Synchronously wrap asynchronous code — synchronise • async

Evaluate an expression in an async phase. It creates an event loop, then evaluates the supplied expression. If its result is a deferred value, it keeps running the event loop, until the deferred value is resolved, and returns its resolved value.

synchronise(expr)

Arguments

expr: Async function call expression. If it does not evaluate to a deferred value, then it is just returned.

Details

If an error is not handled in the async phase, synchronise() will re-throw that error.

synchronise() cancels all async processes on interrupt or external error.

Examples

# \donttest{
http_status <- function(url, ...) {
  http_get(url, ...)$
    then(function(x) x$status_code)
}

synchronise(http_status("https://eu.httpbin.org/status/418"))
#> [1] 418
# }