Loops

Rune supports three distinct types of loops for iterating blocks of code: while, repeat, and count.

While Loop

The while loop runs as long as its condition evaluates to a truthy value:

set count = 5
while count > 0 {
    write(count)
    set count = count - 1
}
# prints 5 4 3 2 1

Repeat Loop

The repeat loop runs a block of code a fixed number of times. The loop count expression is evaluated once at the start:

repeat 3 times {
    write("hello")
}
# prints hello hello hello

The count value must evaluate to a number. Fractional values are automatically truncated to integers.

Count Loop

The count loop iterates a loop variable over an inclusive integer range. The increment/decrement step direction is determined automatically based on the range bounds:

# Counting upwards:
count from 1 to 5 as i {
    write(i)
}
# prints 1 2 3 4 5

# Counting downwards:
count from 3 to 1 as n {
    write(n)
}
# prints 3 2 1

The loop variable is scoped exclusively to the body of the loop.

Loop Control: skip and stop

All three loop variants support early iteration skips and loop termination:

• skip — Skips the remainder of the current loop body iteration (similar to continue).
• stop — Exits the loop block immediately (similar to break).

count from 1 to 10 as i {
    if i == 5 {
        skip
    }
    if i == 8 {
        stop
    }
    write(i)
}
# prints 1 2 3 4 6 7