Saxon

<?xml version="1.0" encoding="UTF-8"?>

<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"

xmlns:xs="http://www.w3.org/2001/XMLSchema"

xmlns:saxon="http://saxon.sf.net/"

exclude-result-prefixes="#all"

expand-text="yes"

version="3.0">

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

<xsl:accumulator name="items" as="element(item)*" initial-value="()" streamable="yes">

<xsl:accumulator-rule phase="end" match="item" select="$value, ." saxon:capture="yes"/>

</xsl:accumulator>

<xsl:template match="item">

<xsl:next-match/>

<xsl:message>item: {string(@id)}, count(accumulator-after("items")): {count(accumulator-after('items'))}, accumulator-after("items")!@id!string(): {accumulator-after("items")!@id!string()}</xsl:message>

</xsl:template>

</xsl:stylesheet>