I have these two scripts. I wrote them to test if libxslt support tail recursion optimization. I know now that it does not, but I did find some behavior I do not understand in the process. The first script works when num is set to 2998, but fails when it is higher with a message about max depth being 3000... The second script fails when num is set to 1875, but there is no error. A debug/verbose is not showing me any errors. Now I know that libxslt can sum up to 2998 = 4495501. The sum through 1874 is 1756875. So its not like the the number is getting too big. Can someone help me understand this?
###script 1#### <?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; version="1.0"> <xsl:template match="/"> <output> <xsl:call-template name="additup"> <xsl:with-param name="num" select="3000"/> </xsl:call-template> </output> </xsl:template> <xsl:template name="additup"> <xsl:param name="sum_acc" select="0"/> <xsl:param name="num" select="0"/> <xsl:choose> <xsl:when test="$num = 0"> <xsl:value-of select="$sum_acc"/> </xsl:when> <xsl:otherwise> <xsl:call-template name="additup"> <xsl:with-param name="sum_acc" select="$sum_acc + $num"/> <xsl:with-param name="num" select="$num - 1"/> </xsl:call-template> </xsl:otherwise> </xsl:choose> </xsl:template> </xsl:stylesheet> ################ ####script 2######### <?xml version="1.0" encoding="UTF-8"?> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform"; version="1.0"> <xsl:template match="/"> <output> <xsl:call-template name="additup"> <xsl:with-param name="num" select="1875"/> </xsl:call-template> </output> </xsl:template> <xsl:template name="additup"> <xsl:param name="num" select="0"/> <xsl:choose> <xsl:when test="$num = 0"> <xsl:value-of select="0"/> </xsl:when> <xsl:otherwise> <xsl:variable name="tailsum"> <xsl:call-template name="additup"> <xsl:with-param name="num" select="$num - 1"/> </xsl:call-template> </xsl:variable> <xsl:value-of select="$num + $tailsum"/> </xsl:otherwise> </xsl:choose> </xsl:template> </xsl:stylesheet> ######################## _______________________________________________ xslt mailing list, project page http://xmlsoft.org/XSLT/ [email protected] http://mail.gnome.org/mailman/listinfo/xslt
