alt Hacker NewsSorry for the non constructive comment:
I wish we would stop xxx::yyy::zzz for namespace.
It was horrible in C++ from day one, and is still horrible in Rust.
It had some reason to be this way in C++ but not in any other newer language.
Real negative part: it looks to me that the authors of those languages are parroting other languages rather than understanding the reason of those language choice.
This simply worries me because I judge the level of expertise and makes me not consider the language in the first place.
(I know C++ and Rust are alive but they share their fair share of poor design choice)
Replies
> It was horrible in C++ from day one, and is still horrible in Rust.
I don't get it. Is it syntactically horrible or are there real reasons that I'm missing?
My favorite namespacing syntax is ironically Clojures. module/func or fully.qualified.module/func or just func if you explicitly import the symbol. I vastly prefer shallow namespacing (module/func) most of the time.
I write Rust mostly for my day job (and it's also my preferred language on the side these days), so I usually end up explicitly importing all the symbols I actually use because module::func is just additional noise in an already pretty verbose language and is what's considered 'idiomatic'.
I don't really get the issue with :: being the separator used here. It's slightly ugly, but it's visually distinct from . for field access, which I do appreciate.
> it looks to me that the authors of those languages are parroting other languages rather than understanding the reason of those language choice.
I don't mean this to sound combative, but I think you are the one who doesn't understand the reason for the language choice. I assume you're objecting to the fact that these languages use different operators for module/namespace paths (`::`) and object member/method access (`.`), not the `::` symbol specifically.
You seem to assume that Rust blindly imitated C++, but that's not the case. The `::` syntax allows the compiler to identify and resolve all the static paths before any type inference or other analysis. This is important because macros are expanded between these stages, and can in turn introduce more static names which must also be resolved before any further compilation.
You might be able to introduce a rule that any `.`-path that can be resolved statically will be, trumping any non-static members (or maybe not, it might cause ambiguities I'm not thinking of), but Rust's stated design philosophy favors explicitness.
I don't know what this language's reason for using it was, as I don't see any mention of macros. But in general it simplifies compiler design. If you can resolve all the static names up front, the following compiler stages can ignore the concept of namespaces altogether.