From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.help Subject: Re: Lookarounds and recursion in Emacs regexes Date: Sun, 05 Feb 2023 07:51:43 +0200 Message-ID: <831qn4u0b4.fsf@gnu.org> References: <87h6wbeti3.fsf@mbork.pl> <877cx7n5an.fsf@dataswamp.org> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="19561"; mail-complaints-to="usenet@ciao.gmane.io" To: help-gnu-emacs@gnu.org Original-X-From: help-gnu-emacs-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Sun Feb 05 06:52:07 2023 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 1pOXwc-0004tF-Mk for geh-help-gnu-emacs@m.gmane-mx.org; Sun, 05 Feb 2023 06:52:06 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pOXwA-0001Gu-9E; Sun, 05 Feb 2023 00:51:38 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pOXw8-0001Gk-Kh for help-gnu-emacs@gnu.org; Sun, 05 Feb 2023 00:51:36 -0500 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pOXw8-0007xg-CG for help-gnu-emacs@gnu.org; Sun, 05 Feb 2023 00:51:36 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=Yp79l0lSe8M62pXxX+nmF+i90rOIxOmSCH0izFf4il4=; b=q6PdUNZX5SCc QYXvsWvdGxP4CnxxJmEKdlESZLTJ8JbmAjePXAhTT/LCGYqbbAAXN3WrIrw5XspizwLODiSWITcLV /QGL6Y9HRRJDsYMxCdX2AU+HLejWs/audGyueqdxmfrAYF3Gx3qlfBIP0X6KzckEfvdUIwcsTUmQo yvVXmBtS+WZjOx7XPFkUZGz7jC2VppuMd76P7iku0M4AwQPbY3/WKX9cw6Ih8xanu6PIAljrtJbPG X4LO77Dz+ytMFxyXibaoWC5sTK/LDKL9Ku8Rl5kFE8fT5ibUnUz2FMTbsmbBK5naMAM4fyoMLBTox oAfXAy/DIu6I9J2hj6gbFw==; Original-Received: from [87.69.77.57] (helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pOXw7-00019P-Mq for help-gnu-emacs@gnu.org; Sun, 05 Feb 2023 00:51:36 -0500 In-Reply-To: (message from Stefan Monnier via Users list for the GNU Emacs text editor on Sat, 04 Feb 2023 17:28:11 -0500) X-BeenThere: help-gnu-emacs@gnu.org X-Mailman-Version: 2.1.29 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-bounces+geh-help-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.help:142606 Archived-At: > Date: Sat, 04 Feb 2023 17:28:11 -0500 > From: Stefan Monnier via Users list for the GNU Emacs text editor > > There's a common confusion that ELisp is some kind of extension language > for Emacs. That's not quite true. ELisp is an *implementation* > language of Emacs (along with C for the other half). That depends on what one considers as "Emacs" and what as "extensions". And besides, given that Emacs extends itself, what exactly are the significant and fundamental differences between "extension language" and "implementation language"? > It doesn't prevent adding other extension languages, nor even does it > necessarily prevent changing the implementation language to another one > in theory. Indeed, but replacing ELisp would probably need to rewrite a lot of internals currently implemented in C, since most, if not all, of them are currently very tightly coupled with Lisp and assume the existence and design/implementation of various aspects of the Lisp machine.