I don't see how passing in a logger object explicitly is the same, this is what OO DI frameworks try to avoid, otherwise you'd also have to pass it down to othe

I don't see how passing in a logger object explicitly is the same, this is what OO DI frameworks try to avoid, otherwise you'd also have to pass it down to other functions used inside. The example above works just like a Reader Monad, but we are not tied to any specific logging implementation. I guess the side effecting version is just to use some global registry to look up the logging implemention to use. But such code does not compose.