http://code.google.com/p/syntaxhighlighter/
object Timer { def oncePerSecond(callback: () => unit) { while (true) { callback(); Thread sleep 1000 } } def timeFlies() { println("time flies like an arrow...") } def main(args: Array[String]) { val exp: Tree = Sum(Sum(Var("x"),Var("x")),Sum(Const(7),Var("y"))) val env: Environment = { case "x" => 5 case "y" => 7 } println("Expression: " + exp) println("Evaluation with x=5, y=7: " + eval(exp, env)) println("Derivative relative to x:\n " + derive(exp, "x")) } }