I think the right model for compile-time evaluation is to have an interpreter and phases, making the full language available at compile-time but clearly disting

I think the right model for compile-time evaluation is to have an interpreter and phases, making the full language available at compile-time but clearly distinguishing between compile-time, macro-expansion, module elaboration and runtime phases. Scheme dialects generally do that, although they should maybe define module visiting and elaboration orders in general more clearly like e.g. Ada does. I don't know if Zig does that. Anyway, having different phases is not conceptually hard, although it can bite you a bit with Macros in Scheme.