From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Michael Heerdegen Newsgroups: gmane.emacs.devel Subject: Re: [Emacs-diffs] master 4612b2a 1/2: Implement and-let* Date: Thu, 14 Sep 2017 17:46:45 +0200 Message-ID: <87y3phcmfu.fsf@web.de> References: <20170912171813.26498.77867@vcs0.savannah.gnu.org> <20170912171815.13B9520DE6@vcs0.savannah.gnu.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1505404086 17434 195.159.176.226 (14 Sep 2017 15:48:06 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 14 Sep 2017 15:48:06 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.0.50 (gnu/linux) Cc: mvoteiza@udel.edu, Stefan Monnier , emacs-devel@gnu.org To: Richard Stallman Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Thu Sep 14 17:48:01 2017 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dsWMz-0004RN-DU for ged-emacs-devel@m.gmane.org; Thu, 14 Sep 2017 17:48:01 +0200 Original-Received: from localhost ([::1]:48542 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dsWN6-0002XV-UB for ged-emacs-devel@m.gmane.org; Thu, 14 Sep 2017 11:48:08 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:57023) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dsWM0-0001xR-Ql for emacs-devel@gnu.org; Thu, 14 Sep 2017 11:47:01 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dsWLv-0005OK-V9 for emacs-devel@gnu.org; Thu, 14 Sep 2017 11:47:00 -0400 Original-Received: from mout.web.de ([212.227.17.12]:58513) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dsWLv-0005Ml-LT; Thu, 14 Sep 2017 11:46:55 -0400 Original-Received: from drachen.dragon ([213.240.83.169]) by smtp.web.de (mrweb102 [213.165.67.124]) with ESMTPSA (Nemesis) id 0LjJL9-1dHooy2FUV-00dWZf; Thu, 14 Sep 2017 17:46:47 +0200 In-Reply-To: (Richard Stallman's message of "Wed, 13 Sep 2017 12:39:47 -0400") X-Provags-ID: V03:K0:QsWc4XiMWILzhxW80KP36bOq6gjkSwQA7gTFoOLSsFcvLournGv SB6ghUxGSOjoWL5sXsUUrpLhdmNAu2SDGmskER4Q2BXBG5HrAnfiP2G7NDZOBw63DDlK/zR 5hGTSNvgSZV392Ci/Sie3xPQOXZxIPariCSDvCxq8+6gZ4f1mG0hHQ3SWy1fnEU5HHIEBHH kEYeK6rU0nKM1JHzLeaxg== X-UI-Out-Filterresults: notjunk:1;V01:K0:i/tzVq4uGG4=:SdqXWut4p1TKEfkrRH9WFO iRVVf0iEoN71ZB6CVEV6SAR/I8VScOVAxuCJrHfum9u54DlNBhiG1skRmrw/ZCUtFoDmLKe8l CRbiWo2DB0rFJpGaqu+8OLbyvcD1X6LXzRCw1vQHTbjEyjB/B5NfgXXvzDjjlOHBpKlpdP3Oe Xzq62PaaQCmhccVMLjhzxGIAixsfOp3i6h1Lpqaw2Rn8jh+9NUOHgawUds5+m3VTGRZE+ED+t xjBGhei7fF5CnmJ13iAEIQx+WFEfLKMBSyTidABUs6DUvxrTtHE+UzGt2lSKy0IuudqOLp7h+ UCOsJ+5CtdN5bH9OgVBZVPEmwoSM6fp27lqJ21NYGE9BG11Dx3FW83IqANjNki0dfTXAW+yyS ZxK1KYs4qyOEpxZgbLyPP4LiwGRQrhot7g9UHP/TzDY14NLkEXp9ahX0uJSgsfTBtq0QGQFEJ kD50FGyqymMnmVBAz4ysnZQxL6Q1twq0qnE134ShSpVwXi1k3iWWk82KnZr8S61/owe8Zx7G1 xMvKewH8ANxMt4URsAmgamRu5oymH7Uj72Lknc9ohSpMe7WZn/qaQjzixqVPfM/OyBc+L4T9a 1sO3ilQKD8/OBOPG4TMVT8sX6Ts1QeEKefgnWeY4elK/hoMjqz0zEDFHm6FYmpCJ8rTy9lr/t jd8FdEoCcunw/d4gOx4UZMGbPFrWvdBK+nGbXQCCsOAWLkpizY0fG7I6aLfNgrInHKhnNrSdG 0F5VjTDKurd/Ww0nRUF4y3pjGpaRX8vTv/2DPC/MlyIC+Yc/JYNEZL/X5qF3rDdC6TU3SnWR X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 212.227.17.12 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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" Xref: news.gmane.org gmane.emacs.devel:218273 Archived-At: Richard Stallman writes: > > > (internal--build-binding-value-form): Extend to account for > > > solitary symbols and (EXPR) items in binding varlist. > > > We're forced to accept those forms in `let` and `let*` for historical > > reasons, > > It is not just a matter of history. > Those are very convenient in 'let'. > It would be a bad idea not to have them. > Whether they are useful in other new constructs, I don't know. > What do these new constructs look like? Just search for SRFI 2, e.g. https://www.gnu.org/software/guile/manual/html_node/SRFI_002d2.html `if-let*' and `when-let*' in Emacs are analogue. I don't know much about Lisp's history, but I think there was a misunderstanding about what these special binding forms mean. For example, making a binding form consisting of a single symbol mean "bind the symbol to nil" would not make sense in these new constructs - instead, we test the symbol's value for nilness. Michael.