Actually, that was one of his major points in the lecture that I referenced. Basically, you should start with measurements and go from there. He said that he pe

Actually, that was one of his major points in the lecture that I referenced. Basically, you should start with measurements and go from there. He said that he personally uses FP quite a bit, so he wasn't a hater per se...except for FP fan boys. He did go on about that quite a bit. The main thing that he stressed about data structures was that memory layout matters in that hardware has a lot of built in intelligence for accelerating memory access patterns that it can discern. The way that immutable data structures are created, updated, and destroyed don't produce a suitably detectable memory access pattern, apparently. His explanation was detailed and is worth watching. That being said he wasn't proposing "share state for all". He was mainly proposing the scientific method.