How would I translate an XML representation of a program into a target language using XSLT? (In particular, I would like to translate o:XML into PHP.)

For example, suppose we have the o:XML representation of a program (below) and would like to translate it into a PHP program (see below - may syntax and semantical errors but this will give a rough idea). Is there an example to illustrate the recursive XSLT translator that would do this. Any help would be greatly appreciated.


============ o:XML program A =================

<?xml version="1.0"?>
<program xmlns:o="http://www.o-xml.org/lang/">

    <o:type name="Translator">
      <o:parent name="Node"/>

      <o:variable name="map"/>

      <o:function name="Translator">
        <o:param name="map"/>
        <o:do/>
      </o:function>

      <o:function name="translate">
        <o:param name="nodes"/>
        <o:do>
          <o:for-each name="text" select="$nodes/*/text()">
            <o:set translated="$this.translate($text)"/>
            <o:log msg="{$text} = {$translated}"/>
            <o:do select="$text.replace($translated)"/>
          </o:for-each>
          <o:return select="$nodes"/>
        </o:do>
      </o:function>

      <o:function name="translate">
        <o:param name="text" type="String"/>
        <o:do>
          <o:return select="$map/item[from = $text]/to/text()"/>
        </o:do>
      </o:function>
    </o:type>

    <o:variable name="words">
      <item>
        <from>here</from>
        <to>aqui</to>
      </item>
      <item>
        <from>where</from>
        <to>donde</to>
      </item>
      <item>
        <from>never</from>
        <to>nunca</to>
      </item>
    </o:variable>

    <o:set translator="Translator($words)"/>

    <o:variable name="speak">
      <line>where</line>
      <word>never</word>
      <stop>here</stop>
    </o:variable>

    <o:eval select="$translator.translate($speak)"/>

    <o:for-each name="text" select="$speak/*/text()">
      <o:set translated="$translator.translate($text.string())"/>
      <o:log msg="{$text} = {$translated}"/>
      <o:do select="$text.replace($translated)"/>
    </o:for-each>

    <o:eval select="$speak"/>

    <o:log msg="here: {$translator.translate('here')}"/>

    <o:do select="$speak//text().replace('yoyo')"/>
    <o:eval select="$speak"/>

</program>

=========== XSLT Desired Result: PHP Program A ====================
<?PHP
    import "support_functions.php";

 class Translator extends Node
 {
  var $map;
  function Translator($map)
  {
   return NULL;
  }
  function translate_nodes($nodes)
  {
   foreach (selectNodes("$node/*/text()) as $key => $text)
   {
    $translated = "$this.translate($text)";
    log("{$text} = {$translated}");
    selectNodes("$text->replace($translated)");
   }
   return selectNodes("$nodes");
  }
  function translate_text($text, $type="String")
  {
   return selectNodes("$map/item[from = $text]/to/text()");
  }
 }
 $words = {{"from" => "here", "to" => "aqui"}, {"from" => "where", "to" => "donde"}, {"from" => "never", "to" => "nunca"}};
 $translator = "Translator($words)";
 $speak = {"line" => "where", "word" => "never", "stop" => "here"};
 foreach (selectNodes("$speak/*/text()") as $key => $text)
 {
  $translated = "$translator.translate($text.string())";
  log("{$text} = {$translated}");
  selectNodes("$text.replace($translated)");
 }
 eval(selectNodes("$speak"));
 log("here: {$translator.translate('here')}");
 selectNodes("$speak//text().replace('yoyo')");
 eval(selectNodes("$speak"));
?>


Philibuster

__________________
Philibuster

You might like to look at the stylesheet that converts from XQueryX into XQuery, which is a rather similar task. See http://www.w3.org/TR/xqueryx/, especially Appendix B.

Michael Kay
http://www.saxonica.com/
Author, XSLT Programmer's Reference and XPath 2.0 Programmer's Reference

Thanks for your suggestions regarding XQueryX.

I spent some time reverse engineering the XQueryX translator to look for ideas. The organization of its XSLT translator suggested that I should re-structure my own translator. Unfortunately, XQueryX's simple syntax has been constructed to avoid limitations in XSLT V1.0.

I have posted another topic regarding one of several XSLT V1.0 issues: parsing and translating attribute strings (and their tokens).

Regards,

Philibuster