and that's yet another way to end up with hard to read code.
Variables hold values that have meaning. Learn how to name things and you'll write good code.
edit: someone just wrote an article along these lines. The only thing I'd change is the cause-effect relationship between bad names and bad code. IME bad names lead to bad code, not usually the other way around. The reason is that by starting from good name choices, it's much easier to have a well structured code. And not rarely, bad names lead to mangled up code that screams for a refactoring.
That deserves an "always has been" meme... But IMO, Ruby outperled Perl since the beginning.
Perl doesn't let you redefine the syntax so that you can write the same program multiple ways. All it does is to encourage multiple programs to have the same meaning.
Ruby cribbed a whole lot of syntax from Perl from the very beginning. Most of the rest comes from Smalltalk, but Ruby got it's multitude of two character "$" variables from Perl, it's autosplit mode (-a -n -p switches, letting Ruby, like Perl "emulate Awk"), it's regexp match captures going into $1, $2 etc. from Perl.
tbf positional arguments are already bad enough. Now if you're using over 9 positional args... just take a break, go for a short walk, and maybe you'll come back with a better plan
I mean 4 is probably too many, 8 definitely is, but also what about splat-args like zip or min. Why not stop at 4? Why not stop at 8 since its a power of two? Any hand-picked limit just feels pretty bleh to me. Either support everything or dont support it at all IMO
It wouldn't be as relevant, since passing a function or method instead of a closure is much easier in Rust - you can just name it, while Ruby requires you to use the method method.
So instead of .map(|res| res.unwrap()) you can do .map(Result::unwrap) and it'll Just Work™.
In the case of your example we'd do .map(&:unwrap) in Ruby (if unwrap was a method we'd actually want to call)
Notably, these are not the cases _1 and _2 etc are for. They are there for the cases that are not structurally "call this method on the single argument to the block" e.g. .map{ _1 + _2 } or .map { x.foo(_1) }
(_1 is reasonable, because iterating over an enumerable sequence makes it obvious what it is; _1 and _2 combined is often reasonable, because e.g. if we iterate over a key, value enumerable, such as what you get from enumerating a Hash, it's obvious what you get; if you find yourself using _3 or above, you're turning to the dark side and should rethink your entire life)
I do think the unnumbered variant of such anonymous parameters is useful, if you've got a team of devs that knows not to misuse them.
In particular, folks who are unexperienced will gladly make massive multi-line transformations, all in one step, and then continue blathering on about it or similar, as if everyone knew what they were talking about and there was no potential for ambiguity.
This is also particularly annoying, because you rarely read code top-to-bottom. Ideally, you should be able to jump into the middle of any code and start reading, without having to figure out what the regional abbreviations or it mean.