Payment Case with FP

Payment.re

type checkNumber = int;

type cardNumber = string;

type cardType =
  | Visa
  | Mastercard;

type creditCardInfo = (cardNumber, cardType);

type paymentMethod =
  | Cash
  | Check(checkNumber)
  | Card(creditCardInfo);

let cardTypeToString =
  fun
  | Visa => "Visa"
  | Mastercard => "Mastercard";

let payme =
  fun
  | Cash => "Pay with Cash"
  | Check(checkNumber) =>
    "Pay with check number: " ++ checkNumber->string_of_int
  | Card((cardNumber, cardType)) =>
    "Pay with a card "
    ++ cardType->cardTypeToString
    ++ " and number "
    ++ cardNumber;

// Bayar utang kamu kisanak!!!
Check(12388234)->payme;