Adding Fiber Information to Custom Logger

Sorry, one more question. I have written my own logger with Logger.make which I pass with Logger.replace. With each message I log, I want to show the id of the fiber that sent it. And also, because that's often useful, I want to show the parent chain of that fiber. So if, for instance, the message was sent by fiber 10 which was spawned by fiber 9 which was spawned by fiber 8, I want to see:
10|9|8: my message
Now I have two issues. First, I see an ids method in Fiber.ts. But it returns an array of ids for each fiberId it receives. It seems to be linked to there being runtime and composite fiberIds. I don't quite understand the difference between the 2. In my case, each fiberId I receive through Logger.make should always be a runtime fiberId no? Are there cases when it could be a composite fiberId?
Second, given a fiberId, how do I get to the fiberId of the parent of the fiber having that fiberId?
Was this page helpful?