From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Philipp Stephani Newsgroups: gmane.emacs.devel Subject: Re: Arbitrary function: find the number(s) of expected arguments Date: Sat, 19 Mar 2016 17:49:46 +0000 Message-ID: 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> <8360wi8mbo.fsf@gnu.org> <834mc28m3j.fsf@gnu.org> <8337rm8lfc.fsf@gnu.org> <831t768ilf.fsf@gnu.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=089e01184c04cf94b9052e6a7d57 X-Trace: ger.gmane.org 1458409819 31801 80.91.229.3 (19 Mar 2016 17:50:19 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 19 Mar 2016 17:50:19 +0000 (UTC) Cc: michael_heerdegen@web.de, emacs-devel@gnu.org To: Eli Zaretskii Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Mar 19 18:50:13 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 1ahL0k-0005qK-Ca for ged-emacs-devel@m.gmane.org; Sat, 19 Mar 2016 18:50:02 +0100 Original-Received: from localhost ([::1]:49888 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ahL0j-0001y6-K3 for ged-emacs-devel@m.gmane.org; Sat, 19 Mar 2016 13:50:01 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:46760) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ahL0g-0001xW-3R for emacs-devel@gnu.org; Sat, 19 Mar 2016 13:49:59 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ahL0f-00056s-5W for emacs-devel@gnu.org; Sat, 19 Mar 2016 13:49:58 -0400 Original-Received: from mail-lb0-x22c.google.com ([2a00:1450:4010:c04::22c]:35488) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ahL0e-00056l-P0; Sat, 19 Mar 2016 13:49:57 -0400 Original-Received: by mail-lb0-x22c.google.com with SMTP id bc4so105897245lbc.2; Sat, 19 Mar 2016 10:49:56 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=D2mOEIDMFyRQqVHG3POwURaSLlFdx6f7XOqNlPCTyzQ=; b=yKB8q4DRXqDT8qyqfj/wfSapoj05L7JEdNNHnjWv8zIbPn5PXzEha7T91Eape6h0a4 rNjfJwy84iGtWBIAkDW47MpGiB1YJIgBs/+R97oaI7APuI/dIrpGgkFCpRH115fGizaK dFn6kVxJTqUbRLbIP4ct3PManUM/WREEzlXWWNwDMDw7lx0kdRLW1yPuMZnZsXca65At tMEHQc7C4cg79nENOFw/bYVYtF3LAiJsNvt5nk/uHmswCTpa/Yk4yKlxMPkjBdOePkK3 I1qpBDe0Wcr/iE38AGGfsgFf9Jrwqs+P84ptP0Kpj38Z9xPA1XeBslGmkphUJPJ1Te/S 6Leg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=D2mOEIDMFyRQqVHG3POwURaSLlFdx6f7XOqNlPCTyzQ=; b=gmP6TEYe0u6nS4dPxUOOUuH/B9F93HRJCT19k9J7umgVpCoYNHgV+Tvj9Ff/f0HgY0 XFeqVbBMmcjfIZyEgwpTFlgoOR1rwed+HEcivDndun/bf1t8jxTFft/3NDxbGrquVt9Y mwJky0PogcaQZOsIJCOkrBAr6C1BAzSuHImsN9Khcje3TaZwCCBKyqYYvGJmKzwOJquu JYu4FRwDREngCTJf8NfZ2XvyQCRpLQMBO5lr/9gNSyFIktyhEG7kMnajfLz11CfxoKeq R7My/O46dZodZWGN7+2M5hcmqKeUVnBtcBhyh1coU263ed+ZQOjvBxMNuwdqkrAu7r8/ niQA== X-Gm-Message-State: AD7BkJKXBgr39z+Mec1ooAhlPy2Ythj7qbuTxKBm9Z9FWh0UT3dQlcoI0Rj/SvmlNro8wDdfutO6hi2qNCBA/A== X-Received: by 10.112.143.69 with SMTP id sc5mr7898635lbb.64.1458409795718; Sat, 19 Mar 2016 10:49:55 -0700 (PDT) In-Reply-To: <831t768ilf.fsf@gnu.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-Received-From: 2a00:1450:4010:c04::22c 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:201888 Archived-At: --089e01184c04cf94b9052e6a7d57 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Eli Zaretskii schrieb am Sa., 19. M=C3=A4rz 2016 um 18:48 Uh= r: > > From: Philipp Stephani > > Date: Sat, 19 Mar 2016 17:16:55 +0000 > > Cc: michael_heerdegen@web.de, emacs-devel@gnu.org > > > > > We are discussing for which cases it can be implemented. It can be > implemented and would be > > useful for a > > > wide range of functions, such as those defined with defun. It cannot > be implemented for functions like > > g; that's > > > just a limitation we have to live with. > > > > That's one possibility. Another is that the implementation will be > > able to find out the truth, just like the Lisp interpreter does. > > > > Presumably that would imply solving the halting problem. > > I guess we'll have to disagree about that. > You could convince me by posting a generic implementation that would figure out the arity of g without executing it. --089e01184c04cf94b9052e6a7d57 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable


Eli Za= retskii <eliz@gnu.org> schrieb am= Sa., 19. M=C3=A4rz 2016 um 18:48=C2=A0Uhr:
> From: Philipp Stephani <p.stephani2@gmail.com>
> Date: Sat, 19 Mar 2016 17:16:55 +0000
> Cc: mich= ael_heerdegen@web.de, emacs-devel@gnu.org
>
>=C2=A0 > We are discussing for which cases it can be implemented. It= can be implemented and would be
>=C2=A0 useful for a
>=C2=A0 > wide range of functions, such as those defined with defun. = It cannot be implemented for functions like
>=C2=A0 g; that's
>=C2=A0 > just a limitation we have to live with.
>
>=C2=A0 That's one possibility. Another is that the implementation w= ill be
>=C2=A0 able to find out the truth, just like the Lisp interpreter does.=
>
> Presumably that would imply solving the halting problem.

I guess we'll have to disagree about that.

You could convince me by posting a generic implementation that woul= d figure out the arity of g without executing it.=C2=A0
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