Generics

[verygoodsoftwarenotvirus]

Hi there! I've been looking at a few embeddable languages in Go and I quite like your project. I was wondering what you think about the use of Generics in the library, and getting rid of the empty Evaluator struct? I've got a branch with the code changes if you'd like to take a gander (I'm not going to bug you with a PR to review).

It breaks having nil be something you can evaluate/return on its own, so I had to delete/exclude some of those tests, and it necessitates a /v2 release of the codebase because it would break backwards compatibility. In exchange for those tradeoffs, though, you get to avoid a lot of the if val, ok := interfaceVar.(string); ok { stuff you might otherwise have to endure

[maja42]

I'd need to take a closer look at a generic approach, but on first glance, I don't think the advantages outweigh the disadvantages.
It would be a breaking change that requires a v2, only for putting the type assertion inside the evaluator itself.
It would also force everyone to update to go1.18+ (which isn't too bad, but still).

[maja42]

I don't plan on breaking compatibility for adding generics.
Unless it adds additional benefits outside saving a type-cast (which could also be done by a simple wrapper), I don't think it is worth the cost.