By the way, David's request led me to experiment with different looping constructs in PS, and in the process I noticed that the behaviour of DOLIST diverges from its Common Lisp prototype when used with a RESULT-FORM that references the iteration variable. E. g.: (dolist (i '(1 2 3) (foo i)) (foo i)) expands to (function () { for (var i = null, _js_arrvar58 = [1, 2, 3], _js_idx57 = 0; _js_idx57 < _js_arrvar58.length; _js_idx57 += 1) { i = _js_arrvar58[_js_idx57]; foo(i); }; return foo(i); })(); Since JavaScript variables have at least function scope, this effectively evaluates to foo(3), excluding side effects. On the other hand, CLHS entry for DOLIST (§6.2) contains the following clause: dolist (var list-form [result-form]) declaration* {tag | statement}* ... At the time RESULT-FORM is processed, VAR is bound to NIL. Given this project's goal, stated by Vladimir in a recent message, of bringing PS semantically as close as possible to Lisp, this discrepancy is rather unfortunate, so please find attached a patch to remove it. — B. Smilga.