Apparently to use C code in Swift one only needs to import the header files:
> You can access and use pieces of code written in C and Objective-C from > within your Swift code. After you import an Objective-C framework, a C > library, or a header file, you can work with Objective-C classes and > protocols, as well as common C constructs, functions, and patterns. [https://developer.apple.com/documentation/swift/imported_c_and_objective-c_apis](https://developer.apple.com/documentation/swift/imported_c_and_objective-c_apis) So I imagine it's just a matter of translating Nim to C and use the header files in Swift without the need of a framework/library.
