Pattern matching about seq HOT 2 CLOSED

fun hash(s: Seq) -> Int {
  match s {
    case `A...`: return 0 + 4*hash(s[1:])
    case `C...`: return 1 + 4*hash(s[1:])
    case `G...`: return 2 + 4*hash(s[1:])
    case `T...`: return 3 + 4*hash(s[1:])
    case ``: return 0
  }
}

source args[0] as input {
  let s = input[:5]
  s |> print
  hash(s) |> print
}

GTGCA
110
TATAT
819
CCTGC
437
TCAAT
775

fun has_N(s: Seq) -> Bool {
  match s {
    case ``: return false
    case `N...`: return true
    case `_...`: return has_n(s[1:])
  }
}