Fold function in Swift

Fold.swift

func foldl<T, E>(list:Array<T>, base:E, transform:(acc:E, item:T) -> E) -> E {
    var result = base
    for item in list {
        result = transform(acc: result, item: item)
    }
    return result
}

func add(x:Int, y:Int) -> Int {
    return x + y;
}

var numbers = [1,2,3,4,5]
var sum = foldl(numbers, 0, add)

println(sum)

(swift) [1,2,3].reduce(0, +)
// r0 : Int = 6