Does Crystal have something like Intersection Types ? 
I'm a bit confused, because I think unions behave differently 
Maybe it's not valid to compare Flow & Crystal :sweat_smile:
can someone help explain the usage of
funoutside of a
libdeclaration to me?
I think the
fun usage outside libs is very limited,
fun doesn't support overloading and only support basic types, I think it is more like a C function, thinking on shared libraries or similar stuff.