Sequence number of different nodes

I have an XML file with many nodes, and each different node has to have a sequence number. How can I achieve this with XSLT 3.0?

Input example:

<root>
    <a>x</a>
    <a>x</a>
    <c>x</c>
    <d>x</d>
    <a>x</a>
    <c>x</c>
    <d>x</d>
    <b>x</b>
    <a>
        <x>.</x>
        <b>.</b>
    </a>
</root>

Output example:

<root serial='1'>
    <a serial='1'>x</a>
    <a serial='2'>x</a>
    <c serial='1'>x</c>
    <d serial='1'>x</d>
    <a serial='3'>x</a>
    <c serial='2'>x</c>
    <d serial='2'>x</d>
    <b serial='1'>x</b>
    <a serial='4'>
        <x serial='1'>.</x>
        <b serial='2'>.</b>
    </a>
</root>

CodePudding user response：

You should be able to use xsl:number to do this...

<xsl:stylesheet version="3.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:output indent="yes"/>
    <xsl:strip-space elements="*"/>
    
    <xsl:mode on-no-match="shallow-copy"/>
    
    <xsl:template match="*">
        <xsl:copy>
            <xsl:attribute name="serial">
                <xsl:number/>
            </xsl:attribute>
            <xsl:apply-templates select="@*|node()"/>
        </xsl:copy>
    </xsl:template>
    
</xsl:stylesheet>

Working example: http://xsltfiddle.liberty-development.net/gVTWaA4/2