From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Newsgroups: gmane.emacs.help Subject: Re: How to tame compiler? Date: Sun, 2 May 2021 11:06:47 +0200 Message-ID: <20210502090647.GB9577@tuxteam.de> References: <875z03th9b.fsf@web.de> <87v981wv3f.fsf@web.de> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="wzJLGUyc3ArbnUjN" Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="25073"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mutt/1.5.21 (2010-09-15) To: Michael Heerdegen , help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sun May 02 11:08:41 2021 Return-path: Envelope-to: geh-help-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1ld85g-0006P7-Tx for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 02 May 2021 11:08:40 +0200 Original-Received: from localhost ([::1]:40754 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1ld85g-00070R-0P for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 02 May 2021 05:08:40 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:37984) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1ld846-00070L-HF for help-gnu-emacs@gnu.org; Sun, 02 May 2021 05:07:02 -0400 Original-Received: from mail.tuxteam.de ([5.199.139.25]:40819) by eggs.gnu.org with esmtps (TLS1.2:DHE_RSA_AES_128_CBC_SHA1:128) (Exim 4.90_1) (envelope-from ) id 1ld840-0005Yp-NH for help-gnu-emacs@gnu.org; Sun, 02 May 2021 05:07:02 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=tuxteam.de; s=mail; h=From:In-Reply-To:Content-Type:MIME-Version:References:Message-ID:Subject:To:Date; bh=JdpMOEE6A/8Ursr0hmaVhRlZJ0iSZlA85F3t7joqZp0=; b=X2JiOOUvrRuEI9fkv6v2gYgMlHayZqEYhWpnOq7hwjgHLuqDFCZ97A6OlikbvHj01S7AR0MUiO09BFhSl189hc+Wj/jGrbPXoxkRrf8ucXz1BsdUzzQY+btOLGY+UUQ8jOIxtZJOxhoTS8lAQnNqCJSGMMNsVeepoxs7EsheheFkiO8GDRJUOgFT9BmLg1TEI7H87VTTpUGdEDetl+Tc8xR61nMNVpl+Fn1MR4FYL+iJfWzXcatg/cLcBYwVDx78n7592FAoXyqWLZEduQy3OI4hwk19APewT8CTXgQ1ktstEcxajfpV0SYHESDy9BKYqZ42H2cW6QHmydN1yRknfA==; Original-Received: from tomas by mail.tuxteam.de with local (Exim 4.80) (envelope-from ) id 1ld83r-0003WO-Oi; Sun, 02 May 2021 11:06:47 +0200 Content-Disposition: inline In-Reply-To: Received-SPF: pass client-ip=5.199.139.25; envelope-from=tomas@tuxteam.de; helo=mail.tuxteam.de X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Users list for the GNU Emacs text editor List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "help-gnu-emacs" Xref: news.gmane.io gmane.emacs.help:129317 Archived-At: --wzJLGUyc3ArbnUjN Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Sun, May 02, 2021 at 10:45:10AM +0300, Jean Louis wrote: > * Michael Heerdegen [2021-05-02 08:43]: > > Stefan Monnier writes: > >=20 > > > I know I sound like a broken clock, but [...] > >=20 > > I think you would sound more like an unbroken clock if you would shortly > > tell the disadvantages of using `eval', then people would be more open > > to alternatives. >=20 > If possible, let me know one bad example in my context of expanding > plain text with embedded Emacs Lisp. I tried to offer an explanation which you chose to ignore [1] . I think the problem is more subtle, and thus difficult to explain in just a few words. If it were that easy to explain clearly, I think Stefan would have done that already. > Like how it can go wrong that in same time cannot go wrong in same > replacement method? >=20 > And which replacement method could I use? >=20 > Like why did Lisp authors the `read-from-string' function if it should > not be used? It is quite common that its result will be given to `eval'. It's not as clear-cut as "should not be used". Rather something along the lines of "should be used with care" [2]. Template expansion is one of those borderline cases, but if you look at all those modern template expanders out there [3], you'll realise that they all have some kind of "custom evaluator", where you explicitly provide an environment, instead of just punting to `eval' and saying "use... uh, whatever". For a reason [4]. Cheers [1] Which, to be honest, is somewhat confusing to me. [2] Yes, do it: enter the phrase "eval is evil" into your favourite search engine. [3] e.g. Perl's Text::Template, Python's Jinja2, you name it. [4] Perhaps one short way to express it would be "this havocs the compiler". Dunno. - t --wzJLGUyc3ArbnUjN Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) iEYEARECAAYFAmCOa6cACgkQBcgs9XrR2kazRACfdk2AlqfK2HgZ+UbMe6Mx+yer BVoAn3jEfUx1QnAWpM6DldPkZVLJQoeV =AS90 -----END PGP SIGNATURE----- --wzJLGUyc3ArbnUjN--