<xsl:template match="p">
  <p>
    <xsl:call-template name="merge-spans"/>
  </p>
</xsl:template>

<xsl:template name="merge-spans">
  <xsl:for-each-group select="node()" group-adjacent="m:class(.)">
    <xsl:choose>
      <xsl:when test="string(current-grouping-key())">
        <span class="{current-grouping-key()}">
          <xsl:apply-templates
            select="current-group()" mode="merged"/>
        </span>
      </xsl:when>
      <xsl:otherwise>
        <xsl:apply-templates select="current-group()"/>
      </xsl:otherwise>
    </xsl:choose>
  </xsl:for-each-group>
</xsl:template>

<xsl:function name="m:class" as="xs:string">
  <!-- returns a class value for a span, or the class value of an
  immediately preceding span for whitespace-only text,
  comment or PI nodes -->
  <xsl:param name="s" as="node()"/>
  <xsl:sequence select="($s/self::span/@class,
    $s/(self::text()[not(normalize-space())] |
        self::comment() |
        self::processing-instruction() )/
       preceding-sibling::*[1][self::span]/@class,
    '')[1]"/>
</xsl:function>

<xsl:template match="node()" mode="merged">
  <xsl:apply-templates select="."/>
</xsl:template>

<xsl:template match="span[@class]" mode="merged">
  <xsl:apply-templates/>
</xsl:template>

Cheers,
Wendell

<p><span class="strong-emphasis">Fome</span> <span class="strong-emphasis">Zero</span>
        <span class="strong">: la stratigie du Brisil pour risoudre les problhmes de l'insicuriti alimentaire et de la faim </span></p>

And also:

<p><span class="strong">C</span><span class="strong">ontexte</span></p>

I need to merge those spans with identical class attribute values along with the whitespace to get something like:

<p><span class="strong-emphasis">Fome Zero</span>
        <span class="strong">: la stratigie du Brisil pour risoudre les problhmes de l'insicuriti alimentaire et de la faim </span></p>

And:

<p><span class="strong">Contexte</span></p>

--
======================================================================
Wendell Piez                            mailto:wapiez@xxxxxxxxxxxxxxxx
Mulberry Technologies, Inc.                http://www.mulberrytech.com
17 West Jefferson Street                    Direct Phone: 301/315-9635
Suite 207                                          Phone: 301/315-9631
Rockville, MD  20850                                 Fax: 301/315-8285
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  Mulberry Technologies: A Consultancy Specializing in SGML and XML
======================================================================