Create RFC 6902 style patches between JSON objects.
For example, json_diff({a: [9, 7]}, {a: [9, 8, 7]}) results in
[{op: 'add', path: '/a/1', value: 8}].
No cyclic references are allowed in the objects being compared. The algorithm computes differences between arrays in a way similar to the diff utility, so it will become slow for large arrays of complex objects.