Curious as to why `Number` is a class as opposed t...

# language-evolution

[natario1]

Curious as to why Number is a class as opposed to an interface, any hints?

[Ilmir Usmanov [JB]]

Java interoperability - https://docs.oracle.com/javase/8/docs/api/java/lang/Number.html

[natario1]

I see, thanks! Annoying legacy though. Hit this issue while trying to

inline class Amount(val specialNumberNotation: String) : Number { ... }

[Ky Leggiero]

I really wish they could've improved this. Maybe a interface Numerical that Number conforms to. Hopefully that'll happen someday; I really love using that kinda stuff in Swift

[elect]

is should be definitely be an interface to allow unsigned to extend that as well

[Hullaballoonatic]

not to mention an abstract class that has purely abstract members offers nothing of benefit over an interface

[louiscad]

class MyData : CharSequence, List<Int>, Number() {
    ...
}