gistfile1.txt

var axisHandlerPerIndex = func(pre, post) {
    func(idx = 0) {
        var val = cmdarg().getNode("setting").getValue();
        setprop(pre ~ idx ~ post, (1 - val) / 2);
    }
}

var throttleAxisPerEngine = axisHandlerPerIndex("/controls/engines/engine[", "]/throttle");