[swift-evolution] [Pitch] allow define submodule in Foundation or file group like Swift Standard Library?

[Cao Jiannan]

I notice that Swift Standard Library using GroupInfo to define group of swift files. And Xcode can show that group in editor. e.g. Math.

Will Apple allow Swift developer to define group in their own framework? So they can see the special generated type information instead of a long file.

In Foundation, there are submodules inherits from C headers. Will Apple allow Swift developer to define submodule in their own framework?
 e.g. import MyFoundation.Math

Thanks!