Decorators

I just wanted to propose that decorators are resolved like this:

```
@{decorator}
def {func_name}({args}):
    {code}
```
to 
```
let {func_name} = {decorator}(|| {
   {code}
})
```
Unfortunately, I am not used to Rust, so this might be totally wrong, but I saw that decorators weren't implemented yet and thought this might be a simple improvement
