yeah, Erlang-wise, most loggers have done these checks for years. There's always a big concern in terms of avoiding the most work possible as early as possible so all that filtering takes place early on.

The handler and filter structure with both global and per-handler filters is fairly clever as a way to turn these things on and off easily, and the module and level checks are done the earliest since they can allow to eliminate the most amounts of logs the cheapest way possible.