Python style tuples in Lisp

It's easy to extend Lisp to handle python-style tuples. This is all it takes:

(defun |#{-reader| (stream char arg)
   (declare (ignore char arg))
    `(values ,@(read-delimited-list #\} stream t)))

(set-dispatch-macro-character #\# #\{ #'|#{-reader|)
(set-macro-character #\} (get-macro-character #\) nil))

---

It installs a despatching macro in the readtable - so that when the reader encounters the #{ sequence it reads it up to the } terminating character, then splices it into a (values ...) form.


You can do neat things like (setf #{x y z} #{ 1.2 3.0 3.0 }) to do tuple assignment with no further work - it all falls out of the standard behaviour of Common Lisp.


What I'm wondering, now is if it's possible to combine readtable hacks with regular expressions to implement a lexical parser for an entirely different language without leaving Lisp. I guess it is, but I haven't got a project with a use for it. Yet.