Sources

A source is just the interface that all observables implement, which also gives them some default operators. Treating everything as a Source like this was a way to speed up development at the cost of semantics. Down the road when/if this library gains more adoption, that will likely change.

While some vary, most Sources have a few basic constructors

Observable(just = "emit only this string and complete")
Observable(error = Throwable("notify downstream we're dead"))
Observable(createWithEmitter = { emitter -> } // Useful for creating origin sources