Command line swift

It is perhaps quixotic (unrealistic or impractical), but I like doing things without Xcode sometimes. Xcode is a complicated beast. So in testing code I've been doing

swift test.swift

from the command line, updated from

xcrun swift test.swift

which I used to do.

I was excited to find that it is possible to use code in more than one Swift file, like this:

swiftc file1.swift main.swift -o prog
./prog


Credit:
http://stackoverflow.com/questions/29089861/how-to-import-modules-without-an-xcode-project-in-swift


Reading the man page for swift and swiftc I find these ideas:

swiftc -emit-library card.swift

which runs and gives libcard.dylib but I have no idea how to import it from Swift.

There is also -emit-module, which gives card.swiftdoc and card.swiftmodule but I have no idea how to use them.

Maybe I should look inside Xcode and try to figure out how it accomplishes what it does?