Class: MusicalSpec::Note

Inherits:
Object
  • Object
show all
Includes:
Comparable
Defined in:
lib/musical_spec/note.rb

Overview

Uses scientific notation, e.g. C4 is middle C.

Constant Summary collapse

SCALE_PROGRESSION = 
%w(C D E F G A B)

Instance Method Summary collapse

Constructor Details

#initialize(desired_note_string = nil) ⇒ Note

Takes 1 optional argument, a note string like “C4”.



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# File 'lib/musical_spec/note.rb', line 9

def initialize(desired_note_string = nil)
  self.note = desired_note_string || LOWEST_NOTE.to_s
end

Instance Method Details

#higher! ⇒ Object

Increase the pitch, handling octave changes. Will not go above MusicalSpec::HIGHEST_NOTE.



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# File 'lib/musical_spec/note.rb', line 29

def higher!
  if below_highest_note?
    if @letter == SCALE_PROGRESSION.last
      @letter = SCALE_PROGRESSION.first
      @octave += 1
    else
      @letter = SCALE_PROGRESSION[SCALE_PROGRESSION.index(@letter) + 1]
    end
  end
end

#lower! ⇒ Object

Decrease the pitch, handling octave changes. Will not go below MusicalSpec::LOWEST_NOTE.



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# File 'lib/musical_spec/note.rb', line 42

def lower!
  if above_lowest_note?
    if @letter == SCALE_PROGRESSION.first
      @letter = SCALE_PROGRESSION.last
      @octave -= 1
    else
      @letter = SCALE_PROGRESSION[SCALE_PROGRESSION.index(@letter) - 1]
    end
  end
end

#note=(new_note) ⇒ Object

Set the note to a new one, e.g. ‘note.note = ’A5’‘



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# File 'lib/musical_spec/note.rb', line 19

def note=(new_note)
  new_letter, new_octave = new_note.split('')
  @letter = new_letter
  @octave = new_octave.to_i

  to_s
end

#to_s ⇒ Object

A string like “C4”.



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# File 'lib/musical_spec/note.rb', line 14

def to_s
  "#{letter}#{octave}"
end