Question

I have this XML file:

<Elements>
  <Element name="A.B.C.x">
    <Child>...</Child>
    <Child>...</Child>
    <Child>...</Child>
  </Element>
  <Element name="A.B.C.y">
    <Child>...</Child>
    <Child>...</Child>
  </Element>
  <Element name="A.D.E.y">
    <Child>...</Child>
  </Element>
  <Element name="A.D.E.z">
    <Child>...</Child>
    <Child>...</Child>
    <Child>...</Child>
  </Element>
</Elements>

I need to create XSL to get this result:

<Elements>
  <Element name="A.B.C">
    <LastToken name="x" childCount="3" />
    <LastToken name="y" childCount="2" />
  </Element>
  <Element name="A.D.E">
    <LastToken name="y" childCount="1" />
    <LastToken name="z" childCount="3" />
  </Element>
</Elements>

I am limited to XSL 1.0 with no extensions and I cannot figure out how to achieve the result.

Any help appreciated.
Thanks in advance.

EDIT: As some answers came in I saw I have to clarify my question/task:
Tokens in name attribute of Element node are not limited to one character. Sample value of ‘name’ attribute could be This.Is.Grouping.Target.AndThisIsGroupChild

Answer 1

Just for fun, a general XSLT 1.0 solution without extensions:

<!DOCTYPE xsl:stylesheet [
  <!ENTITY key "
substring(
   @name,
   1,
   string-length(
      @name
   )
 - count(
      document('')//node()[
         not(
            contains(
               substring(
                  current()/@name,
                  string-length(
                     current()/@name
                  )
                - position()
                + 1
               ),
               '.'
            )
         )
      ]
   )
 - 1
)">
]>
<xsl:stylesheet version="1.0" xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
    <xsl:key name="kElementByNamePrefix" match="Element" use="&key;"/>
    <xsl:key name="kElementByName" match="Element" use="@name"/>
    <xsl:template match="Element">
        <xsl:variable name="vNamePrefix" select="&key;"/>
        <xsl:variable name="vCurrentGroup"
         select="key('kElementByNamePrefix',$vNamePrefix)"/>
        <xsl:if test="generate-id() = generate-id($vCurrentGroup[1])">
            <Element name="{$vNamePrefix}">
                <xsl:apply-templates
                 select="$vCurrentGroup[
                            generate-id()
                          = generate-id(
                               key('kElementByName',@name)[1]
                            )
                         ]"
                 mode="prefix">
                    <xsl:with-param name="pNamePrefix" select="$vNamePrefix"/>
                </xsl:apply-templates>
            </Element>
        </xsl:if>
    </xsl:template>
    <xsl:template match="Element" mode="prefix">
        <xsl:param name="pNamePrefix"/>
        <LastToken name="{substring(substring-after(@name,$pNamePrefix),2)}"
                   childCount="{count(key('kElementByName',@name)/Child)}"/>
    </xsl:template>
</xsl:stylesheet>

Output:

<Element name="A.B.C">
    <LastToken name="x" childCount="3" />
    <LastToken name="y" childCount="2" />
</Element>
<Element name="A.D.E">
    <LastToken name="y" childCount="1" />
    <LastToken name="z" childCount="3" />
</Element>