Multiple types like in TypeScript

[al3c]

Has been discussed profusely here:

Union types

another great thing: you could use it in combination with a bigger abstraction of ?. do do great things like allow for specifying on which concrete type a call-chain should continue / allow for call-chains to continue regardless of the concrete type. Say we would be using unions to implement a result-type (i know, this isn’t the best example, as a Result type is easy to implement with sealed-classes, its just an easy-to-understand example say you have val value: [ Int, String ] = 12 // scope…

For what’s it worth, I really like the ? since something|null is where this is really useful