What you’re describing isn’t exactly new territory for me. Maybe you’re writing for the room, and not immediately for my benefit. Parsing is kind of… everywher

What you’re describing isn’t exactly new territory for me. Maybe you’re writing for the room, and not immediately for my benefit. Parsing is kind of… everywhere. Path piece instances? Parsing. Forms? Parsing. The whole point of smart constructors is parsing. Deserialising from the persistence layer? Parsing. Sure, JSON and Protobuf also, but even when relying on a robust library like aeson, we still write tests. Why wouldn’t you? The types you define can be serialised in different ways, and the way you deserialise needs to roundtrip with the way you (or an external system) serialise(s), which also necessitates more tests.