Now you have to make `f` nullable and you run the risk of not initialising it and getting a null pointer.

You can't do it in C, but in functional style languages you can do this:

  let f = {
    let bar = ...;
    let baz = ...;
    let barbaz = ...;
    barbaz
  };

Which is a lot nicer. But if you ask me it's just a function by another name except it still doesn't limit scope quite as precisely as a function.