single value enum and API pattern

[dontcallmedom]

Following #300 the PressureSource enum has a single value; I understand the goal is to keep thermals as a possible future extension, but conversely, it would be unfortunate if such a future extension never sees the light and developers have to keep using observe("cpu") for ever for no good reason.

I wonder if this points toward a possible alternative structure for the API, where observe() would be applied to an object representing the source (e.g. cpu.observe()).

[kenchris]

We do want to expand this to other types in the future, and this is already shipping in Chrome and Edge, so that would be a major change. Also we are trying to avoid having too many objects in the platform.

[dontcallmedom]

ok, thanks; no need to keep the issue open then