Find missing values in range.

[BillMoo]

Hi,

Given this fragment from an XML document:

<range>
            <value from="12" to="14" output="400" />
            <value from="15" to="21" output="730" />
            <value from="22" to="28" output="433" />
            <value from="29" to="80" output="230" />
            <value from="83" to="85" output="220" />
            <value from="86" to="122" output="320" />
</range>

I would like to find out what values are missing from a known range. In this case I know the range of the from / to attributes to be 1 to 168 inclusive so I can see simply by looking that I am missing 1 to 11, 81 to 82 and 123 to 168 easy enough, but I want to produce an XSLT transformation that will tell me this. Needless to say I've googled and I can't really come up with a concrete sample so I thought I would ask here.

Is anyone able to help me out here? If not maybe you know of a generic XML/XSLT forum where I could re-post this.

--
Thank you,

Moo.

 

[tsuji]

[0] I assume the well-ordering of intervals that some kind of assumptions on the non-overlapping of intervals.

[1] If they are kind of well-ordering in the sense of [0], the following shows you how those non-covered intervals can be exposed, within the xslt 1.0 pure.
[tt]
<xslutput method="text" omit-xml-declaration="yes" />
<xsl:strip-space elements="*" />
<xslaram name="m">1</xslaram>
<xslaram name="M">168</xslaram>
<xsl:template match="/root">
<xsl:apply-templates select="value">
<xsl:sort select="@from" data-type="number" order="ascending" />
</xsl:apply-templates>
</xsl:template>
<xsl:template match="value">
<xsl:call-template name="proc">
<xsl:with-param name="mproc" select="preceding-sibling::value[1]/@to" />
<xsl:with-param name="Mproc" select="following-sibling::value[1]/@from" />
</xsl:call-template>
</xsl:template>

<xsl:template name="proc">
<xslaram name="mproc" />
<xslaram name="Mproc" />
<xsl:choose>
<xsl:when test="not(number($mproc)) and (number(@from) &gt; number($m))">
<xsl:value-of select="concat(number($m),'-',(number(@from) - 1))" />
</xsl:when>
<xsl:when test="not(number($Mproc)) and (number(@to) &lt; number($M))">
<xsl:value-of select="concat((number(@to)+1),'-', number($M))" />
</xsl:when>
<xsltherwise>
<xsl:choose>
<xsl:when test="(number(@from)-1) &lt; (number($mproc)+1)">
<!-- do nothing -->
</xsl:when>
<xsltherwise>
<xsl:value-of select="concat(',',(number($mproc)+1),'-', (number(@from)-1),',')" />
</xsltherwise>
</xsl:choose>
</xsltherwise>
</xsl:choose>
</xsl:template>
[/tt]