The YAML Stack
     
     Loader Stack        Memory Representation         Dumper Stack
     ==============================================================
           Loader                                      Dumper
                    \                              /
                       (Native Perl Data/Objects)
                    /                              \
      Constructor                                      Representer
                    \                              /
                            (YAML Node Graph)
                    /                              \
         Composer      <-->     Resolver     <-->      Serializer
                    \                              /
                            (YAML Event Tree)
                    /                              \
           Parser                                      Emitter
                    \                              /
                           (YAML Token Stream)
                    /                              /
          Scanner
                    \                              /
                         (YAML Character Stream)
                    /                              \
           Reader                                      Writer
                    \                              /
                      (YAML String or File Handle)