extract-keywords.rb

# coding: utf-8
require 'kuromoji'

while title = ARGF.gets
  result = Kuromoji.tokenize(title).to_a
  puts result.sort {|word1, word2|
    word1_chars = word1[1].split(',')
    word2_chars = word2[1].split(',')
    word1_class = word1_chars.first
    word2_class = word2_chars.first
    res = case
          when word1_class == word2_class
            -1
          when word1_class == '名詞'
            -1
          when word2_class == '名詞'
            1
          when word1_class == '形容詞'
            -1
          when word2_class == '形容詞'
            1
          else
            -1
          end
    res
  }.select {|(word, characteristics)|
    word.match(/\A(?:\w|\p{Hiragana}|\p{Katakana}|\p{Han})+\z/) and
      characteristics.split(',')[1] != '数'
  }.take(2).collect {|(word, characteristics)|
    word
  }.join("\t")
end