From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Arbitrary function: find the number(s) of expected arguments Date: Sat, 19 Mar 2016 18:24:03 +0200 Message-ID: <837fgy8mho.fsf@gnu.org> References: <56E8906C.5050405@lanl.gov> <83egb68vfy.fsf@gnu.org> <87zituefp9.fsf@web.de> <83a8lu8srs.fsf@gnu.org> <87twk2ebp2.fsf@web.de> <838u1e8od1.fsf@gnu.org> <87pouqe9yw.fsf@web.de> Reply-To: Eli Zaretskii NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1458404688 19566 80.91.229.3 (19 Mar 2016 16:24:48 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 19 Mar 2016 16:24:48 +0000 (UTC) Cc: emacs-devel@gnu.org To: Michael Heerdegen Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Mar 19 17:24:43 2016 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ahJgB-0003y6-HF for ged-emacs-devel@m.gmane.org; Sat, 19 Mar 2016 17:24:43 +0100 Original-Received: from localhost ([::1]:49574 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ahJg7-0008NC-K2 for ged-emacs-devel@m.gmane.org; Sat, 19 Mar 2016 12:24:39 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:54144) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ahJg3-0008N3-J1 for emacs-devel@gnu.org; Sat, 19 Mar 2016 12:24:36 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ahJfz-0007kR-JS for emacs-devel@gnu.org; Sat, 19 Mar 2016 12:24:35 -0400 Original-Received: from fencepost.gnu.org ([2001:4830:134:3::e]:59004) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ahJfz-0007kN-GU; Sat, 19 Mar 2016 12:24:31 -0400 Original-Received: from 84.94.185.246.cable.012.net.il ([84.94.185.246]:3868 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1ahJfy-0007AV-Pi; Sat, 19 Mar 2016 12:24:31 -0400 In-reply-to: <87pouqe9yw.fsf@web.de> (message from Michael Heerdegen on Sat, 19 Mar 2016 16:57:59 +0100) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2001:4830:134:3::e X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:201873 Archived-At: > From: Michael Heerdegen > Date: Sat, 19 Mar 2016 16:57:59 +0100 > > So what should `function-arity' return? The actual arity of the > function? An arity that takes information about some known kinds of > wrappers into account? It should returns information about the number of arguments with which the function can be called right after the call to function-arity. > No matter how you do it: the result will never give you a clear answer. I disagree with this conclusion. The fact is that the Emacs Lisp interpreter does know how to produce a clear answer. > Even if the user understands what he is doing: if `function-arity' can't > answer the question whether a certain number of arguments is allowed, it > is of not much value. I think it can, and it will be.