This is not possible in regular Haskell. For one, it isn't obvious how to do such a desugaring and, even if it were, this is pretty gross.

I remember a co-worker finding some weird combination of old extensions which allowed you to do something gross-ish of this form. I've _never_ seen such a thing in real life.

The only practical issue that comes close to this is sometimes trying to figure out _what_ monad a particular `do` block is running with (my mental type inference falls short of the compiler's).