Ruby Coding Style

 1l = [1, 2, 3]
 2
 3l.each do |n| n += 1 end
 4
 5l.map { |n|
 6  b = (n + 1) * (n + 2) / 3.0
 7  b.to_s
 8}
 9
10identity = ->(x) { x }
11say = ->(x) do puts x end

1mod M
2  def self.a; 'a'; end
3  def self.b; 'b'; end
4  # more ...
5end
6
7M.a()

 1module M
 2  # module_function will copy the functions. No need to make duplicated
 3  # functions unless you want to let other classes include your module
 4  # and let them pollute other classes' namespcae.
 5  module_function
 6
 7  def a; 'a'; end
 8  def b; 'b'; end
 9  # more ...
10end
11
12M.a()

 1class C
 2  # Do not build a class just for some functions. Use module for this.
 3  class << self
 4
 5    def a; 'a'; end
 6    def b; 'b'; end
 7    # more ...
 8  end
 9end
10
11C.a()

1class C
2  def a; 'a'; end
3  def b; 'b'; end
4  # more ...
5end
6
7# This is redundant.
8c = C.new()
9c.a()