Borrowing the example from Gson's TypeAdapter, we will create a Point class that can revive strings like "5,8". Let's see how the reviver looks like:
constreviver=(k, v)=> Point.of(...v.split(','))
Note: a third path argument is forwarded by the built-in revivers, mostly to help display more informative error messages when necessary. JSON.parse(..., reviver) would not forward a path as it is not part of the native API.
With that, we are ready to create our Point class: