Re: [xsl] Recursive string replace in XSLT 2.0

["Michael Kay mike@xxxxxxxxxxxx" <xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx>]

If you don't like head-tail recursion for this kind of problem, there are a
couple of alternatives you might consider.

One is xsl:iterate, which looks something like this:

<xsl:iterate select="$list-of-replacements">
  <xsl:param name="str" as="xs:string"/>
  <xsl:on-completion select="$str"/>
  <xsl:next-iteration>
    <xsl:with-param name="str" select="replace($str, find, change)"/>
  </xsl:next-iteration>
</xsl:iterate>

The other is fold-left:

fold-left($list-of-replacements, $str, function($str, $regex) { replace($str,
$regex/find, $regex/change) } )

Both these require 3.0.

Michael Kay
Saxonica


> On 6 Jan 2017, at 19:41, David Carlisle d.p.carlisle@xxxxxxxxx
<xsl-list-service@xxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> I'd have written it as a function rather than template, but the main
> issue is you want your parameter to be (always) a sequence of elements
> not sometimes a sequence of elements and sometimes a document node
> with a sequence of child elements.
>
> <?xml version="1.0" encoding="UTF-8"?>
> <xsl:stylesheet xmlns:xsl="http://www.w3.org/1999/XSL/Transform";
>    xmlns:xs="http://www.w3.org/2001/XMLSchema";
>    exclude-result-prefixes="xs"
>    version="2.0">
>
>    <xsl:output indent="yes"/>
>
>    <xsl:param name="regexes">
>        <regex><find>a</find><change>x</change></regex>
>        <regex><find>b</find><change>y</change></regex>
>        <regex><find>c</find><change>z</change></regex>
>    </xsl:param>
>
>    <xsl:template match="/">
>        <xsl:apply-templates/>
>    </xsl:template>
>
>    <xsl:template match="p">
>        <p><xsl:apply-templates/></p>
>    </xsl:template>
>
>    <xsl:template match="text()"><!--[string-length(.)>0]-->
>        <xsl:message select="."></xsl:message>
>        <xsl:call-template name="applyRegexes">
>            <xsl:with-param name="nodeText" select="."/>
>            <xsl:with-param name="regex" select="$regexes/regex"/>
>         </xsl:call-template>
>    </xsl:template>
>
>    <xsl:template name="applyRegexes">
>        <xsl:param name="nodeText"/>
>        <xsl:param name="regex"/>
>        <xsl:message select="$regex"></xsl:message>
>        <xsl:message select="$regex[1]"/>
>        <xsl:message select="$regex[position()>1]"/>
>        <xsl:choose>
>            <xsl:when test="$regex">
>                <xsl:call-template name="applyRegexes">
>                    <xsl:with-param name="nodeText"
> select="replace($nodeText,$regex[1]/find,$regex[1]/change)"/>
>                    <xsl:with-param name="regex"
> select="$regex[position()>1]"/>
>                </xsl:call-template>
>            </xsl:when>
>            <xsl:otherwise>
>                <xsl:value-of select="$nodeText"/>
>            </xsl:otherwise>
>        </xsl:choose>
>     </xsl:template>
>
> </xsl:stylesheet>