Class: JapaneseNames::Splitter

Inherits:
Object
  • Object
show all
Defined in:
lib/japanese_names/splitter.rb

Overview

Provides methods to split a full Japanese name strings into surname and given name.

Instance Method Summary collapse

Instance Method Details

#split(kanji, kana) ⇒ Object

Given a kanji and kana representation of a name splits into to family/given names.

The choice to prioritize family name is arbitrary. Further analysis is needed for whether given or family name should be prioritized.

Returns Array [[kanji_fam, kanji_giv], [kana_fam, kana_giv]] if there was a match. Returns nil if there was no match.



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# File 'lib/japanese_names/splitter.rb', line 13

def split(kanji, kana)
  return nil unless kanji && kana
  kanji = kanji.strip
  kana  = kana.strip

  # Short-circuit: Return last name if it can match the full string
  if kanji.size <= 3 && kana.size <= 4
    full_match = finder.find(kanji).detect { |d| d[0] == kanji && d[1] =~ /\A#{hk kana}\z/ }
    return [[kanji, nil], [kana, nil]] if full_match
  end

  # Partition kanji into candidate n-grams
  kanji_ngrams = Util::Ngram.ngram_partition(kanji)

  # Find all possible matches of all kanji n-grams in dictionary
  dict = finder.find(kanji_ngrams.flatten.uniq)

  first_lhs_match = nil
  first_rhs_match = nil
  kanji_ngrams.each do |kanji_pair|
    lhs_dict = dict.select { |d| d[0] == kanji_pair[0] }
    rhs_dict = dict.select { |d| d[0] == kanji_pair[1] }

    lhs_match = detect_lhs(lhs_dict, kanji, kana)
    rhs_match = detect_rhs(rhs_dict, kanji, kana)

    return lhs_match if lhs_match && lhs_match == rhs_match

    first_lhs_match ||= lhs_match
    first_rhs_match ||= rhs_match
  end

  # As a fallback, return single-sided match prioritizing surname match first
  first_lhs_match || first_rhs_match
end