It depends on your toolbox. FP (Haskell-FP anyway) appears at first to hobble a lot of mutable algorithms, but (a) it has its own toolbox which has its own stre

It depends on your toolbox. FP (Haskell-FP anyway) appears at first to hobble a lot of mutable algorithms, but (a) it has its own toolbox which has its own strengths and (b) you can embed mutability in such a way to use all of your standard mutable algorithms just the same. From a personal perspective, I program a lot in Haskell and I find it perfectly fluent. Just don't expect to take an algorithm predicted on assumptions of a particular memory model and translate it unmodified without at least using the embedding trick I mentioned above. --- Fortunately, you're in luck. The whole point of this series is to culminate in a description of the "embedding trick" I referenced above. Part 2 is written and being edited now. It introduces a slow, simple, buggy way of writing Union/Find "purely". Part 3 will fix the bug and then explore a fast embedding trick.