R While Loops

How it works

while repeats while its scalar condition is true. Something in the body must make progress towards stopping, or the loop needs an explicit limit. This example processes a fixed pending count with a separate maximum-steps guard. It performs no network request or real queue mutation.

Run this R example

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Example

local({
  previous_options <- options(warn = 2, digits = 8, stringsAsFactors = FALSE)
  on.exit(options(previous_options), add = TRUE)
  pending <- 3L
  handled <- 0L
  while (pending > 0L && handled < 10L) {
    pending <- pending - 1L
    handled <- handled + 1L
  }
  cat("handled:", handled, "pending:", pending, "\n")
  invisible(NULL)
})

pending <- 3L
handled <- 0L
while (pending > 0L && handled < 10L) {
  pending <- pending - 1L
  handled <- handled + 1L
}
cat("handled:", handled, "pending:", pending, "\n")

Expected result

handled: 3 pending: 0

The pending value decreases every iteration, and handled limits the work even if a later edit damages the progress rule. Both conditions are scalar. In a real external polling loop you would also need a timeout and an explicit failure result.