Ой, а ещё какой-то logging-effect есть:
> Unlike other logging libraries available on Hackage,
MonadLog does
not assume that you will be logging text information. Instead, the choice of logging data is up to you. This leads to a highly compositional form of logging, with the able to reinterpret logs into different formats, and avoid throwing information away if your final output is structured (such as logging to a relational database).
Just what I need!