JSON Full Support

[mxwli]

API

Python

Description

The JSON extension is largely implemented, but there are still a few things that are missing. See #3609 for details on the full feature list.

Pretty much all JSON functions where the second parameter is STRING[] | STRING, (eg. json_keys, json_array_length) only support STRING, rather than STRING[]. Generally second parameters in the form of the list are expanded in the following way: json_keys(item, [key1, key2, key3]) gives the same result as [json_keys(item, key1), json_keys(item, key2), json_keys(item, key3)]

json_array and json_object are unimplemented.