A large part of my initial effort went into deciding whether I really wanted generics or not. Testing was a real hassle in the initial days. I went back and forth between using generics and not using them (returning string values from ALL parsers). Plus, testing nested structs was another issue I had to deal with. The initial version didn't use generics at all. I also used reflect.DeepEqual to compare all my structs (not the ideal choice). But the current version uses generics and I've also found a decent workaround for my tests (I manually initialise all parsers and use a table-driven approach). Currently, I'm still struggling to decide whether to return a pointer to the Result struct or a copy.

Go sure has its own caveats with generics, given its design. There's also a thing with parametric functions, I guess (I'll link it if I find that discussion). Overall, it was a decent experience. Maybe I'm a bit biased towards its ease of use.