Module: SuperMemo::SM2

Defined in:
lib/spaced-repetition/sm2.rb

Overview

This module can be used as a mixin to add the algorithms as used by SuperMemo 2 (typically referred to as SM2).

See the README for more information.

Class Method Summary collapse

Instance Method Summary collapse

Class Method Details

.extended(obj) ⇒ Object 



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# File 'lib/spaced-repetition/sm2.rb', line 9

def SM2.extended(obj)
  obj.check_spaced_repetition_methods
end

Instance Method Details

#check_spaced_repetition_methods ⇒ Object 



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# File 'lib/spaced-repetition/sm2.rb', line 58

def check_spaced_repetition_methods
  begin
    send(:easiness_factor)
    send(:number_repetitions)
    send(:quality_of_last_recall)
    send(:next_repetition)
    send(:repetition_interval)
    send(:last_studied)
  rescue NoMethodError => e
    DBC.assert(false, e.message)
  end
end

#process_recall_result(quality_of_recall) ⇒ Object 



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# File 'lib/spaced-repetition/sm2.rb', line 22

def process_recall_result(quality_of_recall)
  DBC.require(quality_of_recall >= 0)
  DBC.require(quality_of_recall <= 5)
  DBC.require(easiness_factor)
  DBC.require(number_repetitions)
  
  if quality_of_recall < 3    
    self.number_repetitions = 0 
    self.repetition_interval = 0
  else
    self.easiness_factor = calculate_easiness_factor(easiness_factor, quality_of_recall)
  
    if quality_of_recall == 3
      self.repetition_interval = 0
    else
      self.number_repetitions += 1

      case number_repetitions
      when 1
        self.repetition_interval = 1
      when 2
        self.repetition_interval = 6
      else
        self.repetition_interval = repetition_interval * easiness_factor
      end
    end
  end
  
  self.next_repetition = Date.today + repetition_interval
  self.last_studied = Date.today
end

#reset_spaced_repetition_data ⇒ Object 



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# File 'lib/spaced-repetition/sm2.rb', line 13

def reset_spaced_repetition_data
  self.easiness_factor = 2.5  
  self.number_repetitions = 0  
  self.quality_of_last_recall = nil  
  self.repetition_interval = nil
  self.next_repetition = nil
  self.last_studied = nil
end

#scheduled_to_recall? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/spaced-repetition/sm2.rb', line 54

def scheduled_to_recall?
  !next_repetition.nil? && next_repetition <= Date.today
end