Killa: Addition metafunction

global.add = function(a, ...) {
    var b = { ... }
    var r = a
    if (typeof(a) == 'string') {
        for each (var i, v in ipairs(b)) {
            r = string.add(r, v)
        }
    } else if (typeof(a) == 'number') {
        for each (var i, v in ipairs(b)) {
            r = math.add(r, v)
        }
    } else if (typeof(a) == 'boolean') {
        // boolean + values : returns if at least one element is true
        if (a) { return a }
        for each (var i, v in ipairs(b)) {
            if (v) { return true }
        }
        return a
    } else if (typeof(a) == 'table') {
        r = table.clone(a)
        for each (var i, v in ipairs(b)) {
            table.add(r, v)
        }
    }
    return r
}