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?The compiler runs in this tab as WebAssembly, and so does the program it compiles. Nothing is uploaded. A program is stopped after five seconds, and a recursion that outgrows the tab's stack stops with the error vyrn run gives. The tab has no filesystem and no arguments. One file runs, plus std/, which is built in.Loading the compiler… 0Ln 1, Col 1Spaces: 2UTF-8VyrnShift+F10 Run

fn main() -> Int64 {
    print("hello")
    return 0
}

type Age = Int64 where value >= 18

fn admit(n: Int64) -> Int64 {
    // `Age?(n)` is None when the rule fails, so untrusted input never traps.
    return match Age?(n) {
        Some(a) => a,
        None => 0 - 1,
    }
}

fn main() -> Int64 {
    print(admit(30))
    print(admit(5))
    // Uncomment the next line. The compiler refuses it, and says why.
    // let bad = Age(5)
    return 0
}

type Ticket = { id: Int64, seats: Int64 }

fn seatCount(t: read Ticket) -> Int64 { return t.seats }
fn addSeat(t: modify Ticket) { t.seats = t.seats + 1 }
fn redeem(t: consume Ticket) -> Int64 { return t.id }

fn main() -> Int64 {
    let mut t = Ticket { id: 7, seats: 2 }
    print(seatCount(t))
    addSeat(t)
    print(seatCount(t))
    print(redeem(t))
    // `t` was consumed above. Name it again and the compiler refuses:
    // print(seatCount(t))
    return 0
}

fn fib(n: Int64) -> Int64 {
    if n < 2 { return n }
    return fib(n - 1) + fib(n - 2)
}

fn main() -> Int64 {
    let mut i = 0
    while i <= 15 {
        print(fib(i))
        i = i + 1
    }
    return 0
}

// The lines in the standard input box below arrive here, one per call.
// At the end of them `readLine()` answers None, exactly as a pipe does.
fn main() -> Int64 {
    let mut n = 0
    while let Some(line) = readLine() {
        print("\{n}: \{line}")
        n = n + 1
    }
    print("\{n} line(s)")
    return 0
}

// A trap writes to standard error and the program exits non-zero — the same
// channels a terminal gives it.
fn main() -> Int64 {
    print("before")
    panic("this is a trap")
    return 0
}

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