Traverse tree with results. Maybe type in Java?
- by Angelo.Hannes
I need to check a tree's node state. It can either be OK or NOT_OK. But that state is dependent on its children. So for a node to be OK, every of its children needs to be OK. If one or more of its children is NOT_OK the whole node is NOT_OK. To determine the state of a node I need to aggregate some properties of the node.
So I thought of two possible implementations. And they are more or less covered in this question: Why is Option/Maybe considered a good idea and checked exceptions are not?
Exception
I could pass the properties up the recursion path, and throw an exception if something went wrong.
Maybe
I implement an Maybe type and let it either hold an error or the aggregated properties. Maybe it is more an Either.
I tend towards the last option. And I'm thinking of an enum with two objects. Where I can additionally set those aggregated properties.
Am I on the right track?
I'm not familiar with the new JDK8 functional stuff. But I'm stuck on JDK7 anyway, so please focus on JDK7.
