I’ve done this at times in Python and C#, I really really miss Go or - better - Rust style errors there. But, exactly like you say, you end up fighting librari

I’ve done this at times in Python and C#, I really really miss Go or - better - Rust style errors there. But, exactly like you say, you end up fighting libraries - particularly the standard libraries, and it ain’t a fight you will win. In typescript it actually kind of works - better at least. JS APIs often are errors-as-values already because of the old continuation async APIs, and typescript of course lends itself incredibly well to rich return types.