Class: HeadMusic::Notation::LilyPond::DurationWriter

Inherits:
Object
  • Object
show all
Defined in:
lib/head_music/notation/lily_pond/duration_writer.rb

Overview

Converts one link of a rhythmic value into a LilyPond duration token. Ties between links are the caller’s concern (RenderPlan joins links with the tie mark), so this writer ignores tied_value.

Constant Summary collapse

DURATIONS_BY_UNIT_NAME =

LilyPond durations are symbolic: a power-of-two number, or a named command for the values longer than a whole note.

{
  "maxima" => "\\maxima",
  "longa" => "\\longa",
  "double whole" => "\\breve",
  "whole" => "1",
  "half" => "2",
  "quarter" => "4",
  "eighth" => "8",
  "sixteenth" => "16",
  "thirty-second" => "32",
  "sixty-fourth" => "64",
  "hundred twenty-eighth" => "128",
  "two hundred fifty-sixth" => "256"
}.freeze

Class Method Summary collapse

Class Method Details

.token(rhythmic_value) ⇒ Object 



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# File 'lib/head_music/notation/lily_pond/duration_writer.rb', line 24

def self.token(rhythmic_value)
  value = HeadMusic::Rudiment::RhythmicValue.get(rhythmic_value)
  base = DURATIONS_BY_UNIT_NAME.fetch(value.unit_name) do
    raise RenderError, "no LilyPond duration is known for a #{value.unit_name} note"
  end
  base + "." * value.dots
end