List comprehension in Ruby

Question

To do the equivalent of Python list comprehensions, I\'m doing the following:

some_array.select{|x| x % 2 == 0 }.collect{|x| x * 3}

Is ther

Answer 1

I've just published the comprehend gem to RubyGems, which lets you do this:

require 'comprehend'

some_array.comprehend{ |x| x * 3 if x % 2 == 0 }

It's written in C; the array is only traversed once.