Thanks for the tip. Data::Diver seems to do part of what is needed, but I doubt it's a platform to build on. The reason is that the technique being used is somewhat limited. A better approach is to just use a string, and parse it, for full control.

I've seen that there are a couple of specs for technologies out there that are JSON related (JSON Schema, JSON Xpath). Once someone implements these, they'll probably be the way to go.