[speed_spread]

It's not magic in how it works, it's just magic in it's syntax. It's a variable you don't have to declare. It's ripe for abuse / mistakes and would be one of the things I'd have lints for and watch closely in PRs.

[cardanome]

Nim has the same result variable[1] and I absolutely love it.

It helps avoid the classic "oh, I forgot to return it" bug. Also makes the code more succinct and saves you from having to type an extra line for explicit return.

I kind of get why you would be wary of it, as it is a special variable but compared to other messed up stuff like for example Rust treating a line without semicolon as implicit return, it is a relatively tame solution for this problem and can be easily figured out.

Did you ever had any actual bugs caused by the use of result?

[1] https://nim-by-example.github.io/variables/result/

[ZoomZoomZoom]

If you forgot to return a value, a function shouldn't have compiled. In Nim you can easily forget to return something or have a hole in your branching and get a defaulted value, instead of a compiler error.

In some cases an implicitly declared variable feels neat and convenient, but I'm not sure it's worth it.

[speed_spread]

Ha, I'm quite used to Rust's last-expression-is-the-value and I also get why some would think it's weird but I find it actually works quite well in practice. Each language has its gymnastics and special moves, I guess. Back to Pascal, I'm not opposed to Result usage per se and I understand the appeal since it's what I grew on. My concerns are more about code maintenance in long-ish functions - I don't have a particular example of mis-usage, but I'd be wary of late reassignments overriding a previously set value. Separating exit points from return value assignment could let code become hard to follow and create situations where it's easy to misread the actual outcome.