I've been paying attention to functional for the last 6 or so months and coming from a C background, its emphasis on immutability, data-oriented, readability, and safeness is really attractive if you're not worried about performance (which is allowed to take a back seat in most apps these days). I can't wait for software to be improved harboring the benefits of functional programming.

Why should FP be slower ?

The articles emphasises that one of the main arguments in favour of FP is that it's easy to see what part of the recipe can be done in parallel. Why can't the runtime automatically leverage multiple cores and speed up the process ?

To sum it up, it's a kind of chicken-and-egg. Imperative/OO is tied to the physical implementation of processors, whereas FP is tied to a mathematical construct for which conventional CPUs are not optimized.

Related:

https://github.com/tommythorn/Reduceron

https://stackoverflow.com/questions/15005670/why-is-there-no...