Programming Crystal

Mixing in Modules

Modules group methods, and then you can use their functionality in different classes. To do that, the module’s code is mixed-in to other types, as in Ruby or Dart. You do this with the keyword include. When a class does an include ModuleName, its objects can use the methods of the included module as their own methods! You saw an example in ​Organizing Code in Classes and Modules​.

Here’s another example: Both classes DVD and BlueRay include the module Debug, so objects made of these classes can use its method who_am_i?

working_with_modules/mixins.cr

class Basic
  def initialize(@name : String)
  end

  def to_s
    @name
  end
end

module Debug
  def who_am_i?
    "#{self.class.name} (