dice-sld.scala

val orig = xml.XML.load("OSM_Roads.sld")

val ftypes = orig \\ "FeatureTypeStyle"

val printer = new xml.PrettyPrinter(80, 2)

for (name <- Seq("railway", "aeroway", "highway")) {
  val nodes = 
    <StyledLayerDescriptor xmlns="http://www.opengis.net/sld" xmlns:ogc="http://www.opengis.net/ogc" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.0.0" xsi:schemaLocation="http://www.opengis.net/sld StyledLayerDescriptor.xsd">
      <UserStyle>
        <FeatureTypeStyle>
          { ftypes.filter { _ \\ "Filter" \\ "PropertyName" forall(_.text == name) } flatMap (_ \\ "Rule") }
        </FeatureTypeStyle>
      </UserStyle>
    </StyledLayerDescriptor>

  val writer = new java.io.FileWriter(name + "s.sld")
  writer.write(printer.format(nodes))
  writer.close()
}