How do I parse an xml document as a stream using Scala?

Question

How do I parse an xml document as a stream using Scala? I've used the Stax API in java to accomplish this, but I'd like to know if there is a "scala" way to do this.

Answer 1

scala.xml.XML.loadFile(fileName: String)
scala.xml.XML.load(url: URL)
scala.xml.XML.load(reader: Reader)
scala.xml.XML.load(stream: InputStream)

There are others...

Answer 2

Use package scala.xml.pull. Snippet taken from the Scaladoc for Scala 2.8:

import scala.xml.pull._
import scala.io.Source
object reader {
  val src = Source.fromString("<hello><world/></hello>")
  val er = new XMLEventReader(src)
  def main(args: Array[String]) {
    while (er.hasNext)
      Console.println(er.next)
  }
}

You can call toIterator or toStream on er to get a true Iterator or Stream.

And here's the 2.7 version, which is slightly different. However, testing it seems to indicate it doesn't detect the end of the stream, unlike in Scala 2.8.

import scala.xml.pull._
import scala.io.Source

object reader {
  val src = Source.fromString("<hello><world/></hello>")
  val er = new XMLEventReader().initialize(src)

  def main(args: Array[String]) {
    while (er.hasNext)
      Console.println(er.next)
  }
}