Re: RPN calculator

If you only allow binary multiply and sum then all you need is



<xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
                version="1.0"
                >
<xsl:template match="multiply">
  <xsl:variable name="x">
   <xsl:apply-templates select="*[1]"/>
  </xsl:variable>
  <xsl:variable name="y">
   <xsl:apply-templates select="*[2]"/>
  </xsl:variable>
  <xsl:value-of select="$x1*$x2"/>
</xsl:template>

<xsl:template match="sum">
  <xsl:variable name="x">
   <xsl:apply-templates select="*[1]"/>
  </xsl:variable>
  <xsl:variable name="y">
   <xsl:apply-templates select="*[2]"/>
  </xsl:variable>
  <xsl:value-of select="$x1+$x2"/>
</xsl:template>



</xsl:stylesheet>

Although this isn't really like RPN, your input tree was a typical XML
tree structure, that relates to () and the point about RPN is that you
never need brackets or nested structure, you just have a flat stream:
 (1+2)*3=6. in RPN would be 1 2 + 3 * 

David

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