moving scale stuff to separate class

spec/notes_spec.cr

@@ -1,15 +1,6 @@
 require "./spec_helper"
 
 describe Medley::Notes do
-  describe "#by_scale" do
-    pending "returns an array of letters in C major scale order" do
-      Medley::Notes.by_scale("Cmaj").should eq(["C", "D", "E", "F", "G", "A", "B", "C"])
-    end
-
-    pending "returns an array of letters in F major scale order" do
-      Medley::Notes.by_scale("Fmaj").should eq(["F", "G", "A", "Bb", "C", "D", "E", "F"])
-    end
-  end
 
   describe ".halfstep_up" do
     it "returns G# when given G" do

spec/scales_spec.cr

@@ -0,0 +1,16 @@
+require "./spec_helper"
+
+describe Medley::Scales do
+
+  describe ".notes" do
+    it "returns an array of letters in C major scale order" do
+      scale = Medley::Scales.new("Cmaj")
+      scale.notes.should eq(["C", "D", "E", "F", "G", "A", "B", "C"])
+    end
+
+    it "returns an array of letters in F major scale order" do
+      scale = Medley::Scales.new("Fmaj")
+      scale.notes.should eq(["F", "G", "A", "Bb", "C", "D", "E", "F"])
+    end
+  end
+end

src/medley/notes.cr

@@ -3,12 +3,6 @@ module Medley
     NOTE_NAMES = %w(A B C D E F G)
     ALIASES = {"B#": "C", "Cb": "B", "E#": "F", "Fb": "E"}
 
-    # 1 1 .5 1 1 1 .5
-    def self.by_scale(scale : String)
-      scale.match(/(\w+)(maj|min)/)
-
-    end
-
     def initialize(current_note : String)
       @current_note = current_note
     end

src/medley/scales.cr

@@ -0,0 +1,38 @@
+module Medley
+  class Scales
+    PATTERNS = {
+      "maj": %w(1 1 .5 1 1 1 .5),
+      "min": %w(1 .5 1 1 .5 1 1)
+    }
+
+    @pattern : Array(String)
+    @root : String
+    #@notes : Array(String)
+
+    def initialize(scale : String)
+      scale.match(/(\w+)(maj|min)/)
+      @pattern = PATTERNS[$2]
+      @root = $1
+      @notes = [] of String
+      build_scale
+    end
+
+    def notes
+      @notes
+    end
+
+    private def build_scale
+      note = Medley::Notes.new(@root)
+      @notes << note.name
+      @pattern.each do |step|
+        case step
+        when "1"
+          @notes << note.wholestep_up
+        when ".5"
+          @notes << note.halfstep_up
+        end
+        note = Medley::Notes.new(@notes.last)
+      end
+    end
+  end
+end