Class: HeadMusic::Style::Guidelines::PrepareOctaveLeaps

Inherits:
Annotation
  • Object
show all
Defined in:
lib/head_music/style/guidelines/prepare_octave_leaps.rb

Overview

A counterpoint guideline

Constant Summary collapse

MESSAGE = 
"Enter and exit an octave leap from within."

Instance Method Summary collapse

Constructor Details

This class inherits a constructor from HeadMusic::Style::Annotation

Instance Method Details

#external_entries ⇒ Object (private) 



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# File 'lib/head_music/style/guidelines/prepare_octave_leaps.rb', line 32

def external_entries
  external_leaps { |first, second| second.octave? && !second.spans?(first.pitches.first) }
end

#external_entries_marks ⇒ Object (private) 



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# File 'lib/head_music/style/guidelines/prepare_octave_leaps.rb', line 14

def external_entries_marks
  external_entries.map do |trouble_spot|
    HeadMusic::Style::Mark.for_all(trouble_spot)
  end
end

#external_exits ⇒ Object (private) 



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# File 'lib/head_music/style/guidelines/prepare_octave_leaps.rb', line 36

def external_exits
  external_leaps { |first, second| first.octave? && !first.spans?(second.pitches.last) }
end

#external_exits_marks ⇒ Object (private) 



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# File 'lib/head_music/style/guidelines/prepare_octave_leaps.rb', line 20

def external_exits_marks
  external_exits.map do |trouble_spot|
    HeadMusic::Style::Mark.for_all(trouble_spot)
  end
end

#external_leaps ⇒ Object (private)

Adjacent melodic-interval pairs whose octave leap is approached or left from outside the span, as decided by the given predicate.



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# File 'lib/head_music/style/guidelines/prepare_octave_leaps.rb', line 42

def external_leaps
  melodic_note_pairs.each_cons(2).filter_map do |pair|
    first, second = *pair
    pair.map(&:notes).flatten.uniq if yield(first, second)
  end
end

#marks ⇒ Object 



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# File 'lib/head_music/style/guidelines/prepare_octave_leaps.rb', line 8

def marks
  external_entries_marks + external_exits_marks + octave_ending_marks
end

#octave_ending ⇒ Object (private) 



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# File 'lib/head_music/style/guidelines/prepare_octave_leaps.rb', line 49

def octave_ending
  octave_ending? ? melodic_note_pairs.last.notes : []
end

#octave_ending? ⇒ Boolean (private)

Returns:

  • (Boolean) 


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# File 'lib/head_music/style/guidelines/prepare_octave_leaps.rb', line 53

def octave_ending?
  melodic_note_pairs.last&.octave?
end

#octave_ending_marks ⇒ Object (private) 



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# File 'lib/head_music/style/guidelines/prepare_octave_leaps.rb', line 26

def octave_ending_marks
  return [] unless octave_ending?

  [HeadMusic::Style::Mark.for_all(octave_ending)]
end