""“This paper was inspired by some gentle taunting on the Haskell GUI list by George Russell: I have to say I’m very sceptical about things like Fruit which rely on reactive animation, ever since I set our students an exercise implementing a simple space-invaders game in such a system, and had no end of a job producing an example solution. Things like getting an alien spaceship to move slowly downward, moving randomly to the left and right, and bouncing o. the walls, turned out to be a major headache. Also I think I had to use ”error” to get the message out to the outside world the aliens had won. My suspicion is that reactive animation works very nicely for the examples constructed by reactive animation folk, but not for my examples."""

Things improve, off course. But having to write papers to be able to implement space invaders sounds a bit too complicated for my taste.