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Re: [xsl] tokenize() and regex-group ?

Subject: Re: [xsl] tokenize() and regex-group ?
From: Matthieu Ricaud-Dussarget <matthieu.ricaud@xxxxxxxxx>
Date: Tue, 17 Jul 2012 16:54:13 +0200

Thank you Michael.

At first I used <xsl:analyze-string> before I realized I have to check for one *or more* words to match the definition.
I thought using tokenize would help with going back reccursively from word to word into the string (help by position() predicates).
But well I did not thought about problems with differents separator pattern (the igs:match-ancre() function is permissive with this... but the output tagging is not good, eg. <link idref="#foobar">B+ foo bar*</link> B; shall better be B+ <link idref="#foobar">foo bar*</link> B;).

As usual you're right :-) I have to go back with <xsl:analyze-string>

The problem I suspected was about a regex witch match 1 or 2 or N words, something like $wordRegex$sepRegex{{$lookBacklevel}}

After your emphazing fn:tokenize(), I finaly started with another way of doing it with the help of af function that tokenize as XML :

<xsl:function name="igs:tokenize-as-xml" as="element()*">
<xsl:param name="string" as="xs:string"/>
<xsl:param name="regex" as="xs:string"/>
<xsl:variable name="tmp" as="element()*">
<xsl:analyze-string select="$string" regex="{$regex}">
<igs:sep><xsl:value-of select="."/></igs:sep>
<igs:text><xsl:value-of select="."/></igs:text>
<xsl:for-each-group select="$tmp" group-adjacent="local-name(.)='sep'">
<xsl:when test="current-grouping-key()">
<igs:sep><xsl:value-of select="string-join(current-group(),'')"/></igs:sep>
<xsl:copy-of select="current-group()"/>

Hope I can bind everything, I tell you about this when I finish.


Le 17/07/2012 15:22, Michael Kay a C)crit :
You need to use xsl:analyze-string. I don't understand the difficulties in using this inside a recursive template. xsl:analyze-string can do everything that tokenize can do; you could implement tokenize as

<xsl:function name="fn:tokenize" as="xs:string">
  <xsl:param name="in" as="xs:string"/>
  <xsl:param name="regex" as="xs:string"/>
  <xsl:analyze-string select="$in" regex="{$regex}"/>
       <xsl:sequence select="."/>

Start be replacing your call to tokenize with a call to that function, then add whatever functionality you need.

Michael Kay

On 17/07/2012 14:02, Matthieu Ricaud-Dussarget wrote:
Hi all,

I'm tokenizing some text within a reccursiv template. The goal is to generates some linking with some "definitions" inside the doc.
Let say my text is : "my foo bar"
=> 1st level of reccursion is searching for "bar" as defined anchor in the doc
if not found, I increase a $lookBacklevel param :
=> 2nd level of reccursion is searching for "foo bar"
and so on... till it finds a matching definition or throw an error if not.
=> when a definition is found, the text is output with a link :
<p>... my <link idref="#anchorFooBar">foo bar</link> ...</p>

To do so I (space-) tokenized the text :
<xsl:variable name="tokenText" select="tokenize($text,' ')" as="xs:string*"/>

and then make 2 strings depending on reccursion param $lookBacklevel
<xsl:variable name="textBegin" select="string-join($tokenText[position() lt ($tokenNum - $lookBacklevel + 1)],' ')"/>
<xsl:variable name="textEnd" select="string-join($tokenText[position() ge ($tokenNum - $lookBacklevel + 1)],' ')"/>

I then search for a matching definition :
<xsl:variable name="matchingAncres" select="$ancres[normalize-space($textEnd)!=''][igs:match-ancre(.,$textEnd)]" as="element()*"/>
(matching rules are defined in a specific function)

The problem I've got is that the tokenize separator is too specific, it's only a space, and sometime words are separated by other char like :
- unbreakable space "&#160;"
- open parenthese "("
- french quotes "B+"
- ...

I could use a regex like "[\s(]B+" as 2nd arg of tokenize() but, I will then not be able to reconstruct the string.

So is there a way to get the separator that has been match in the regex of tokenize() ?
just like regex-group() do when using <xsl:analyze-string> ?

I think the answer is "no", but maybe I'm missing a trick to achieve this ?

I could maybe use <xsl:analyse-string> but this is not so easy because of the reccursiv template, the regex will depend on $lookBacklevel param. I'm not sure I can fin the good pattern...



Matthieu Ricaud
05 45 37 08 90
IGS-CP, service livres numC)riques

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