6 ms·

I'm not following your answer to 2, do you have an example?

• ohgodplsno 6y ago
  Say you'd like to have a foo method that returns... a number, whatever. You do not need to have multiple symbols "fooString", "fooDecimal", "fooString", etc. Simply overloading the parameters gives you type safety, and keeps a single foo symbol. fun foo(value: String): Int = value.length() fun foo(value: Int) = value fun foo(value: RemoteDatabase) = value.servers.map { it.connect().executeSql("SELECT 1")[0].toInt() }.sum() All these define a foo method, that returns an Int. The untyped alternative (what javascript, python, etc do in a naive way, without trying to duck type) is to do this: fun foo(value: Any) = when (value) { is Int -> value is String -> value.length() is RemoteDatabase -> value.servers.map { ... }.sum() else -> error("Welp, our type system couldn't help us there.") } Additionally, if it really makes sense, you can define foo as an extension function on the type: fun Int.foo() = this fun String.foo() = length() fun RemoteDatabase.foo() = servers.map { ... }.sum() You can then use it directly on the type, rather than call foo(1): val fooResult = 1.foo() val fooStringResult = "Well hello there".foo()