# File text/format.rb, line 315 315: def hyphenator=(h) 316: raise ArgumentError, "#{h.inspect} is not a valid hyphenator." unless h.respond_to?(:hyphenate_to) 317: arity = h.method(:hyphenate_to).arity 318: raise ArgumentError, "#{h.inspect} must have exactly two or three arguments." unless [2, 3].include?(arity) 319: @hyphenator = h 320: @hyphenator_arity = arity 321: end