[alexashka]

Just wanted to say that module maps are absolutely not necessary to have static libraries (.a file author compiles his go program to) in your project.

All you need is an objective-c bridging header where you do an #import "name_of_header_.h" for every header. After that, the headers are visible to all of your swift code. It's no different than mixing objective-c and swift, except here you're mixing your language of choice, compiled to callable C functions inside a static library.

To recap - drag .h and .a files the same way you have .swift files into your xcode project. Add a BridgingHeader.h file, go to it, fill it with #import "name_of_header.h" statements. Lastly, the project needs to know you're using a bridging header, that's done in the project target's Build Settings tab, under "Objective-C Bridging Header" you need to have the value set to the filename you chose for your bridging header.

This is not unique to calling Go in Swift btw - any language that can be called from C, can be called from Objective-C, and therefore Swift. One thing to be aware of is memory management - unless you're passing things by value (copying), making sense of when things can be safely deallocated across languages is non-trivial.