Repeatedly call task until it its test function returns TRUE — async_until • async

Repeatedly call task until it its test function returns TRUE

async_until(test, task, ...)

Arguments

test: Synchronous test function.
task: Asynchronous function to call repeatedly.
...: Arguments to pass to task.

Value

Deferred value, that is resolved when the iteration is done.

See also

Other async control flow: async_backoff(), async_reflect(), async_retry(), async_retryable(), async_sequence(), async_try_each(), async_whilst()

Examples

## Keep calling until it "returns" a number less than < 0.1
calls <- 0
number <- Inf
synchronise(async_until(
  function() number < 0.1,
  function() {
    calls <<- calls + 1
    number <<- runif(1)
  }
))
#> [1] 0.06521611
calls
#> [1] 10