Control flow

Vellum gives you tools for controlling the flow of your scripts. Use an if statement, for and while loops to define your logic.

Conditional statements

You can use the if statement to branch your code logic depending on the condition specified in ():

script MyScript {
    fun foo() {
        bar(42)
    }

    fun bar(i: Int) {
        if i < 100 {
            baz()
        } else if i == 100 {
            qux()
        } else {
            // do nothing
        }
    }

    fun baz() {

    }

    fun qux() {

    }
}

Vellum supports the conditional ternary operator ?: that you can use, for example, for conditional variable initialization:

script MyScript {

    fun foo() {
        bar(true)
    }

    fun bar(condition: Bool) {
        var i = condition ? 42 : -1
    }
}

Loops

Use a while loop for loops with arbitrary condition:

script MyScript {

    fun foo() {
        var i = 0
        while i < 10 {
            i += 1
        }
    }
}

Use a for loop to iterate over an array:

script MyScript {

    fun foo(nums: [Int]) {
        // iterate over array of numbers
        for num in nums {
            // do something with num
        }
    }
}

Jump statements

You can use a return statement for early returning from a function:

script MyScript : ObjectReference {

    event onActivate(obj: ObjectReference) {
        if obj != Game.GetPlayer() {
            return
        }

        // do something
    }
}

Inside loops you can use break and continue statements.

• break terminates the nearest enclosing loop
• continue proceeds to the next step of the nearest enclosing loop

script MyScript : ObjectReference {

    fun foo() {
        var i = 0
        while true {
            if i == 10 {
                break
            }
            i += 1
        }
    }

    fun bar(actors: [Actor]) {
        // process array of actors
        for actor in actors {
            // skip none objects
            if actor == none {
                continue
            }
            // do something with valid actor
        }
    }
}