From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: "Stephen J. Turnbull" Newsgroups: gmane.emacs.devel Subject: RFC: make maphash return a list Date: Sat, 04 May 2013 14:29:02 +0900 Message-ID: <87txmjcnz5.fsf@uwakimon.sk.tsukuba.ac.jp> References: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 X-Trace: ger.gmane.org 1367645357 5194 80.91.229.3 (4 May 2013 05:29:17 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 4 May 2013 05:29:17 +0000 (UTC) Cc: emacs-devel@gnu.org To: Wilfred Hughes Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat May 04 07:29:15 2013 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 1UYV23-00024I-Ds for ged-emacs-devel@m.gmane.org; Sat, 04 May 2013 07:29:15 +0200 Original-Received: from localhost ([::1]:37671 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UYV23-0001YI-1W for ged-emacs-devel@m.gmane.org; Sat, 04 May 2013 01:29:15 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:41998) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UYV1z-0001YD-OF for emacs-devel@gnu.org; Sat, 04 May 2013 01:29:12 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1UYV1y-0007mU-Vg for emacs-devel@gnu.org; Sat, 04 May 2013 01:29:11 -0400 Original-Received: from mgmt2.sk.tsukuba.ac.jp ([130.158.97.224]:35571) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1UYV1y-0007l5-IK for emacs-devel@gnu.org; Sat, 04 May 2013 01:29:10 -0400 Original-Received: from uwakimon.sk.tsukuba.ac.jp (uwakimon.sk.tsukuba.ac.jp [130.158.99.156]) by mgmt2.sk.tsukuba.ac.jp (Postfix) with ESMTP id 61637970944; Sat, 4 May 2013 14:29:02 +0900 (JST) Original-Received: by uwakimon.sk.tsukuba.ac.jp (Postfix, from userid 1000) id 257531A4D34; Sat, 4 May 2013 14:29:02 +0900 (JST) In-Reply-To: X-Mailer: VM undefined under 21.5 (beta32) "habanero" b0d40183ac79 XEmacs Lucid (x86_64-unknown-linux) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6.x X-Received-From: 130.158.97.224 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:159283 Archived-At: Wilfred Hughes writes: > I've been using Emacs hash tables a lot recently, and I would find > several operations much easier if maphash returned a list. For > example, I'd like to be able to do: > > (maphash (lambda (key value) key) some-table) (defun choose-name-to-taste (callable table) "Left as an exercise for the reader." (let ((retlist nil)) (maphash (lambda (key value) (setq retlist (cons (funcall callable key value) retlist))) table)) retlist)) > Is there interest in this? Please don't, for the reasons given in other replies. > However, unlike elisp, Common Lisp's loop macro supports iterating > over keys directly with (loop for key being hash-key of some-table > ...) which helps considerably. Isn't this the right place to improve elisp?