Class: HeadMusic::Notation::MusicXML::LyricWriter

Inherits:
Object
  • Object
show all
Includes:
XmlText
Defined in:
lib/head_music/notation/music_xml/lyric_writer.rb

Overview

Serializes the children of a note.

One instance serves a whole document so the walk back to the previous sung note — which decides whether a syllable begins, continues, or ends a word — is memoized per voice and verse.

Instance Method Summary collapse

Instance Method Details

#escape(text) ⇒ Object (private) Originally defined in module XmlText

#lines(placement, component, chord:) ⇒ Object

is the last child of . Sung text rides only the lead note of a chord and only the attack of a tied chain (a tie_stop component is a continuation, sung once at the start). Held notes of a melisma carry no syllable and so emit nothing, matching MusicXML's continuation-by-absence. 


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# File 'lib/head_music/notation/music_xml/lyric_writer.rb', line 17

def lines(placement, component, chord:)
  return [] if chord || placement.rest? || component.tie_stop

  placement.syllables.keys.sort.flat_map do |verse|
    syllable = placement.syllables[verse]
    [
      %(#{INDENT * 4}<lyric number="#{verse}">),
      "#{INDENT * 5}<syllabic>#{syllabic(placement, syllable)}</syllabic>",
      "#{INDENT * 5}<text>#{escape(syllable.text)}</text>",
      "#{INDENT * 4}</lyric>"
    ]
  end
end

#previous_syllable(placement, verse) ⇒ Object (private)

The syllable on the nearest earlier placement in the same voice carrying text for this verse. Placements are position-sorted, and melisma gaps are skipped because only sung placements are collected. Array#index compares with ==, which on Placement is position-only, but a voice holds at most one placement per position (Voice#insert_into_placements), so that still locates this exact placement.



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# File 'lib/head_music/notation/music_xml/lyric_writer.rb', line 50

def previous_syllable(placement, verse)
  @sung_placements ||= {}
  sung = @sung_placements[[placement.voice, verse]] ||=
    placement.voice.placements.select { |candidate| candidate.syllable(verse) }
  index = sung.index(placement)
  return nil if index.nil? || index.zero?

  sung[index - 1].syllable(verse)
end

#syllabic(placement, syllable) ⇒ Object (private)

Derives MusicXML’s single/begin/middle/end from our stored hyphen_after booleans: this syllable’s, and the previous sung note’s for the same verse.



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# File 'lib/head_music/notation/music_xml/lyric_writer.rb', line 35

def syllabic(placement, syllable)
  from_previous = previous_syllable(placement, syllable.verse)&.hyphen_after?
  if from_previous
    syllable.hyphen_after? ? "middle" : "end"
  else
    syllable.hyphen_after? ? "begin" : "single"
  end
end