elm/exercises/nucleotide-count/NucleotideCount.example

module NucleotideCount exposing (..)

import String


version : Int
version =
  2


type alias NucleotideCounts =
  { a : Int
  , t : Int
  , c : Int
  , g : Int
  }


init : NucleotideCounts
init =
  { a = 0
  , t = 0
  , c = 0
  , g = 0
  }


update : Char -> NucleotideCounts -> NucleotideCounts
update char counts =
  case char of
    'A' ->
      { counts | a = counts.a + 1 }

    'T' ->
      { counts | t = counts.t + 1 }

    'C' ->
      { counts | c = counts.c + 1 }

    'G' ->
      { counts | g = counts.g + 1 }

    _ ->
      counts


nucleotideCounts : String -> NucleotideCounts
nucleotideCounts sequence =
  String.foldl update init sequence