use std/io use std/vec.Vec struct Counter { value: i32 } blocking func main(): i32! { var counters = Vec [Counter { value: 1 }, Counter { value: 2 }, Counter { value: 3 }] for counter in &+counters { counter.value += 10 } var borrowed_total: i32 = 0 for counter in &counters { borrowed_total += counter.value } var moved_total: i32 = 0 for counter in move counters { moved_total += counter.value } let message = "borrowed: ${borrowed_total}, moved: ${moved_total}\n" io.print(&message)? return 0 }

func main(): i32 { let value = load_value() catch failure { fallback_for(failure.message()) } if value == 42 { return 0 } return 1 } func load_value(): i32! { return error.new("example.unavailable", "the primary value is unavailable") } func fallback_for(message: &str): i32 { return 42 }

use std/task use std/time use std/time.Duration async func delayed(value: i32): i32 { await time.sleep(Duration.from_milliseconds(1)) return value } async func main(): i32! { let (left, right) = await task.join(delayed(20), delayed(22)) if left + right != 42 { return error.new("example.unexpected_total", "joined tasks returned the wrong total") } return 0 }

use std/io use std/url.Url blocking func main(): i32! { let url = Url.parse("HTTP://Example.COM:80/a/../status?q=ready#fragment")? let canonical = url.to_string() let authority = url.authority() let target = url.request_target() io.println(&canonical)? io.println(&authority)? io.println(&target)? return 0 }

mutable-iteration.nct

use std/io
use std/vec.Vec

struct Counter {
    value: i32
}

blocking func main(): i32! {
    var counters = Vec [Counter { value: 1 }, Counter { value: 2 }, Counter { value: 3 }]
    var expected: i32 = 11
    for counter in &+counters {
        counter.value += 10
        if counter.value != expected {
            return 1
        }
        expected += 1
    }
    var readonly_total: i32 = 0
    for counter in &counters {
        readonly_total += counter.value
    }
    if readonly_total != 36 {
        return 1
    }
    var owned_total: i32 = 0
    for counter in move counters {
        owned_total += counter.value
    }
    if owned_total != 36 {
        return 1
    }
    io.print("mutable iteration updated every element\n")?
    return 0
}