enigma1.fs

namespace Enigma

open System

type AlphabetMapping = string
type RingSetting = RingSetting of char
type WheelPosition = WheelPosition of char
type KnockOn = WheelPosition list
type PlugBoard = PlugBoard of string list
type Reflector = Reflector of AlphabetMapping
type Rotor =
    {   Mapping : AlphabetMapping
        KnockOns : KnockOn
        RingSetting : RingSetting }
type Enigma = 
    { Left : Rotor * WheelPosition
      Middle : Rotor * WheelPosition
      Right : Rotor * WheelPosition
      Reflector : Reflector
      Plugboard : PlugBoard }
      
// Example usage
let rotor1 =
    {   Mapping = "EKMFLGDQVZNTOWYHXUSPAIBRCJ" // map these to ABCDEF...XYZ
        KnockOns = [ WheelPosition 'E' ] // flip adjecent rotor whenever this one reaches "E"
        RingSetting = RingSetting 'A' } // default ring setting
let reflectorA = Reflector "EJMZALYXVBWFCRQUONTSPIKHGD"
let myEnigma = { Left = rotor1, WheelPosition 'A'
                 Middle = rotor2, WheelPosition 'A'
                 Right = rotor3, WheelPosition 'A'
                 Reflector = reflectorA
                 Plugboard = Plugboard "AB VS DG CL HU FZ KN IM RW OX" }