I know logically there can be only one main entry in a program. But I have a git repository where I want to create different examples of Swift code, and to be able to run each example separately, thus the need for more main entries.
Any ideas as to how I could proceed?
It's a bit different depending if you're using native SPM, or Xcode projects.
In both cases, you'll need to create multiple targets. Each target produces a separate executable, each of which will have one entry point.
The distinction comes in how you share the non-@main related code.
In SPM you would create a library with all the shared code, and make that library a dependency of all of your executable targets.
In Xcode, you can make describe target membership on a per-file level. This is usually pretty tedious and annoying, but in this case it means that each target can contain every file, except for the files that define the other @main entry points.
You might want to check out “Swift Snippets”. This is an upcoming feature of the Swift Package Manager that is available in nightly toolchain builds.
Your code shouldn't have a main entry point. Create a library with public functions. Then, a user can depend on the library and choose which function to run.
See Argument Parser for an example on providing multiple different example targets in a Swift Package Manager project.