Safe null access

Smart casts are a very nice feature, and offer a readable way to do branching when dealing with nulls. However, when we have chained operations, and each step may produce a null, the code quickly becomes unreadable.

Consider the following snippet:

    class Person(name: String, val address: Address?) 
    class Address(name: String, postcode: String, val city: City?) 
    class City(name: String, val country: Country?) 
    class Country(val name: String) 
 
    fun getCountryName(person: Person?): String? { 
      var countryName: String? = null 
      if (person != null) { 
        val address = person.address 
        if (address != null) { 
          val city = address.city 
          if (city != null) { 
            val country = city.country 
            if (country != null) { 
              countryName = country.name 
            } 
          } 
        } 
      } 
      return...