monadic 0.8.0
brings some functional goodness to ruby by giving you some monads
          Gemfile:
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          インストール:
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      Development依存関係 (8):
            activesupport
            >= 0
          
          
            growl
            >= 0
          
          
            guard
            >= 0
          
          
            guard-bundler
            >= 0
          
          
            guard-rspec
            >= 0
          
          
            rake
            >= 0
          
          
            rb-fsevent
            ~> 0.9.1
          
          
            rspec
            >= 2.9.0
          
    