Power of switch statement in groovy

Very impressive (and expressive):

def x = 'test'

switch(x) {
  case null:
    println 'null!'
    break
  case ~/(?i)Test/:
    println 'got it!'
    break
  default:
    println 'something else'
}

here second 'case' does case-insensitive regex comparison. In general, case may contain any regex, collection, range or class.