The list comprehension in your example is now type-stable without additional type-annotation so you can just write [x^2 for x in xs] and the compiler known that

The list comprehension in your example is now type-stable without additional type-annotation so you can just write [x^2 for x in xs] and the compiler known that the results is a list of integers (for your example). There have been many improvements of this type in julia over the years (kudos to all who made this happen).