Implementing a workflow graph
Goal Implement a struct which holds the workflow graph and yields the next values in line for execution. Workflow Graph When writing a workflow management engine, one has to decide on the data structure of the workflow. I decided to go for the most common one: A directed acyclic graph, in short DAG. I thought about using a more open type, i. e. a cyclic graph, but that has really weird implications for a retry system and output handling....