visit_Psych_Nodes_Mapping

# File ext/psych/lib/psych/visitors/to_ruby.rb, line 139
      def visit_Psych_Nodes_Mapping o
        return revive(Psych.load_tags[o.tag], o) if Psych.load_tags[o.tag]
        return revive_hash({}, o) unless o.tag

        case o.tag
        when /^!(?:str|ruby\/string)(?::(.*))?/, 'tag:yaml.org,2002:str'
          klass = resolve_class($1)
          members = Hash[*o.children.map { |c| accept c }]
          string = members.delete 'str'

          if klass
            string = klass.allocate.replace string
            register(o, string)
          end

          init_with(string, members.map { |k,v| [k.to_s.sub(/^@/, ''),v] }, o)
        when /^!ruby\/array:(.*)$/
          klass = resolve_class($1)
          list  = register(o, klass.allocate)

          members = Hash[o.children.map { |c| accept c }.each_slice(2).to_a]
          list.replace members['internal']

          members['ivars'].each do |ivar, v|
            list.instance_variable_set ivar, v
          end
          list
        when /^!ruby\/struct:?(.*)?$/
          klass = resolve_class($1)

          if klass
            s = register(o, klass.allocate)

            members = {}
            struct_members = s.members.map { |x| x.to_sym }
            o.children.each_slice(2) do |k,v|
              member = accept(k)
              value  = accept(v)
              if struct_members.include?(member.to_sym)
                s.send("#{member}=", value)
              else
                members[member.to_s.sub(/^@/, '')] = value
              end
            end
            init_with(s, members, o)
          else
            members = o.children.map { |c| accept c }
            h = Hash[*members]
            Struct.new(*h.map { |k,v| k.to_sym }).new(*h.map { |k,v| v })
          end

        when '!ruby/range'
          h = Hash[*o.children.map { |c| accept c }]
          register o, Range.new(h['begin'], h['end'], h['excl'])

        when /^!ruby\/exception:?(.*)?$/
          h = Hash[*o.children.map { |c| accept c }]

          e = build_exception((resolve_class($1) || Exception),
                              h.delete('message'))
          init_with(e, h, o)

        when '!set', 'tag:yaml.org,2002:set'
          set = Psych::Set.new
          @st[o.anchor] = set if o.anchor
          o.children.each_slice(2) do |k,v|
            set[accept(k)] = accept(v)
          end
          set

        when '!ruby/object:Complex'
          h = Hash[*o.children.map { |c| accept c }]
          register o, Complex(h['real'], h['image'])

        when '!ruby/object:Rational'
          h = Hash[*o.children.map { |c| accept c }]
          register o, Rational(h['numerator'], h['denominator'])

        when /^!ruby\/object:?(.*)?$/
          name = $1 || 'Object'
          obj = revive((resolve_class(name) || Object), o)
          obj

        when /^!map:(.*)$/, /^!ruby\/hash:(.*)$/
          revive_hash resolve_class($1).new, o

        when '!omap', 'tag:yaml.org,2002:omap'
          map = register(o, Psych::Omap.new)
          o.children.each_slice(2) do |l,r|
            map[accept(l)] = accept r
          end
          map

        else
          revive_hash({}, o)
        end
      end