Why can’t I use `suspend fun foo(): T` instead of ...

# javascript

[Marc Knaup]

Why can’t I use suspend fun foo(): T instead of fun foo(): Promise<T> in an external interface?

[jw]

Because they don't work the same way. Suspend functions receive a continuation and return synchronously when suspended. A promise is an encapsulation of running work like a Future.

[turansky]

Why can’t I use

You can 🙂

[turansky]

Compiler plugin can do this as I understand

[turansky]

But I see problem in such “magic” - ordinal classes can implement external interfaces.

[Marc Knaup]

@jw thanks, that explains what I see. I was surprised that my suspend funs were returning Promises :)