Code snippets for the `value-based classes and error-handling` Medium article.

value-based-adt-list-example.kt

data class Password private constructor(val value: String) {
  companion object {
    fun of(value: String): Either<List<Violation>, Password> {
      val violations = buildList {
        if (value.isTooShort()) { add(Violation.PasswordTooShort(MIN_LENGTH)) }
        if (value.containsNoNumbers()) { add(Violation.PasswordContainsNoNumbers) }
      }
      return if (violations.isEmpty()) Password(value).right() else violations.left()
    }
  }
	
  sealed class Violation {
    data class PasswordTooShort(val minLength: Int) : Violation()
    object PasswordContainsNoNumbers : Violation()
  }
}