> You wouldn't say that objects/dicts in JSON are irrelevant, would you?

I kind of would. Coming from Erlang, I don't see a point to there being a whole separate syntax for encoding object/map types. Just encode objects/maps as arrays of pairs (2-Tuples, or just length-2 arrays).

Then, if you want ser-des type fidelity, stick an annotation onto the array (like in YAML) to say what type it should decode to.

E.g., something like:

    [1, 2, 3] # array
    [['a', 1], ['b', 2], ['c', 3]] # array of pairs
    [@object, ['a', 1], ['b', 2], ['c', 3]] # array of pairs hinted so it should decode to an Object
    [@map, ['a', 1], ['b', 2], ['c', 3]] # array of pairs hinted so it should decode to a Map

The nice thing about this approach is that JSON libraries could do as much or as little work in parsing out the annotations as they want: they could recognize the annotations and construct the referred-to type; or they could just pass back the array with the annotation expressed as an Annotation value.