> Java streams is that they're as powerful as Ruby's functional-style operation chaining (arr.map{}.reduce(:+) etc) This is not a unique Ruby feature though. I

> Java streams is that they're as powerful as Ruby's functional-style operation chaining (arr.map{}.reduce(:+) etc) This is not a unique Ruby feature though. Iterators are very common nowadays. Java streams have okay performance, much like .NET's LINQ you likely won't be able to use them in a really performance-sensitive code (although LINQ is improving quite a bit with each new release, overall it performs moderately to significantly faster than Java Streams, but usually slower than Rust iterators).