For most intents and purposes one can use a (potentially Singleton) type passed as a argument to functions instead of a module containing functions. And doing t

For most intents and purposes one can use a (potentially Singleton) type passed as a argument to functions instead of a module containing functions. And doing that gets you all the tooling and power you could want. (But probably in a different way to you want it). Since multiple dispatch takes care of that. You can compare and contrast MLDatasets.jl (uses submodule per dataset) vs CorpusLoaders.jl (uses a extra type argument per dataset)