R: Examples for 'R.utils::withTimeout'

### ** Examples

# - - - - - - - - - - - - - - - - - - - - - - - - -
# Function that takes "a long" time to run
# - - - - - - - - - - - - - - - - - - - - - - - - -
foo <- function() {
  print("Tic")
  for (kk in 1:100) {
    print(kk)
    Sys.sleep(0.1)
  }
  print("Tac")
}


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# Evaluate code, if it takes too long, generate
# a timeout by throwing a TimeoutException.
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res <- NULL
tryCatch({
  res <- withTimeout({
    foo()
  }, timeout = 1.08)
}, TimeoutException = function(ex) {
  message("Timeout. Skipping.")
})

[1] "Tic"
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
[1] 6
[1] 7
[1] 8
[1] 9
[1] 10
[1] 11

Timeout. Skipping.

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# Evaluate code, if it takes too long, generate
# a timeout returning NULL and generate a warning.
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res <- withTimeout({
  foo()
}, timeout = 1.08, onTimeout = "warning")

[1] "Tic"
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
[1] 6
[1] 7
[1] 8
[1] 9
[1] 10
[1] 11
[1] 12
[1] 13

Warning in value[[3L]](cond): reached elapsed time limit [cpu=1.08s,
elapsed=1.08s]

# The same using an expression object
expr <- quote(foo())
res <- withTimeout(expr, substitute = FALSE,
                   timeout = 1.08, onTimeout = "warning")

[1] "Tic"
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
[1] 6
[1] 7
[1] 8
[1] 9
[1] 10
[1] 11

Warning in value[[3L]](cond): reached elapsed time limit [cpu=1.08s,
elapsed=1.08s]

# - - - - - - - - - - - - - - - - - - - - - - - - -
# Evaluate code, if it takes too long, generate
# a timeout, and return silently NULL.
# - - - - - - - - - - - - - - - - - - - - - - - - -
res <- withTimeout({
  foo()
}, timeout = 1.08, onTimeout = "silent")

[1] "Tic"
[1] 1
[1] 2
[1] 3
[1] 4
[1] 5
[1] 6
[1] 7
[1] 8
[1] 9
[1] 10
[1] 11

Examples for 'R.utils::withTimeout'

Evaluate an R expression and interrupts it if it takes too long