As presented, this one is quite dangerous because it's easy to miss the variable assignment. File.read('data.txt') .split("\n") .map { |ln| some_proc

As presented, this one is quite dangerous because it's easy to miss the variable assignment. File.read('data.txt') .split("\n") .map { |ln| some_processing(ln) } .select { |ln| some_filter(ln) } .and_so_on => result I never knew this type of assignment was possible in Ruby, but I will use it if the => var can follow on the next line. A quick test (in 3.1) suggests that it only works with an explicit line continuation: File.read('data.txt') .split("\n") \ => result ...which makes it less appealing. I'll have to try it for a bit to see if I prefer it over the normal `result =` assignment syntax.