Module: ToChitanda::Kansuuji

Extended by:
Kansuuji
Included in:
Kansuuji
Defined in:
lib/to_chitanda/kansuuji.rb

Constant Summary collapse

KANJI_NUMBERS = 
%w(〇 一 二 三 四 五 六 七 八 九)
LOWER_RANKS = 
[nil] + %w(十 百 千)
UPPER_RANKS = 
[nil] + %w(万 億 兆)
MAX_NUMBER = 
1_0000_0000_0000_0000

Instance Method Summary collapse

Instance Method Details

#kansuuji(number) ⇒ Object

Raises:

  • (ArgumentError) 


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# File 'lib/to_chitanda/kansuuji.rb', line 12

def kansuuji(number)
  raise ArgumentError, "can't calculate negative number" if number < 0
  raise ArgumentError, "can't calculate gte #{MAX_NUMBER}" if number >= MAX_NUMBER
  return KANJI_NUMBERS[0] if number == 0

  ranks   = UPPER_RANKS.dup
  results = []

  while number > 0
    number, lower = number.divmod(10000)
    results << "#{kansuuji_lower(lower, ranks.shift)}"
  end

  results.reverse.join
end