Control Flow

if

if priority == "P0" {
    return "incident-lead"
}
return "support"

Boolean operators:

if queue == "platform" and text.contains("timeout") {
    return "incident"
}

for

for ticket in tickets {
    println(ticket["id"])
}

while

let i = 0
while i < 10 {
    println(i)
    i = i + 1
}

match

match result {
    Ok(value) => println(value),
    Err(error) => println("failed: {error}"),
}

stream and yield

Alef supports streaming values lazily using stream and yield. A stream expression creates a lazy iterator that can be evaluated over time.

fn fibonacci(): stream {
    let a = 0;
    let b = 1;
    stream {
        yield a;
        let next = a + b;
        a = b;
        b = next;
    }
}

Use for to consume a stream:

for num in fibonacci() {
    if num > 100 {
        break;
    }
    println(num);
}