:sig
String json_encode(String s)
String json_encode(DTree t)

:params
s : string to encode as a JSON string literal
t : DTree object to be serialized
return value : string containing the JSON result

:desc
Serializes either a `String` or a `DTree` into JSON notation.

When passed a `String`, `json_encode()` returns a quoted and escaped JSON string literal.

When passed a `DTree`, scalar values are serialized directly and nested map values are emitted as JSON objects.

:related
**PHP:** `json_encode()`
**JavaScript / Node.js:** `JSON.stringify()`
