sourceafJson::JsonConverter.fan

** Implement to convert custom Fantom types to / from a JSON representation. 
@Js const mixin JsonConverter {
    
    ** Converts a Fantom object to its JSON representation. 
    ** 
    ** Must return a valid JSON value (or a List or Map thereof).
    ** 
    ** 'fantomObj' is nullable so converters can create empty / default objects.
    abstract Obj? toJsonVal(Obj? fantomObj, JsonConverterCtx ctx)

    ** Converts a JSON value to Fantom.
    ** 
    ** 'jsonVal' is nullable so converters can create empty / default objects.
    abstract Obj? fromJsonVal(Obj? jsonVal, JsonConverterCtx ctx)
    
}