Combine multiple promise objects
Use promise_all to wait for multiple promise objects to all be successfully
fulfilled. Use promise_race to wait for the first of multiple promise
objects to be either fulfilled or rejected.
promise_all(..., .list = NULL) promise_race(..., .list = NULL)
... |
Promise objects. Either all arguments must be named, or all
arguments must be unnamed. If |
.list |
A list of promise objects–an alternative to |
A promise.
For promise_all, if all of the promises were successful, the returned
promise will resolve to a list of the promises' values; if any promise
fails, the first error to be encountered will be used to reject the
returned promise.
For promise_race, the first of the promises to either fulfill or reject
will be passed through to the returned promise.
p1 <- promise(~later::later(~resolve(1), delay = 1))
p2 <- promise(~later::later(~resolve(2), delay = 2))
# Resolves after 1 second, to the value: 1
promise_race(p1, p2) %...>% {
cat("promise_race:\n")
str(.)
}
# Resolves after 2 seconds, to the value: list(1, 2)
promise_all(p1, p2) %...>% {
cat("promise_all:\n")
str(.)
}Please choose more modern alternatives, such as Google Chrome or Mozilla Firefox.