Another exercise, perhaps less demanding in this regard, is to explore using Free Monads[0] to implement an EDSL[1] for a problem domain. Of course, the approachability of this varies based on the person involved.

> For instance, and amusingly enough written in golang, one of the most respected recent books on this topic is `Writing an Interpreter in Go` and its sequel `Writing a Compiler in Go`.

Queue obligatory reference to "the dragon book":

  Compilers: Principles, Techniques, and Tools[2]

1 - https://www.quora.com/What-is-an-embedded-domain-specific-la...

2 - https://suif.stanford.edu/dragonbook/