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sleep

sleep(num) -> null

What it does

Waits that many milliseconds, then gives null. Other requests run meanwhile: the wait does not hold the server. There is no maximum. In a scheduled job or a tick the wait ends early when the server stops or the program is loaded again, so a loop that runs for ever stops; a request waits its sleep out. It is an effect, like random() and read_file.

Examples

let before = now()let r = sleep(5)print(r, now() - before >= 5)

null true

Edge cases

• Zero is fine and returns at once; a float is allowed, cut to whole milliseconds.
• It takes milliseconds, not seconds as Python's time.sleep does. quillo check warns of a number literal between 0 and 1, which waits less than a millisecond: sleep(0.2) gives warning: `sleep` takes milliseconds: `sleep(0.2)` waits 0.2 ms; for 0.2 seconds write `sleep(200)` . sleep(0), sleep(1) and a variable are not warned of.
• It returns null, so it ends an expression-bodied function with null; put it before the value you mean.
• In a job or a tick a server stopping or a reload ends the job there with a 503, as a reply would, instead of letting it run on old code.
• A request's sleep of 5 ms or more waits on a timer and holds no thread, so a hundred streams sleeping in their loops hold up no other request; a shorter one waits on a thread, for its accuracy (a timer's are whole milliseconds).
• In a parallel function, a sleep ends at once when another of the functions fails.

print(sleep(0), sleep(1.5))fn wait_then(v) {    sleep(1)    v}print(wait_then("done"))

null nulldone

Errors

A negative number, or anything that is not a number, is a runtime error, not an error value.

print(sleep(-1))

line 1: `sleep` expects milliseconds (a number >= 0), got int

print(sleep("5"))

line 1: `sleep` expects milliseconds (a number >= 0), got str

Chaining

It is rarely piped; in a loop it paces work, and in a tick it is what makes the tick slow:

let t = now()for i in range(0, 3) { sleep(2) }print(now() - t >= 6)

true

schedule("every 1m", () => {    for job in pending() {        run(job)        sleep(200)    }})

See also

now, schedule, every, parallel

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