Paul Rubin wrote: > Alexander Schmolck <[EMAIL PROTECTED]> writes: > >>> (defvar *x*) ;; makes it special >>> (setf *x* 1) >>> (print *x*) ;;-> 1 >>> (let ((*x* 2)) >>> (print *x*)) ;; -> 2 >>> (print *x*) ;; -> 1 >> >>You seem to think that conflating special variable binding and lexical >>variable binding is a feature and not a bug. What's your rationale? > > > I thought special variables meant dynamic binding, i.e. > > (defvar *x* 1) > (defun f () > (print *x*) ;; -> 2 > (let ((*x* 3)) > (g))) > (defun g () > (print *x*)) ;; - > 3 > > That was normal behavior in most Lisps before Scheme popularlized > lexical binding. IMO it was mostly an implementation convenience hack > since it was implemented with a very efficient shallow binding cell. > That Common Lisp adapted Scheme's lexical bindings was considered a > big sign of CL's couthness. So I'm a little confused about what Ken > Tilton is getting at.
Paul, there is no conflict between your example and mine, but I can see why you think mine does not demonstrate dynamic binding: I did not demonstrate the binding applying across a function call. What might be even more entertaining would be a nested dynamic binding with the same function called at different levels and before and after each binding. I just had the sense that this chat was between folks who fully grokked special vars. Sorr if I threw you a curve. kenny -- http://mail.python.org/mailman/listinfo/python-list
