edit: have a look to the origin of the lambdatalk's evaluator: http://lambdaway.free.fr/lambdawalks/?view=levithan http://lambdaway.free.fr/lambdawalks/?view=le

edit: have a look to the origin of the lambdatalk's evaluator: http://lambdaway.free.fr/lambdawalks/?view=levithan http://lambdaway.free.fr/lambdawalks/?view=levithan , a single JS line using a single regular expression (regexp) to evaluate nested s-expressions from inside out. I just had to add 9 special forms [lambda, def, if, let, quote, macro, style, script, require] to extend it towards a programming language. I did not know that regular expressions were a bad choice to build an evaluator, so I tried them.