{
  a: in0 match {
    case {k1:v1 ~ tail1} -> k1
    else -> "foo"
  },
  b: in0 match {
    case {k2:v2 ~ tail2} -> v2
    else -> "foo"
  },
  c: in0 match {
    case {k3:v3 ~ tail3} -> tail3
    else -> "foo"
  },
  d: in0 match {
    case {k4:v4 ~ tail4} -> {k4:v4}
    else -> "foo"
  },
  e: in0 match {
    case {k4:v4 ~ tail4} -> {(k4):v4 ~ tail4}
    else -> "foo"
  },
  f: {a: 1 ~ {b:2, c: 3}}
}