Custom string interpolation

customsi.scala

object Test {

  // Implicit class is also a new feature in scala 2.10
  implicit class CounterSC(val sc: StringContext) extends AnyVal {
    // Define functions that we want to use with string interpolation syntax
    def partsCount(args: Any*): Int = sc.parts.length
    def argsCount(args: Any*): Int = args.length
    def tokenCount(args: Any*): Int = sc.parts.length + args.length

    def getParts(args: Any*): String =
      s"parts: ${sc.parts.mkString(",")}"

    def getArgs(args: Any*): String =
      s"args: ${args.mkString(",")}"
  }

  def main(args: Array[String]) {

    val value = "value"
    val num = 3
    // Use the functions that we created when the implicit class is in scope
    val i = tokenCount"Scala $num interpolation ${1 + 1} lastarg $value"
    val p = partsCount"Scala $num interpolation ${1 + 1} lastarg $value"
    val a = argsCount"Scala $num interpolation ${1 + 1} lastarg $value"
    val parts = getParts"Scala $num interpolation ${1 + 1} lastarg $value"
    val arg = getArgs"Scala $num interpolation ${1 + 1} lastarg $value"

    println(s"token count: $i") // token count: 7
    println(s"args count: $a")  // args count: 3
    println(arg)                // args: 3,2,value
    println(s"parts count: $p") // parts count: 4
    println(parts)              // parts: Scala , interpolation , lastarg ,
  }
}