Re: [xsl] Multiple replace() in XSLT 2

Subject: Re: [xsl] Multiple replace() in XSLT 2
From: "Dimitre Novatchev dnovatchev@xxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>
Date: Sat, 18 May 2019 20:21:46 -0000
This was an XSLT 1.0 recursive solution:

     https://stackoverflow.com/a/5283744/36305

Based on this algorithm one can produce a non-recursive XSLT 2.0 solution
(and even a single XPath 2 expression).

Here is a first, non-polished but working non-recursive MultiReplace
implementation in XSLT 2.0 -- just 58 lines and  well-formatted. This
implementation also solves the problem of overlapping replacement patterns:

<xsl:stylesheet version="2.0" xmlns:xsl="
http://www.w3.org/1999/XSL/Transform";
 xmlns:xs="http://www.w3.org/2001/XMLSchema"; xmlns:my="my:my">
 <xsl:output omit-xml-declaration="yes" indent="yes"/>
 <xsl:strip-space elements="*"/>

    <my:params xml:space="preserve">
        <pattern>
          <old>corelation</old>
          <new>dependency</new>
        </pattern>
        <pattern>
          <old>relation</old>
          <new>tie</new>
        </pattern>
        <pattern>
            <old>&#xA;</old>
            <new><br/></new>
        </pattern>
        <pattern>
            <old>quick</old>
            <new>slow</new>
        </pattern>
        <pattern>
            <old>fox</old>
            <new>elephant</new>
        </pattern>
        <pattern>
            <old>brown</old>
            <new>white</new>
        </pattern>
    </my:params>

    <xsl:variable name="vPatterns"
         select="document('')/*/my:params/*"/>

   <xsl:template match="/">
    <xsl:sequence select="my:MultuReplace(/*)"/>
   </xsl:template>

   <xsl:function name="my:MultuReplace">
     <xsl:param name="pText" as="xs:string*"/>

     <xsl:variable name="vStartingIndexes" select=
     "for $ind in 1 to string-length($pText),
          $hasMatchingPattern in
exists($vPatterns[starts-with(substring($pText, $ind), old)])
       return
          $ind[$hasMatchingPattern]
     "/>

     <xsl:variable name="actualIndexes" select=
     "for $ind in $vStartingIndexes
       return $ind
       [position() = 1
       or
         (for $pos in position()[position() > 1],
             $prevInd in $vStartingIndexes[$pos -1],
             $prevReplacementLength in
string-length($vPatterns[starts-with(substring($pText, $prevInd),
old)][1]/old)
          return
             $prevReplacementLength le $ind - $prevInd
         )
       ]
     "/>

     <xsl:variable name="vResultSequence" as="xs:string*">
    <xsl:sequence select=
    "for $pos in  1 to count($actualIndexes),
         $indRepl in $actualIndexes[$pos],
         $startUnprocessedText in
           (if($pos = 1)
              then 1
              else
                (for $indLastReplacedText in $actualIndexes[$pos -1],
                     $last-replacedText in
$vPatterns[starts-with(substring($pText, $indLastReplacedText),
old)][1]/old,
                     $lastReplacementLength in
string-length($last-replacedText)
                    return
                      $actualIndexes[$pos -1] +
string-length($last-replacedText)
                  )
           )
      return
        ( concat(
         substring($pText, $startUnprocessedText, $indRepl -
$startUnprocessedText),
         $vPatterns[starts-with(substring($pText, $indRepl),
old)][1]/new/string()
      )
         )
    "/>

    <xsl:sequence select=
     "for $lastReplIndex in $actualIndexes[last()],
          $last-replacedText in $vPatterns[starts-with(substring($pText,
$lastReplIndex), old)][1]/old,
          $lastReplacementLength in string-length($last-replacedText)
       return
          substring($pText, $lastReplIndex + $lastReplacementLength)
     "/>
      </xsl:variable>

      <xsl:sequence select="string-join($vResultSequence, '')"/>
  </xsl:function>
</xsl:stylesheet>

When this transformation is applied on this source XML document:

<t>a corelation between a quick brown fox and a dog</t>

the wanted result is produced:

*a dependency between a slow white elephant and a dog*



Cheers,
Dimitre


On Thu, May 16, 2019 at 12:49 PM Dimitre Novatchev dnovatchev@xxxxxxxxx <
xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:

> https://stackoverflow.com/a/5283744/36305
>
> Cheers,
> Dimitre
>
> On Thu, May 16, 2019 at 11:59 AM Rick Quatro rick@xxxxxxxxxxxxxx <
> xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
>> Hi,
>>
>>
>>
>> I have a look up file of find/change pairs that I have to apply to a text
>> node in my XML document. I am using XSLT 2. Here is an example of the
>> lookup file:
>>
>>
>>
>> <?xml version="1.0" encoding="UTF-8"?>
>> <findchange_lookup>
>>     <findchange find="Eicas" change="EICAS"/>
>>     <findchange find="Ulb" change="ULB"/>
>> </findchange_lookup>
>>
>> I am reading this in as a global variable, but I am not sure the best
>> approach for doing multiple replacements on the node. I can use recursion
>> like in XSLT 1, but I can't think of how to do this in XSLT 2. There could
>> be any number of <findchange> elements in my lookup file. Any pointers
>> would be appreciated. Thank you very much.
>>
>>
>>
>> Rick
>>
>>
>>
>> Rick Quatro
>>
>> Carmen Publishing Inc.
>>
>> rick@xxxxxxxxxxxxxxx
>>
>> 585-729-6746
>>
>> www.frameexpert.com/store/
>>
>>
>>
>>
>>
>>
>>
>>
>> XSL-List info and archive <http://www.mulberrytech.com/xsl/xsl-list>
>> EasyUnsubscribe <http://lists.mulberrytech.com/unsub/xsl-list/782854> (by
>> email)
>>
>
>
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>


-- 
Cheers,
Dimitre Novatchev
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