fn parsePositive(s: String): Int with {Fail, Console} = {
    Console.print("Parsing \"" + s + "\"...")
    if s == "42" then 42 else if s == "100" then 100 else Fail.fail("Invalid number: " + s)
}

fn safeDivide(a: Int, b: Int): Int with {Fail, Console} = {
    Console.print("Dividing " + toString(a) + " by " + toString(b) + "...")
    if b == 0 then Fail.fail("Division by zero") else a / b
}

fn main(): Unit with {Console} = {
    let n1 = run parsePositive("42") with {}
    Console.print("Result: " + toString(n1))
    let n2 = run parsePositive("100") with {}
    Console.print("Result: " + toString(n2))
    let n3 = run safeDivide(100, 4) with {}
    Console.print("Result: " + toString(n3))
}

let output = run main() with {}
