[j-james]

> You can also not really have productive and well-fitting errors-as-values in a language that emphasizes UFCS

Eh, https://github.com/arnetheduck/nim-results and associated syntax from https://github.com/codex-storage/questionable would beg to disagree. Nim's stdlib does not have productive and well-fitting errors because it suffers from inertia and started far before the robust wonders of recoverable error handling via errors-as-types entered the mainstream with Rust and were refined with Swift (IMO). Option/Result types are fantastic and I do so wish the standard library used them: but it's nothing a (very large) wrapper couldn't provide, I suppose.

I do strongly think that other languages are greatly missing out on UFCS and I miss it dearly whenever I go to write Python or anything else. I'm not quite sure how you think UFCS would make it impossible to have good error handling? Rust also has (limited, unfortunately) UFCS and syntax around error handling does not suffer because of it. If by errors-as-values you mean Go-style error handling, I quite despise it - I think any benefits of the approach are far offset by the verbosity, quite similarly to Java's checked exceptions.

(in general concerns surrounding performance of errors surprise me - they're errors! they shouldn't be hit often! but if they are, you can certainly avoid such performance hits in nim.)