RBS, Ruby’s new type signature language

I'm not thrilled about the separate files with the type information but I completely understand why they did it, and if it were my choice I might make the same one.

I don't like the comparison with TypeScript `.d.ts` files however, because TS still lets you do types inline in the code. I haven't seen it mentioned anywhere that this won't be supported by Ruby 3.

Does anybody know if Ruby 3 will also support inline type information or will the header RBS files be required?

I much prefer separate files for type declarations. Or at least the ability to define them separately. Type annotation takes away from readability. I like keeping the types and code separate.

Type annotations aren't inline in all languages. If you're writing Haskell or Elm, as a few examples, then you get static types without having to write them out and if you do write them out they sit above the function that uses them.