A quick experiment with Scala and Xml

prettyXml.scala

    import scala.xml.{NodeSeq,Text,Elem}
    def prettyXml( prefix: String, nodes: NodeSeq ): String = {
      nodes match {
          case txt : Text => 
            val trimtxt = txt.text.trim 
            if (trimtxt.length > 0) prefix+trimtxt+"\n" else ""
          case elem : Elem => 
            prefix+"<"+elem.label+">\n"+
              prettyXml(prefix+"  ", elem.child)+
              prefix+"</"+elem.label+">\n"
          case nodes : NodeSeq => 
            ("" /: nodes) (_ + prettyXml(prefix, _))
      }
    }
    
    println( prettyXml("", <test>
                             <tag>1</tag>
                             <tag>2<subtag>a</subtag>3</tag>
                             <group>
                               <subgroup>
                                <element>I</element>
                                <rank>A</rank>
                               </subgroup>
                             </group>
                           </test>) )