Calculate chord by given Key (Ver 0.1)

guitar_chord.rb

require "Set"
require "./mode_scale.rb"
class GuitarChord
	attr_accessor :key
	@@scale 	= ["C","#C/bD","D","#D/bE","E","F","#F/bG","G","#G/bA","A","#A/bB","B"]
	@@chord_hash = {
		# Major chords
		"maj" 	=> [0,4,3],
		"maj7"	=> [0,4,3,4],
		"M7"	=> [0,4,3,3],
		"add9"  => [0,4,3,7],
		"maj9"	=> [0,4,3,4,3],
		"M9"	=> [0,4,3,3,4],
		# Minor chords
		"min" 	=> [0,3,4]
		
	}	
	def initialize(key)
		@key = key 
		@chord = Set.new
	end
	
	def to_s
		"KEY: #{key}"
	end
	
	def clac_chord(type)
		pos = @@scale.index(key)
		@chord.clear
		for i in @@chord_hash[type]
			pos += i
			pos %= 12
			@chord << @@scale[pos]
		end
		@chord.to_a
	end
	
	def maj ; 	clac_chord("maj"); 	end
	def maj7; 	clac_chord("maj7"); end
	def M7; 	clac_chord("M7");	end
	def add9;	clac_chord("add9"); end
	def maj9;	clac_chord("maj9");	end
	def M9;		clac_chord("M9");	end
	def min;	clac_chord("min");	end
	
	def recmandMode
		var = ModeScale.new(key,"Ionian")
		
	end
end

# MAIN PROGRAM
a = GuitarChord.new("A")
p a.maj
p a.min
p a.add9
p a.maj9

=begin
# OUTPUT:
["A", "#C/bD", "E"]
["A", "C", "E"]
["A", "#C/bD", "E", "B"]
["A", "#C/bD", "E", "#G/bA", "B"]
=end

mode_scale

require "Set"
class ModeScale
	
	attr_accessor :key, :mode
	attr_reader :mode_scale
	def initialize(key, mode)
		@key, @mode = key, mode
		showScale
	end
	
	
	def to_s
		"KEY:#{@key} in #{@mode} \n" +
		"Scale: #{@mode_scale.to_a}"
	end
	
	
	def showScale
		scale 	= ["C","#C/bD","D","#D/bE","E","F","#F/bG","G","#G/bA","A","#A/bB","B"]
		@mode_scale= Set.new
		
		mode_hash = {
			# 1 means a semitone and 2 means two semitone
			"Ionian" 	=> [0,2,2,1,2,2,2,1],
			"Dorian"	=> [0,2,1,2,2,2,1,2],
			"Phrygian"	=> [0,1,2,2,2,1,2,2],
			"Lydian"	=> [0,2,2,2,1,2,2,1],
			"Mixolydian"=> [0,2,2,1,2,2,1,2],
			"Aeolian"	=> [0,2,1,2,2,1,2,2],
			"Locrian"	=> [0,1,2,2,1,2,2,2]
		}
		# ==============================
		pos = scale.index(key)
		for i in (0..7) 
			pos += (mode_hash[mode]).at(i)
			pos %= 12
			@mode_scale << scale[pos]
		end
		# ==============================
	end

	
end