"Useless syntax sugar": Numbered block parameters in Ruby
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"Useless syntax sugar": Numbered block parameters
https://zverok.space/blog/2023-10-11-syntax-sugar1-numeric-block-args.html
Are they as ugly as I was told?
https://zverok.space/blog/2023-10-11-syntax-sugar1-numeric-block-args.html
Are they as ugly as I was told?
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.
I never looked at Ruby, but that doesn't seem like it would be great for readability (although maybe productivity).
People mostly refrain from using it.
Much like people used to create an idiom in Perl and stick to it.
And lets you easily write metal languages due to the way you can pass around blocks. Think configuration as code type stuff.
The liberty to not name things that are obvious.
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.
This makes me want to write a function for you to add to numbers where the variables are leftumber and rightnumber, instead of x and y.
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™.
Well, that's to be expected - the implementation of map expects a function that takes ownership of its inputs, so you get a type mismatch.
If you really want to golf things, you can tack your own map_ref (and friends) onto the Iterator trait. It's not very useful - the output can't reference the input - but it's possible!
I imagine you could possibly extend this to a combinator that returns a tuple of (Input, ref_map'd output) to get around that limitation, although I can't think of any cases where that would actually be useful.
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)
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 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.