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Re: [xsl] A nice way to implement the ANDing of the comparison of pairs of items in a sequence?


Subject: Re: [xsl] A nice way to implement the ANDing of the comparison of pairs of items in a sequence?
From: Adam Retter <adam.retter@xxxxxxxxxxxxxx>
Date: Thu, 5 Sep 2013 20:56:46 +0100

If you have access to an XSLT processor, you could do something like
the following. Note that I have not thoroughly checked the Syntax as I
do not have an XSLT 3 processor.


<xsl:stylesheet
    xmlns:xsl="http://www.w3.org/1999/XSL/Transform"
    xmlns:xs="http://www.w3.org/2001/XMLSchema"
    xmlns:f="http://function"
    version="3.0">

    <xsl:output method="xml"/>

    <xsl:variable name="checkPairs"
        select="('Sally', 'Sally', 'Beth', 'beth', 'Mary', 'Mary')"
as="xs:string*"/>

    <xsl:template match="/">
        <!-- split the checkPairs sequence into two sequences -->
        <xsl:variable name="sq1" select="$checkPairs[position() mod 2 != 0]"/>
        <xsl:variable name="sq2" select="$checkPairs[position() mod 2 = 0]"/>

        <!-- compare the two sequences -->
        <xsl:variable name="results" select="for-each-pair($sq1, $sq2,
f:string-equal)"/>

        <!-- reduce the results -->
        <xsl:variable name="result" select="fold-left($results,
true(), f:and)"/>

    </xsl:template>


    <xsl:function name="f:string-equal">
        <xsl:param name="a" as="xs:string"/>
        <xsl:param name="b" as="xs:string"/>
        <xsl:value-of select="$a eq $b"/>
    </xsl:function>

    <xsl:function name="f:and">
        <xsl:param name="a" as="xs:boolean"/>
        <xsl:param name="b" as="xs:boolean"/>
        <xsl:value-of select="$a and $b"/>
    </xsl:function>

</xsl:stylesheet>

On 5 September 2013 19:51, Costello, Roger L. <costello@xxxxxxxxx> wrote:
> Hi Folks,
>
> The value of this variable is a sequence of strings:
>
> <xsl:variable name="checkPairs"
>      select="('Sally', 'Sally', 'Beth', 'Beth', 'Mary', 'Mary')" as="xs:string*"/>
>
> I want to compare consecutive items and then AND the result of the comparisons.
>
> That is, compare the first string to the second string, the third string to the fourth string, the fifth string to the sixth string, and so on. Then AND the results together.
>
> Thus,
>
>     ('Sally' eq 'Sally') and ('Beth' eq 'Beth') and ('Mary' eq 'Mary')
>
> returns true.
>
> But if the variable is this:
>
> <xsl:variable name="checkPairs"
>      select="('Sally', 'Beth', 'Beth', 'Beth', 'Mary', 'Mary')" as="xs:string*"/>
>
> the result is false since
>
>     ('Sally' eq 'Beth') and ('Beth' eq 'Beth') and ('Mary' eq 'Mary')
>
> is false.
>
> Is there a nice way to implement this?
>
> /Roger
>



-- 
Adam Retter

skype: adam.retter
tweet: adamretter
http://www.adamretter.org.uk


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