
   <hours-formatted>7743.66</hours-开发者_运维知识库formatted>
</results>

Notice the output of <hours> and <hours-formatted>. The content of <hours> is the unmodified/unformatted output of sum(). The content of <hours-formatted> is the way I want the number formatted in both the XSLT and the XQuery.

The problem is that in XQuery, format-number() is not available. How can I format the results of sum() the same way in both XSLT and XQuery so that the results will appear like <hours-formatted>?

Will I need to create a function that takes the output of sum() as a string and process the decimal myself? In this case I would need to round .659 to .66. I'm hoping there is a better way to do this (maybe cast the results as a different type and then ??).

Thank you for any info/guidance you can provide.

Saxon-PE and upwards offers format-number() in XQuery as an extension function (or by enabling XQuery 3.0 support).

But you can probably achieve what you want using the round-half-to-even() function.

This XQuery expression:

let $sum := string(ceiling(sum(/*/user/@hours) * 100)),
    $length := string-length($sum)
return
  concat(
     substring($sum, 1, $length - 2),
     '.',
     substring($sum, $length - 1)
  )

Output:

7743.66