From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthieu Moy Subject: [PATCH] Reduce cost of deletion in levenstein distance (4 -> 3) Date: Sun, 27 May 2012 18:02:58 +0200 Message-ID: <1338134578-29011-1-git-send-email-Matthieu.Moy@imag.fr> Cc: Matthieu Moy To: git@vger.kernel.org, gitster@pobox.com X-From: git-owner@vger.kernel.org Sun May 27 18:03:47 2012 Return-path: Envelope-to: gcvg-git-2@plane.gmane.org Received: from vger.kernel.org ([209.132.180.67]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1SYfwZ-000676-0G for gcvg-git-2@plane.gmane.org; Sun, 27 May 2012 18:03:47 +0200 Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752703Ab2E0QDI (ORCPT ); Sun, 27 May 2012 12:03:08 -0400 Received: from mx1.imag.fr ([129.88.30.5]:35941 "EHLO shiva.imag.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752305Ab2E0QDF (ORCPT ); Sun, 27 May 2012 12:03:05 -0400 Received: from mail-veri.imag.fr (mail-veri.imag.fr [129.88.43.52]) by shiva.imag.fr (8.13.8/8.13.8) with ESMTP id q4RFspOh009716 (version=TLSv1/SSLv3 cipher=AES256-SHA bits=256 verify=NO); Sun, 27 May 2012 17:54:51 +0200 Received: from bauges.imag.fr ([129.88.7.32]) by mail-veri.imag.fr with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:32) (Exim 4.72) (envelope-from ) id 1SYfvn-0001I9-VW; Sun, 27 May 2012 18:03:00 +0200 Received: from moy by bauges.imag.fr with local (Exim 4.72) (envelope-from ) id 1SYfvn-0007Yc-R1; Sun, 27 May 2012 18:02:59 +0200 X-Mailer: git-send-email 1.7.10.363.g7fcd3d.dirty X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0.1 (shiva.imag.fr [129.88.30.5]); Sun, 27 May 2012 17:54:51 +0200 (CEST) X-IMAG-MailScanner-Information: Please contact MI2S MIM for more information X-MailScanner-ID: q4RFspOh009716 X-IMAG-MailScanner: Found to be clean X-IMAG-MailScanner-SpamCheck: X-IMAG-MailScanner-From: moy@imag.fr MailScanner-NULL-Check: 1338738891.85569@67nOrxIMerw26lnNPv5P+g Sender: git-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: git@vger.kernel.org Archived-At: Before this patch, a character deletion has the same cost as 2 swaps, or 4 additions, so Git prefers suggesting a completely scrambled command name to removing a character. For example, "git tags" suggests "stage", but not "tag". By setting the deletion cost to 3, we keep it higher than swaps or additions, but prefer 1 deletion to 2 swaps. "git tags" now suggests "tag" in addition to staged. Signed-off-by: Matthieu Moy --- The RFC sent earlier [1] didn't receive negative comments, so I think this is a good change. http://thread.gmane.org/gmane.comp.version-control.git/196457 help.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/help.c b/help.c index 14eefc9..fdaa90d 100644 --- a/help.c +++ b/help.c @@ -334,7 +334,7 @@ const char *help_unknown_cmd(const char *cmd) } main_cmds.names[i]->len = - levenshtein(cmd, candidate, 0, 2, 1, 4) + 1; + levenshtein(cmd, candidate, 0, 2, 1, 3) + 1; } qsort(main_cmds.names, main_cmds.cnt, -- 1.7.10.363.g7fcd3d.dirty