[chrislattner]

Mojo has overloading, generics and a much more advanced type system than Swift (dependent and linear types etc), and compile time in all phases is very important. The Mojo design seems to be working well - it gives expressive power, good error messages etc.

It feels like a much better design point overall.

[slavapestov]

I wasn’t trying to start a fight over languages, that would be silly. I also wrote a language once and then moved on from it (to your former language ;-)), so I know the feeling! I wish you luck with your new language, and I wish for many more languages in the future to try different approaches and learn from each other.

My original reply was just to point out that constraint solving, in the abstract, can be a very effective and elegant approach to these problems. There’s always a tradeoff, and it all depends on the combination of other features that go along with it. For example, without bidirectional inference, certain patterns involving closures become more awkward to express. You can have that, without overloading, and it doesn’t lead to intractability.

[chrislattner]

Sure, I wasn't trying to start a fight either, I was just sharing my experience and opinion on having worked on both. Mojo (and C++) have closures, for example c++ does lambda type inference without a constraint solver.

In my opinion, constraint solving would be a bad design point for Mojo, and I regret Swift using it. I'm not trying to say that constraint solving is bad for all languages and use-cases.