Nicolas Grekas has submitted about a new tool he's developed to "represent faithfully any PHP variable as complex as it is" - Patchwork-Doc (related to his Patchwork PHP framework).

The JSON format on which it rests guarantees maximum interoperability while ensuring good readability. The implementation done in the JsonDumper class operates all potentialities of the representation while providing maximum latitude to the developer to exploit its ability as desired, both in term of exposure of internal class mechanism for specialization and in terms of custom use, thanks to the callbacks that allow to intercept the JSON line by line and to adjust the dumping of objects or resources according to their type.

It isn't required to use the framework to use this tool, however. You can see an example of the output format in this example on the project's github page, complete with a guide to some of the advantages and disadvantages of some of the current, more common methods of output. Several types are included in the example including simple string/integer values, objects, classes, stream resources and the results of variable casting.