Repeatedly call task, while test returns true — async_whilst • async

Repeatedly call task, while test returns true

async_whilst(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_until()

Examples

## Keep calling while result is bigger than 0.1
calls <- 0
number <- Inf
synchronise(async_whilst(
  function() number >= 0.1,
  function() {
    calls <<- calls + 1
    number <<- runif(1)
  }
))
#> [1] 0.02806097
calls
#> [1] 12