Parsing "path" expression from AQL

[Heri Ramampiaro]

I am trying to implement a remove record field function that also can handle 
nested fields.

E.g.
let $r := {
"id": "2",
"address": {
        "street": "21 Orlando ct.",
        "city": "Irvine",
        "state": "CA"
}
"related": ["VXQuery", "AQL"]
}
return remove-field($r, [“address.state”]);

Expected result: 
[
{
"id": "2",
"address": {
        "street": "21 Orlando ct.",
        "city": "Irvine"
}
"related": ["VXQuery", "AQL"]
}
]

My question is how is the parser implemented to access nested field names?
(Or, where do I find the API for this?)

Thank you.

Best,
-heri