# File lib/text/format.rb, line 318 318: def hyphenator=(h) 319: raise ArgumentError, "#{h.inspect} is not a valid hyphenator." unless h.respond_to?(:hyphenate_to) 320: arity = h.method(:hyphenate_to).arity 321: raise ArgumentError, "#{h.inspect} must have exactly two or three arguments." unless [2, 3].include?(arity) 322: @hyphenator = h 323: @hyphenator_arity = arity 324: end