Question in slack about why a promise chan "returns the result of the promise every time you call".
The docstring in clj includes the phrase
Consumers will block until either a value is placed in the channel or the
channel is closed, then return the value (or nil) forever.
This is missing from the clojurescript version of the docstring:
Creates a promise channel with an optional transducer, and an optional
exception-handler. A promise channel can take exactly one value that consumers
will receive. Once full, puts complete but val is dropped (no transfer).
Consumers will block until either a value is placed in the channel or the
channel is closed. See chan for the semantics of xform and ex-handler.
source
