On 22.10.2019 20:07, Rick Quatro rick@xxxxxxxxxxxxxx wrote:

I am using XSLT 2 and think this may require a for-each-group solution.
Any advice would be appreciated. Thank you very much.

As an alternative, if you can move to XSLT 3, then I think it is also
easy with "xsl:iterate":

Thinking about it again, it seems in XSLT 3 simply using an accumulator
makes it even more easy and compact:

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    exclude-result-prefixes="#all"
    version="3.0">

    <xsl:mode on-no-match="shallow-copy" streamable="yes"
use-accumulators="rev-change"/>

    <xsl:accumulator name="rev-change" as="xs:boolean"
initial-value="false()" streamable="yes">
        <xsl:accumulator-rule match="topic" select="false()"/>
        <xsl:accumulator-rule match="topic/revst" select="true()"/>
        <xsl:accumulator-rule match="topic/revend" select="false()"/>
    </xsl:accumulator>

    <xsl:template match="topic/*[accumulator-before('rev-change')]">
        <xsl:copy>
            <xsl:attribute name="rev">changed</xsl:attribute>
            <xsl:apply-templates select="@*"/>
            <xsl:apply-templates/>
        </xsl:copy>
    </xsl:template>

Saxon EE however doesn't like it for streaming and crashes, works fine
however with HE or with EE and streaming turned off.