use memoized attributes instead of process methods

gistfile1.rb

# Memoized facade attribute 
# √ Lazy loaded
# √ Better encapsulated / more 'atomic'.  Processing introduces unnecessary depencies at different times of the life cycle of the object.  
# √ More idiomatic mindset to think of these are 'attributes' on an object, than results of a calculation 

# Memoized attribute
class RecommendationCalculator
  
  attr_reader :user
  
  def initialize(user:)
    @user = user
  end

  def recommendations
    @recommendations ||= (
      # calculate recommendations
    )
  end

end


# Process / Calculate method 
class RecommendationCalculator
  
  attr_reader :user, :calculated_recommendations
  
  def initialize(user:)
    @user = user
    @calculated_recommendations = calculate_recommendations(user: user, location: user.current_location)
  end
  
  
  private
  
  def calculate_recommendations(user:, location:)
    # calcualte recommendations based on user and location
  end

end

There is a "gotcha" when using ||= memoization - specifically memoizing an object that evaluates to false. This doesn't come up often, but can be a difficult to track down.