From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Juri Linkov Newsgroups: gmane.emacs.devel Subject: Re: occur API change proposal Date: Sat, 01 Dec 2007 02:34:35 +0200 Organization: JURTA Message-ID: <87fxyni898.fsf@jurta.org> References: <861wa92g6a.fsf@lifelogs.com> NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: ger.gmane.org 1196470049 8725 80.91.229.12 (1 Dec 2007 00:47:29 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sat, 1 Dec 2007 00:47:29 +0000 (UTC) Cc: emacs-devel@gnu.org To: Ted Zlatanov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Dec 01 01:47:37 2007 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([199.232.76.165]) by lo.gmane.org with esmtp (Exim 4.50) id 1IyGW3-00052X-Kc for ged-emacs-devel@m.gmane.org; Sat, 01 Dec 2007 01:47:36 +0100 Original-Received: from localhost ([127.0.0.1] helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IyGVk-0002me-PP for ged-emacs-devel@m.gmane.org; Fri, 30 Nov 2007 19:47:12 -0500 Original-Received: from mailman by lists.gnu.org with tmda-scanned (Exim 4.43) id 1IyGVH-0002bL-83 for emacs-devel@gnu.org; Fri, 30 Nov 2007 19:46:43 -0500 Original-Received: from exim by lists.gnu.org with spam-scanned (Exim 4.43) id 1IyGVC-0002Zq-R1 for emacs-devel@gnu.org; Fri, 30 Nov 2007 19:46:42 -0500 Original-Received: from [199.232.76.173] (helo=monty-python.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1IyGVC-0002Zn-Kf for emacs-devel@gnu.org; Fri, 30 Nov 2007 19:46:38 -0500 Original-Received: from relay03.kiev.sovam.com ([62.64.120.201]) by monty-python.gnu.org with esmtps (TLS-1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.60) (envelope-from ) id 1IyGVB-0006eV-6F for emacs-devel@gnu.org; Fri, 30 Nov 2007 19:46:38 -0500 Original-Received: from [83.170.232.243] (helo=smtp.svitonline.com) by relay03.kiev.sovam.com with esmtp (Exim 4.67) (envelope-from ) id 1IyGUe-000PtG-RE; Sat, 01 Dec 2007 02:46:05 +0200 In-Reply-To: <861wa92g6a.fsf@lifelogs.com> (Ted Zlatanov's message of "Thu, 29 Nov 2007 10:02:37 -0600") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.0.50 (gnu/linux) X-Scanner-Signature: 233cb89e4cdd9c68f6fe52a505261b56 X-DrWeb-checked: yes X-SpamTest-Envelope-From: juri@jurta.org X-SpamTest-Group-ID: 00000000 X-SpamTest-Header: Not Detected X-SpamTest-Info: Profiles 1836 [Nov 30 2007] X-SpamTest-Info: helo_type=3 X-SpamTest-Info: {HEADERS: header Content-Type found without required header Content-Transfer-Encoding} X-SpamTest-Method: none X-SpamTest-Rate: 19 X-SpamTest-Status: Not detected X-SpamTest-Status-Extended: not_detected X-SpamTest-Version: SMTP-Filter Version 3.0.0 [0255], KAS30/Release X-detected-kernel: by monty-python.gnu.org: FreeBSD 4.7-5.2 (or MacOS X 10.2-10.4) (2) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:84397 Archived-At: > I propose changing the occur API to allow an optional predicate > function. For example, this is useful to invert a regular expression so > you don't have to run occur on the whole buffer matching everything, > then limit the results. The occur engine currently hard-codes the function call of `re-search-forward'. Instead of this, we could do the same as is done already in isearch for customization of the search function using a variable `isearch-search-fun-function', and add a new analogous variable `occur-fun-function'. Even though such a variable will be useful for other purposes, no simple function will allow inverting a regular expression. Implementing this feature requires significant modification in the logic of the occur engine: either changing the algorithm to call `looking-at' at every line (very inefficient), or recording a position of the previous match and outputing lines between it and the current position (not easy to customize). -- Juri Linkov http://www.jurta.org/emacs/