The Pearls of Functional Algorithm Design is like the On Lisp of Haskell. It's a stunning, challenging intermediate FP programming book that focuses on how equa

The Pearls of Functional Algorithm Design is like the On Lisp of Haskell. It's a stunning, challenging intermediate FP programming book that focuses on how equational reasoning allows you to "automatically" move from unoptimized, unelegant, fragile code to optimal, beautiful code correctly. I cannot recommend it enough.