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

Like Pedro mentioned, you can fuse together the chained calls to Enumerable#select and Enumerable#map, avoiding a traversal over the selected elements. This is true because Enumerable#select is a specialization of fold or inject. I posted a hasty introduction to the topic at the Ruby subreddit.

Manually fusing Array transformations can be tedious, so maybe someone could play with Robert Gamble's comprehend implementation to make this select/map pattern prettier.