On Tuesday, 19 July 2022 at 15:30:30 UTC, Bienlein wrote:
If the destination of a carrier was set to null, it implied that the destination was currently undefined. Then the robot brought the carrier to some rack where it was put aside for a while till the planning system had created a new production plan. The number of null pointer exceptions we had to fix because auf this was countless. Never make null imply some meaning ...
This is due to a lack of proper abstractions. Null always has a meaning, if it didn't, you would not need it. In this particular case you could have used a singleton instead.
In a relational database you can choose between having null or having a large number of tables. The latter performs poorly. I am not talking about how to implement null, I am talking about the concept of information being absent. If you have to represent that, you have a defacto "null", doesn't matter if it is a singleton or address zero or NaN or FFFE (for unicode).
