These allow us to pass behavior to an Option instance that will only execute if it has a value (ie an instance of Some). For example, to get a collection of the status updates:

val matches = new HttpXMLMatches()
val url = “http://twitter.com/statuses/public_timeline.xml”
matches.getXML(url).map { _ \ “status” “text” map { _ text } }

This results in a Some[Seq[String]] of the text nodes of the status updates. You could also use for comprehensions:

for(xml <- matches.getXML(url)) yield (xml \ “status” “text” map { _ text })

Or if you just want to do some side-effecting action, like printing the text:

for(xml <- matches.getXML(url)) { println(xml \ “status” “text” text) }

I'm still trying to work out some guidelines as to when monadic handling is preferable to exceptions.