From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.help Subject: Re: compiler macros without byte-compilation Date: Fri, 20 Mar 2015 09:42:06 -0400 Message-ID: References: <871tkkf1g9.fsf@yahoo.fr> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1426858997 28177 80.91.229.3 (20 Mar 2015 13:43:17 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 20 Mar 2015 13:43:17 +0000 (UTC) To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Fri Mar 20 14:43:09 2015 Return-path: Envelope-to: geh-help-gnu-emacs@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 1YYxCW-0005MZ-Qf for geh-help-gnu-emacs@m.gmane.org; Fri, 20 Mar 2015 14:43:00 +0100 Original-Received: from localhost ([::1]:43872 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYxCW-0001dM-9w for geh-help-gnu-emacs@m.gmane.org; Fri, 20 Mar 2015 09:43:00 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:55232) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYxCL-0001dH-Td for help-gnu-emacs@gnu.org; Fri, 20 Mar 2015 09:42:50 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YYxCH-0003ly-JD for help-gnu-emacs@gnu.org; Fri, 20 Mar 2015 09:42:49 -0400 Original-Received: from plane.gmane.org ([80.91.229.3]:49888) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYxCH-0003lg-Cp for help-gnu-emacs@gnu.org; Fri, 20 Mar 2015 09:42:45 -0400 Original-Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1YYxBz-0004t8-US for help-gnu-emacs@gnu.org; Fri, 20 Mar 2015 14:42:28 +0100 Original-Received: from 69-165-152-31.dsl.teksavvy.com ([69.165.152.31]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 20 Mar 2015 14:42:27 +0100 Original-Received: from monnier by 69-165-152-31.dsl.teksavvy.com with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Fri, 20 Mar 2015 14:42:27 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 20 Original-X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 69-165-152-31.dsl.teksavvy.com User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) Cancel-Lock: sha1:/qrcJNJPj98vIrLkYiaGZd2Htwo= X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 80.91.229.3 X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.14 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.org@gnu.org Original-Sender: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.help:103223 Archived-At: > => ((lambda nil (message "Done !")) "compiler-macro") > Now I'm puzzled : why does this happen ? foobar wasn't compiled here ! The exact cases where compiler-macros are used are unspecified and likely to change between versions. If you want to know the details: compiler-macros are expanded by macroexpand-all. So everytime we rely on macroexpand-all (i.e. "eager" expansion) rather than on macroexpand (i.e. "lazy" expansion), compiler macros will be expanded. "Lazy" macroexpansion is on the way out: `eval' does not call macroexpand-all (because it can happen that `eval' is called repeatedly in a tight loop to evaluate very short code sequences, where going through macroexpand-all might be detrimental for performance), but pretty much all other paths to `eval' do or should (i.e. `load', `eval-region', ...). Stefan