circle.rb in head_music-0.23.2

- old
+ new

@@ -1,11 +1,11 @@
 # frozen_string_literal: true
 
+require 'head_music/interval_cycle'
+
 # A Circle of Fifths or Fourths shows relationships between pitch classes
-# TODO: Replace or empower with IntervalCycle (?)
-# https://en.wikipedia.org/wiki/Interval_cycle
-class HeadMusic::Circle
+class HeadMusic::Circle < HeadMusic::IntervalCycle
   def self.of_fifths
     get(7)
   end
 
   def self.of_fourths
@@ -17,10 +17,11 @@
     @circles[interval.to_i] ||= new(interval)
   end
 
   attr_reader :interval, :pitch_classes
 
+  # Accepts an interval (as an integer number of semitones)
   def initialize(interval)
     @interval = interval.to_i
     @pitch_classes = pitch_classes_by_interval
   end
 
@@ -30,16 +31,13 @@
 
   private_class_method :new
 
   private
 
-  def pitch_classes_by_interval
-    [HeadMusic::PitchClass.get(0)].tap do |list|
-      loop do
-        next_pitch_class = list.last + interval
-        break if next_pitch_class == list.first
+  def interval_cycle
+    @interval_cycle ||= HeadMusic::IntervalCycle.get(interval)
+  end
 
-        list << next_pitch_class
-      end
-    end
+  def pitch_classes_by_interval
+    interval_cycle.send(:pitch_classes_by_interval)
   end
 end