Trying to use a pure functional style inside an imperative environment will just give you the idea that it is a horrible programming style. Pure functional pro

Trying to use a pure functional style inside an imperative environment will just give you the idea that it is a horrible programming style. Pure functional programming is a different enough approach that it requires a whole different eco-system of libraries. Differently-optimizing compilers, to avoid large runtime penalties. And a different mindset. I think the author is talking about acquiring the different mindset, but in a setting where it is just not very practical.