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Comment by kaba0 | Hacker News Reader

I think Scala is hands down the best collections/stream library, I especially like their _ shorthands:

  val num = words.count(!_.isEmpty())

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Understanding bird droppings like “!_.()” relies on quite some prerequisites.

! contradicts a boolean. _.isEmpty() is a lambda, applying the isEmpty function on its string parameter. It’s just the two things together.

I know all this. But as I said, pulling it all together involves quite a number of concepts represented by idiosyncratic punctuation, much more than “count all non-empty elements”.

Then your team can write lambdas in a more verbose, but less cryptic style.

When I was introducing a team to Scala I wrote everything in a more verbose style just to make it clear, e.g.

  val num = words.count(word => word.nonEmpty)

The "bird droppings" (particularly the clever uses of _ found across Scala) were hard for me to grasp when I first started working in the language. Now they're second nature, but I try to remain cognizant of future maintainers who may be coming in to make contributions or bug fixes without first marinating in the language.

The nice thing is you can just write it like `x => !x.isEmpty` if you want

Or more succinctly

  val num = words.count(_.nonEmpty)

I think that is a horrifying crime against man and nature. If I wanted to write PERL I would do so.

What is hard to understand about it? _ is universally used as a placeholder, it also usable in pattern matching. Scala can be used to make some perl-y <!! operators, but it is not like that at all, and makes for very readable, understandable code.

Also targeted at Java 22: https://openjdk.org/jeps/456 (Unnamed Variables & Patterns)

Same, I wish more languages had that shorthand

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