Function FLEncodeApplyingJSONDelta 

pub unsafe extern "C" fn FLEncodeApplyingJSONDelta(
    old: FLValue,
    jsonDelta: FLSlice,
    encoder: FLEncoder,
) -> bool

Applies the (parsed) JSON data created by CreateJSONDelta to the value old, which must be equal to the old value originally passed to FLCreateJSONDelta, and writes the corresponding nuu value to the encoder. @param old A value that’s typically the old/original state of some data. This must be equal to the old value used when creating the jsonDelta. @param jsonDelta A JSON-encoded delta created by FLCreateJSONDelta or FLEncodeJSONDelta. @param encoder A Fleece encoder to write the decoded nuu value to. (JSON encoding is not supported.) @return True on success, false on error; call FLEncoder_GetError for details.