I'm in a function, I'm doing a lot of function things, maybe even in just a few lines of code, and I want to return the result of some expression or another. Do I get to see the result of my expression before I return from the function? NO. Unless I assign it to some local, I can't.
As you can see, this is a very desired feature. Implement it, and I will throw money at you and get others to do the same.
Customer support service by UserEcho