Does Ruby have something like Python's list comprehensions?
programming-languages, python, ruby
Solution
The common way in Ruby is to properly combine Enumerable and Array methods to achieve the same:
digits.product(chars).select{ |d, ch| d >= 2 && ch == 'a' }.map(&:join)
This is only 4 or so characters longer than the list comprehension and just as expressive (IMHO of course, but since list comprehensions are just a special application of the list monad, one could argue that it's probably possible to adequately rebuild that using Ruby's collection methods), while not needing any special syntax.
Problem
Python has a nice feature: ``` print([j**2 for j in [2, 3, 4, 5]]) # => [4, 9, 16, 25] ``` In Ruby it's even simpler: ``` puts [2, 3, 4, 5].map{|j| j**2} ``` but if it's about nested loops Python looks more convenient. In Python we can do this: ``` digits = [1, 2, 3] chars = ['a', 'b', 'c'] print([str(d)+ch for d in digits for ch in chars if d >= 2 if ch == 'a']) # => ['2a', '3a'] ``` The equivalent in Ruby is: ``` digits = [1, 2, 3] chars = ['a', 'b', 'c'] list = [] digits.each do |d| chars.each do |ch| list.push d.to_s << ch if d >= 2 && ch == 'a' end end puts list ``` Does Ruby have something similar?