for rosalind

dna.scala

package hemplant.rosalind.dna

sealed abstract trait Nucleotide{
  def complementary:Nucleotide = Nucleotide.complementary(this)
}
case object A extends Nucleotide
case object T extends Nucleotide
case object G extends Nucleotide
case object C extends Nucleotide

object Nucleotide{
  def apply:Char => Nucleotide = {
    case 'A' => A
    case 'T' => T
    case 'G' => G
    case 'C' => C
  }

  def complementary:Nucleotide => Nucleotide = {
    case A => T
    case G => C
    case C => G
    case T => A
  }
}