I really dislike the tiny lisp implementation mentioned in the article. Part of the beauty of a real "lisp in lisp" interpreter is that it is meta-circular -- t

I really dislike the tiny lisp implementation mentioned in the article. Part of the beauty of a real "lisp in lisp" interpreter is that it is meta-circular -- that is, the interpreter is able to interpret itself. Using pmatch and some other tricks makes the interpreter shorter but prevents meta-circular evaluation, in which case you could have just defined the lisp interpreter as just being eval.