1. Start by writing programs with vectors and maps.
2. Learn all about data structures, algorithms, cache misses, memory efficiency etc
3. And then write programs with vectors and maps.
But the maps this time are absl::flat_hash_map (or another C++ alternative hash map such as Folly F14, etc) instead of std::map (or even std::unordered_map).
1. Start by doing everything in ReaderT Env IO
2. Learn all about mtl (or monad transformers, free monads, freer monads, algebraic effects, whatever)
3. Do everything in ReaderT Env IO
But the maps this time are absl::flat_hash_map (or another C++ alternative hash map such as Folly F14, etc) instead of std::map (or even std::unordered_map).