Module: Yanagi::Cyrillic

Defined in:
lib/yanagi/cyrillic.rb

Constant Summary collapse

O_COLUMN = 
%w[
  お こ そ と の ほ も よ ろ を
  ご ぞ ど ぼ ぽ
  きょ しょ ちょ にょ ひょ みょ りょ ぎょ じょ びょ ぴょ
  ふぉ ゔぉ
].freeze
U_COLUMN = 
%w[
  う く す つ ぬ ふ む ゆ る
  ぐ ず づ ぶ ぷ
  しゅ ちゅ じゅ きゅ ぎゅ にゅ ひゅ みゅ りゅ びゅ ぴゅ
  ゔ どぅ とぅ
].freeze
A_COLUMN = 
%w[
  あ か さ た な は ま や ら わ
  が ざ だ ば ぱ
  きゃ しゃ ちゃ にゃ ひゃ みゃ りゃ ぎゃ じゃ びゃ ぴゃ
  ふぁ ゔぁ
].freeze
E_COLUMN = 
%w[
  え け せ て ね へ め れ ゑ
  げ ぜ で べ ぺ
  しぇ ちぇ つぇ ふぇ うぇ ゔぇ
].freeze
I_COLUMN = 
%w[
  い き し ち に ひ み り ゐ
  ぎ じ ぢ び ぴ
  ふぃ ゔぃ てぃ でぃ
].freeze
GEMINATING_CONSONANTS =

Sokuon doubles only before the plosives «п» and «к», which Ukrainian carries comfortably (Іппекі, кеппекі, Ніккай, Хоккекьо). Before the sibilants and affricates it is not rendered: шш, чч and ддж read as foreign, so шічяку, Тешю, доджін-дзаші.

%w[п к].freeze

Class Method Summary collapse

Class Method Details

.call(input = nil, kanji: nil, reading: nil) ⇒ Object 



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# File 'lib/yanagi/cyrillic.rb', line 64

def self.call(input = nil, kanji: nil, reading: nil)
  raw_str = (reading || input).to_s.strip
  kanji_str = kanji.to_s.strip

  # 1. Whole-word exonym check
  exonyms = Rules.exonyms
  norm_key = Normalize.to_hiragana(Normalize.nfkc(raw_str))
  if exonyms.key?(norm_key.to_sym)
    entry = exonyms[norm_key.to_sym]
    return Result.new(
      text: entry[:cyrillic],
      source: :exonym,
      confidence: 1.0,
      notes: entry[:note] || "Exonym"
    )
  end

  # 2. Check exceptions table
  exceptions = Rules.exceptions
  if exceptions.is_a?(Array)
    match = exceptions.find do |e|
      (!kanji_str.empty? && e[:kanji] == kanji_str) ||
        e[:term] == raw_str ||
        e[:expected] == raw_str
    end
    if match
      return Result.new(
        text: match[:canonical] || match[:expected],
        source: :exception_table,
        confidence: 1.0,
        notes: match[:reason]
      )
    end
  end

  # 3. Check lexicon (if present)
  lexicon = Rules.lexicon
  if lexicon.is_a?(Hash) && !kanji_str.empty? && lexicon.key?(kanji_str.to_sym)
    entry = lexicon[kanji_str.to_sym]
    return Result.new(
      text: entry[:cyrillic] || entry[:reading_cyrillic],
      source: :lexicon,
      confidence: 1.0,
      notes: entry[:gloss]
    )
  end

  # 4. If input is romaji (only ASCII letters and apostrophes/hyphens/spaces)
  if raw_str.match?(/\A[a-zA-Z'\- ]+\z/)
    converted_kana = romaji_to_hiragana(raw_str)
    return render_kana(converted_kana)
  end

  # 5. Derived Cyrillic transliteration from kana
  render_kana(raw_str)
end

.geminate_consonant(next_rendered_text) ⇒ Object 



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# File 'lib/yanagi/cyrillic.rb', line 233

def self.geminate_consonant(next_rendered_text)
  return "" if next_rendered_text.nil? || next_rendered_text.empty?

  first_char = next_rendered_text[0]
  GEMINATING_CONSONANTS.include?(first_char) ? first_char : ""
end

.render_kana(kana_input) ⇒ Object 



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# File 'lib/yanagi/cyrillic.rb', line 121

def self.render_kana(kana_input)
  moras = Tokenizer.tokenize(kana_input)
  mora_map = Rules.mora_map

  # Step 1: Render each mora into candidate text (handling long vowel collapse and i diphthongs)
  rendered_segments = []

  moras.each_with_index do |mora, idx|
    prev_mora = idx > 0 ? moras[idx - 1] : nil

    case mora.kind
    when :passthrough
      rendered_segments << { mora: mora, text: mora.kana.to_s, kind: :passthrough }

    when :chouonpu
      # Long vowel mark collapses under policy
      rendered_segments << { mora: mora, text: "", kind: :chouonpu }

    when :sokuon
      # Sokuon is resolved in Step 2 with lookahead
      rendered_segments << { mora: mora, text: nil, kind: :sokuon }

    when :moraic_n
      # Moraic n is resolved in Step 2 with lookahead
      rendered_segments << { mora: mora, text: nil, kind: :moraic_n }

    when :syllable
      kana = mora.kana
      base_cyr = mora_map.dig(kana.to_sym, :cyrillic)&.to_s || kana

