Where are callable classes useful?

Question

Dart

Who can explain in what situations callable-classes are useful ? Why is this better than calling methods?

Answer 1

You write a class.
It has a lot of internal logic, mb parsers.
It can contain streams, etc.
Normal reference to an instance is like a class.
But if you need to call it as a function, this is where it comes in handy.
A very contrived example:

class Counter {
    int _count = 0;
    call() => _count++;
}
var counter = Counter();
Button(onTap: counter)

You can get by with the method.
This is necessary for the convenience of solving problems, like almost everything in any programming language.