idk in elixir we basically do exactly whats happening with io parameters when mocking or swapping implementations that all satisfy the same behaviour.

here. i am not the only one that refers to it as dependency injection:

https://daily.dev/blog/zig-async-io-io-uring-zig-0-16-rethin...

"Zig 0.16 introduces std.Io, a flexible I/O abstraction that uses dependency injection, similar to the Allocator interface"

Sigh. I meant that the zig authors did not make it a general pattern and just slapped on the DI pattern specifically for io, instead of generalising the abstraction so people can DI stuff.