Hash的深层merge

gistfile1.rb

class Hash
    def deep_merge!(other_hash)
      other_hash.each_pair do |k, v|
        tv = self[k]
        self[k] = tv.is_a?(Hash) && v.is_a?(Hash) ? tv.deep_merge(v) : v
      end
      self
    end

    def deep_merge(other_hash)
      dup.deep_merge!(other_hash)
    end
end