Can a subscriber layer create new spans?

[miikka]

A library that I use produces tracing events. I'd like to consume some of these events and replace them with spans to get more informative traces. Is this possible?

I thought I'd create a Layer, but looks like layers can't create new spans and I'd actually need a Subscriber for that - but Subscribers cannot be easily composed.

[davidbarsky]

Not really, and you also run the risk of an infinite span loop: basically, layers aren't able to map spans/events.