I’ve just finished generics with type parameters, no surprise since I already implemented symbol generics. So far Skila does not have constraints, but I prefer to cover more ground in order to have working language in hand. Collections (and passing them around) is my next step.
Since this will take some time, I might make a break and add static virtual methods. You can say — “what? How a static method can be virtual”. Well, in C++/C# it cannot, because it was implemented that way. All it takes is one look from different perspective — take a regular virtual method and limit its access to static features only. Here you have it — static virtual method.
It is not a feature I will die for, but I too often bump into a problem which could be nicely solved having static virtual method and its cousin — pinned method (new concept), static or not. Pinned method is just like virtual one but it is erased with each new class in hierarchy, meaning once you add it somewhere you have to redefine it in each descendant class. This is pretty similar to pinned constructors (which are already implemented in Skila).
With such arsenal you can finally decide what is better for you, static factories or per instance, you can handle some traits of the class (type) with static methods. Nothing revolutionary, just more freedom and flexibility.
And since there is already so much variety why not add yet another one, with even more limited access — actually with no access at all. Function/method which relies only on its parameters with no side effects, pure function. We’ll see…