The expression tree we're passed represents nested application of map and flatMap.
That power comes with a hard constraint. A Zig error is not a struct or pointer: it is a globally unique, 16-bit integer. The compiler maps every error.FileNotFound across your codebase and every library you depend on to the same integer ID. Zero overhead, zero heap allocations.，这一点在体育直播中也有详细论述
。哔哩哔哩对此有专业解读
Elaboration Zoo, some dependent type systems
Фонбет Чемпионат КХЛ。关于这个话题，PDF资料提供了深入分析