At 2002-03-11 17:05, Mark Carroll wrote:

...

When I first learned Standard ML, after years of imperative programming, my brain almost hurt for the first few weeks.

For me the difference is that in imperative you tell the computer what to do, whereas in FP you tell the computer what things are.

In FP you tell the computer "how" to do. The "control" is included. The languages where you tell "what" are the logic languages. In logic languages "control" is the hint to optimize things, and they are optional. In FP you tell "how" to do in a sequence independent manner, but you still embed the "control" in it.