      # Long vowel collapse rules:
      # - う after O-column or U-column collapses
      if kana == "う" && prev_mora && prev_mora.syllable?
        if O_COLUMN.include?(prev_mora.kana) || U_COLUMN.include?(prev_mora.kana)
          rendered_segments << { mora: mora, text: "", kind: :collapsed_long_vowel }
          next
        end
      end

      # - お after O-column collapses (e.g. おおたけ -> Отаке)
      if kana == "お" && prev_mora && prev_mora.syllable? && O_COLUMN.include?(prev_mora.kana)
        rendered_segments << { mora: mora, text: "", kind: :collapsed_long_vowel }
        next
      end

      # - あ after A-column collapses
      if kana == "あ" && prev_mora && prev_mora.syllable? && A_COLUMN.include?(prev_mora.kana)
        rendered_segments << { mora: mora, text: "", kind: :collapsed_long_vowel }
        next
      end

      # - え after E-column collapses
      if kana == "え" && prev_mora && prev_mora.syllable? && E_COLUMN.include?(prev_mora.kana)
        rendered_segments << { mora: mora, text: "", kind: :collapsed_long_vowel }
        next
      end

      # - い diphthong vs vowel:
      #   い after E-column -> 'й' (e.g. めい -> мей, せんせい -> сенсей)
      #   い after A-column -> 'й' (e.g. しゅうさい -> шюсай, たい -> тай)
      #   い after U-column -> 'і' (e.g. かるいざわ -> каруідзава, ぬいもん -> нуімон)
      #   い after O-column -> 'і' (e.g. ごい -> ґоі, どい -> доі)
      #   い after I-column -> 'і' (e.g. きいん -> кіін, いいだ -> ііда, りいち -> ріічі)
      if kana == "い" && prev_mora && prev_mora.syllable?
        if E_COLUMN.include?(prev_mora.kana) || A_COLUMN.include?(prev_mora.kana)
          rendered_segments << { mora: mora, text: "й", kind: :syllable }
          next
        end
      end

      rendered_segments << { mora: mora, text: base_cyr, kind: :syllable }
    end
  end

  # Step 2: Resolve sokuon (っ) and moraic n (ん) based on next rendered segment
  final_parts = []
  rendered_segments.each_with_index do |seg, idx|
    if seg[:kind] == :sokuon
      # Find next non-empty rendered segment
      next_seg = rendered_segments[(idx + 1)..].find { |s| s[:text] && !s[:text].empty? }
      if next_seg
        next_text = next_seg[:text]
        geminated = geminate_consonant(next_text)
        final_parts << geminated if geminated
      end
    elsif seg[:kind] == :moraic_n
      # Find next non-empty rendered segment
      next_seg = rendered_segments[(idx + 1)..].find { |s| s[:text] && !s[:text].empty? }
      if next_seg && starts_with_labial?(next_seg[:text])
        final_parts << "м"
      else
        final_parts << "н"
      end
    else
      final_parts << seg[:text]
    end
  end

  Result.new(
    text: final_parts.join,
    source: :derived,
    confidence: 1.0,
    notes: nil
  )
end

.romaji_to_hiragana(str) ⇒ Object

Simple romaji to hiragana conversion for Mode A romaji input



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# File 'lib/yanagi/cyrillic.rb', line 247

def self.romaji_to_hiragana(str)
  norm = str.downcase.gsub("'", "'")
  mora_map = Rules.mora_map

  # Build inverted map from romaji -> hiragana kana
  @romaji_to_hira_table ||= begin
    table = {}
    mora_map.each do |kana_sym, data|
      rom = data[:romaji]&.to_s
      table[rom] = kana_sym.to_s if rom
    end
    # Sort by romaji length descending to match longest substrings first
    table.sort_by { |k, _v| -k.length }.to_h
  end

  res = []
  i = 0
  len = norm.length
  while i < len
    matched = false

    # Check sokuon in romaji (e.g. kk, pp, tt, ss, tch, ssh, etc.)
    c = norm[i]
    c_next = norm[i + 1]
    c3 = norm[i, 3]

    if c3 == "tch"
      res << "っ"
      i += 1
      next
    elsif c == c_next && c =~ /[bcdfghjklmpqrstvwxyz]/ && c != "n"
      res << "っ"
      i += 1
      next
    end

    # Match table
    @romaji_to_hira_table.each do |rom, kana|
      if norm[i..].start_with?(rom)
        res << kana
        i += rom.length
        matched = true
        break
      end
    end

    unless matched
      res << norm[i]
      i += 1
    end
  end

  res.join
end

.starts_with_labial?(text) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/yanagi/cyrillic.rb', line 240

def self.starts_with_labial?(text)
  return false if text.nil? || text.empty?
  # Labials: 'п', 'б'
  text.start_with?("п", "б")
end