How to differentiate between null and not existing?

[ck-c8y]

1. When I evaluate the expression nullField against the document:
   { "nullField": null }
   I get null.

2. When I evaluate the expressions nonExistingField against the same document I still get: null.

When I run the same test in the JSONata Exerciser I get:

1. null
2. ** no match **

How can I differentiate these two cases in jsonata-java ?

[aeberhart]

Right now you cannot. This is a design decision in order to avoid having to use a JSON lib like Jackson (see README).
Internally, we use an Object to represent null: see:

com.dashjoin.jsonata.Jsonata.NULL_VALUE
com.dashjoin.jsonata.Utils.convertNulls(Object)

We could introduce a mode that sends this to the caller. Did not do that because seemed unintuitive to have to check for null and NULL_VALUE