Function<String, int> in Dart?

Question

I have a function with a callback void doSth(Function callback), however I would like to specify the parameters and return value of the callback like in Java.

Is this possible in Dart?
(I can't use Future here)

Answer 1

void doSth(String Function callback(int /* type for parameter */ ))

See also https://www.dartlang.org/guides/language/effective-dart/design#prefer-inline-function-types-over-typedefs