 <p>This is outside of the language specification and I think if this is a feature that you wish to have in the language another language would be of more use to you that has this kind of functionality in it. </p> <p>The only way I can think of implementing this is by doing some preprocessing tricks, which just seems like a bad idea. With this method you will not have if's in the code it self but some very unmaintainable preprocessing.</p>