Thanks for pointing all those out.
- That was a mistake. It has been updated, sorry for that.
- Yes, there is optimization going on underneath even when not using memoization. JS engines esp v8 actually uses memoization kinda thing called inline caching to highly optimize function calls (function calls with the same shape). During compilation and execution, the Ignition interpreter collects feedback and the new TurboFan (v8 optimization engine) uses the info to avoid repetitive calls and perform other optimization tricks.
- Yo have the answer already