From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: David Kastrup Newsgroups: gmane.lisp.guile.bugs Subject: bug#17485: [PATCH 3/3] Reimplement reduce-right in srfi-1 Date: Tue, 3 Jun 2014 20:56:18 +0200 Message-ID: <1401821778-19972-3-git-send-email-dak@gnu.org> References: <1401821778-19972-1-git-send-email-dak@gnu.org> NNTP-Posting-Host: plane.gmane.org X-Trace: ger.gmane.org 1401821838 29683 80.91.229.3 (3 Jun 2014 18:57:18 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 3 Jun 2014 18:57:18 +0000 (UTC) Cc: David Kastrup To: 17485@debbugs.gnu.org Original-X-From: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Tue Jun 03 20:57:11 2014 Return-path: Envelope-to: guile-bugs@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 1WrttW-0000Ol-SB for guile-bugs@m.gmane.org; Tue, 03 Jun 2014 20:57:10 +0200 Original-Received: from localhost ([::1]:55232 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WrttW-0007N0-HT for guile-bugs@m.gmane.org; Tue, 03 Jun 2014 14:57:10 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:50203) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WrttT-0007MD-3j for bug-guile@gnu.org; Tue, 03 Jun 2014 14:57:07 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WrttP-0008QY-9E for bug-guile@gnu.org; Tue, 03 Jun 2014 14:57:07 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:43651) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WrttP-0008QS-5c for bug-guile@gnu.org; Tue, 03 Jun 2014 14:57:03 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.80) (envelope-from ) id 1WrttO-0007Ck-LV for bug-guile@gnu.org; Tue, 03 Jun 2014 14:57:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: David Kastrup Original-Sender: "Debbugs-submit" Resent-CC: bug-guile@gnu.org Resent-Date: Tue, 03 Jun 2014 18:57:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 17485 X-GNU-PR-Package: guile X-GNU-PR-Keywords: Original-Received: via spool by 17485-submit@debbugs.gnu.org id=B17485.140182179527615 (code B ref 17485); Tue, 03 Jun 2014 18:57:02 +0000 Original-Received: (at 17485) by debbugs.gnu.org; 3 Jun 2014 18:56:35 +0000 Original-Received: from localhost ([127.0.0.1]:42521 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Wrtsw-0007BI-Mz for submit@debbugs.gnu.org; Tue, 03 Jun 2014 14:56:35 -0400 Original-Received: from fencepost.gnu.org ([208.118.235.10]:54712 ident=Debian-exim) by debbugs.gnu.org with esmtp (Exim 4.80) (envelope-from ) id 1Wrtsu-0007B8-OZ for 17485@debbugs.gnu.org; Tue, 03 Jun 2014 14:56:33 -0400 Original-Received: from localhost ([127.0.0.1]:33784 helo=lola) by fencepost.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Wrtst-0001m7-AG; Tue, 03 Jun 2014 14:56:31 -0400 Original-Received: by lola (Postfix, from userid 1000) id AF992DF329; Tue, 3 Jun 2014 20:56:30 +0200 (CEST) X-Mailer: git-send-email 1.9.1 In-Reply-To: <1401821778-19972-1-git-send-email-dak@gnu.org> X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.15 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 140.186.70.43 X-BeenThere: bug-guile@gnu.org List-Id: "Bug reports for GUILE, GNU's Ubiquitous Extension Language" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Original-Sender: bug-guile-bounces+guile-bugs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.lisp.guile.bugs:7481 Archived-At: * module/srfi/srfi-1.scm (reduce-right): Avoid use of drop-right in connection with last as a single upfront reverse is more efficient and simpler to understand. Signed-off-by: David Kastrup --- module/srfi/srfi-1.scm | 5 +---- 1 file changed, 1 insertion(+), 4 deletions(-) diff --git a/module/srfi/srfi-1.scm b/module/srfi/srfi-1.scm index 73d164a..6aa249a 100644 --- a/module/srfi/srfi-1.scm +++ b/module/srfi/srfi-1.scm @@ -573,10 +573,7 @@ then that's the return value." F is on two elements from LST, rather than one element and a given initial value. If LST is empty, RIDENTITY is returned. If LST has just one element then that's the return value." - (check-arg procedure? f reduce) - (if (null? lst) - ridentity - (fold-right f (last lst) (drop-right lst 1)))) + (reduce f ridentity (reverse lst))) (define map (case-lambda -- 1.9.1