Further up he discusses that using a functional paradigm is possible, but concludes that it doesn’t feel like a practical choice because of how Zig does memory management:

> But the language quickly forces you to diverge from the functional style, mostly because you’re now dealing with allocators directly, and a genuinely pure functional approach means constantly constructing new structures. That’s either expensive in memory or expensive in the manual bookkeeping needed to avoid it.

So I don’t think he’s trying to say that it’s literally impossible. It felt more like the result of a good faith attempt to understand how Zig itself actually wants to be used, and to compare that to how he’s used to using Rust.

I actually liked that he did it. So many other comparisons want to evaluate one language against the other language’s values. But I don’t want to know how well Zig can do Rust; I want to know how well Zig accomplishes its own goals, and what those goals are.