On Nov 6, 2017, at 13:10, Andreas Schwab wrote: > On Nov 06 2017, Ken Raeburn > wrote: > >> On Nov 6, 2017, at 09:40, Drew Adams wrote: >> >>>>>> We should perhaps put something about throwing error on '&option &rest' >>>>>> into NEWS though. >>>>> >>>>> I don't understand. In Common Lisp it is perfectly correct >>>>> to use both &optional and &rest. >>>> >>>> What's rejected is (&optional &rest other-vars), whereas (&optional >>>> var1 &rest other-vars) is okay. Does CL accept the first form (and if >>>> yes, what does it mean)? I couldn't tell from the page you linked to. >>> >>> CL accepts a single variable after &rest. And there must be >>> a variable after &optional. (&optional foo &rest bar) is OK. >>> >>> (&optional &rest foo) is not OK. >>> (&optional foo &rest bar toto titi) is not OK. >> >> Is this CL in general or a particular CL implementation? The web page you sent the URL for earlier reads like a specification, and from its use of “*” looks to me like it allows the (admittedly useless) form of &optional with no variables. > > clisp accepts it. It appears that the emacs-26 version of defun* is happy with it (the original Lisp code I posted, using &optional &key) as well, as long as I provide the source, or a byte-compiled file from Emacs 25 or 26; it’s the .elc file generated by the older Emacs that’s causing me a problem. The (new?) checks are incompatible with the the old compiled file, even though the Lisp code itself *appears* to be acceptable still.