It's interesting, but here's the easiest way to evaluate if a Lisp/Scheme implementation article is interesting:<p>"Does it parse (2 . 3) vs (2 3) aka (2 3 . nil) correctly?"<p>That little dot which signifies a cons-pair makes implementing Lisp/Scheme oh-so-stupidly-much harder.<p>Suddenly your printing has to go all the way right before it can make decisions. Your recursions suddenly need to be robust against not being a list. etc.