From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Noam Postavsky Newsgroups: gmane.emacs.devel Subject: Lisp watchpoints (Was: [Emacs-diffs] master 19e09cf: Ensure redisplay after evaluation) Date: Sat, 14 Nov 2015 13:14:15 -0500 Message-ID: NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: ger.gmane.org 1447585309 11901 80.91.229.3 (15 Nov 2015 11:01:49 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 15 Nov 2015 11:01:49 +0000 (UTC) Cc: John Wiegley , Eli Zaretskii , emacs-devel@gnu.org To: Stefan Monnier Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sun Nov 15 12:01:48 2015 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 1Zxv47-0007XK-5b for ged-emacs-devel@m.gmane.org; Sun, 15 Nov 2015 12:01:47 +0100 Original-Received: from localhost ([::1]:41870 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zxv46-0003QX-D3 for ged-emacs-devel@m.gmane.org; Sun, 15 Nov 2015 06:01:46 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:58994) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZxfL8-0006kh-GI for emacs-devel@gnu.org; Sat, 14 Nov 2015 13:14:19 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZxfL7-0007Xa-H1 for emacs-devel@gnu.org; Sat, 14 Nov 2015 13:14:18 -0500 Original-Received: from mail-io0-x232.google.com ([2607:f8b0:4001:c06::232]:34325) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZxfL5-0007X9-Vn; Sat, 14 Nov 2015 13:14:16 -0500 Original-Received: by ioir85 with SMTP id r85so85320136ioi.1; Sat, 14 Nov 2015 10:14:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:date:message-id:subject:from:to:cc:content-type; bh=LoDL01H2EZgiMGrPkmXsGUNdASEz6i80ozMwxoD9xys=; b=x/Km66qttygiwZRd08ajYKil29bTdTEHxTHWPJeFtYwH5EUIHY27/P9MZV1cSZlLdP tPgJzVNilvcSXnKTzI4dOcfkeyJqKO/Ok0jpfKJS8QQvuOjfYeJmq0nWgKjO5dDeLo9b RFTQpPdnjxmmeK4N4yK3IoL4zNgQlHNjZKgbpjAPx280xzW5Ikwls4ZyPEfdMi8ZfvCX Q9FMfbNncBIUyldbh3VJOnrxdZZiC4pIFomWLWb9o82s0tHLomcFPclQ1AIRX5tc36hL 4rK4ZDUT+4DkkctOua5SHl47CnduWj9p3alub0KLXXEfvgCncac3kBMzWtV/NmTXwson lxqw== X-Received: by 10.107.130.167 with SMTP id m39mr26725112ioi.18.1447524855300; Sat, 14 Nov 2015 10:14:15 -0800 (PST) Original-Received: by 10.79.119.2 with HTTP; Sat, 14 Nov 2015 10:14:15 -0800 (PST) X-Google-Sender-Auth: rBM84bzmThhJF2XK1GOF2cYgTsg X-detected-operating-system: by eggs.gnu.org: Error: Malformed IPv6 address (bad octet value). X-Received-From: 2607:f8b0:4001:c06::232 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:194486 Archived-At: On Fri, Nov 13, 2015 at 8:58 AM, Stefan Monnier wrote: > Actually, I think it's not that complicated: > - Look at the definition of SYMBOL_CONSTANT_P. There is a comment on Lisp_Symbol's `constant' field saying "If the value is 3, then the var can be changed, but only by `defconst'". However, I can't find any code that uses this value. Is it safe to ignore? > - Change its name to SYMBOL_SLOWWRITE_P. > - Change the field it tests from being a boolean to being a 3-valued > thingy, with values "fullspeed", "hooked", and "readonly". Would it be sensible to implement "readonly" as "hooked" + some hook that signals error on write? > Maybe it'd be nice to make sure that "defvaralias" could be > re-implemented on top of those hooks, even though I don't think such > a reimplementation is desirable at this point. To do that we'd have to trap reads as well as writes, right? Which could be useful for debugging too.