Pattern matching is definitely something I also miss. For input validation and Optional/Either types, io-ts/fp-ts (https://github.com/gcanti/io-ts https://githu

Pattern matching is definitely something I also miss. For input validation and Optional/Either types, io-ts/fp-ts (https://github.com/gcanti/io-ts https://github.com/gcanti/io-ts) fulfill my needs perfectly, especially io-ts is something I can't recommend enough. Saved me so many headaches from sudden breaking changes in APIs we consume.