Re: Unary /

[David Kastrup <dak@gnu.org>]

Tassilo Horn <tsdh@gnu.org> writes:

> "Stephen J. Turnbull" <stephen@xemacs.org> writes:
>
>>  > In Elisp, (/ 2.0) returns 2.0.  In Common Lisp
>>  > <URL:http://www.lispworks.com/documentation/lw50/CLHS/Body/f_sl.htm>
>>  > (and in Scheme), this returns 0.5.
>>
>> Also in XEmacs (/ 2.0) => 0.5.  Just a bug in Emacs, I bet.  So I
>> guess the Common Lisp behavior isn't particularly useful, either or
>> somebody would have reported sooner. :-)
>
> Before Fri Nov 9 17:20:47 2012 -0500, / required at least two arguments
> in Emacs.

Ah, so there will not be a lot of legacy code relying on the current
semantics.  This would be

commit 32e5c58ca969ec30d31520da52c9866cafa62927
Author: Stefan Monnier <monnier@iro.umontreal.ca>
Date:   Fri Nov 9 17:20:47 2012 -0500

    Provide new `defalias-fset-function' symbol property.
    * src/lisp.h (AUTOLOADP): New macro.
    * src/eval.c (Fautoload): Don't attach to loadhist, call Fdefalias instead.
    * src/data.c (Ffset): Remove special ad-advice-info handling.
    (Fdefalias): Handle autoload definitions and new Qdefalias_fset_function.
    (Fsubr_arity): CSE.
    (Finteractive_form): Simplify.
    (Fquo): Don't insist on having at least 2 arguments.
    (Qdefalias_fset_function): New var.
    * lisp/emacs-lisp/advice.el (ad-set-advice-info): Set defalias-fset-function.
    (ad--defalias-fset): New function.
    (ad-safe-fset): Remove.
    (ad-make-freeze-definition): Use cl-letf*.

Since there are about a dozen apparently unrelated changes, the question
is whether anything specifically relied on this change.

Stefan, any insights?

-- 
David Kastrup