[OT] Interesting blog post on disadvantages of the pure functional paradigm

[Kagamin via Digitalmars-d]

Functional doesn't imply purity and immutability, and mutable 
functional has cognitive problems: mutation is important, but 
functional code is too high level, so whatever happens is hidden 
from the programmer; D suffers from this too as people are 
confused whether ranges are taken by value or by reference - this 
is important because they are mutable.