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| author | Mark H Weaver <mhw@netris.org> | 2014-06-04 19:30:16 -0400 |
|---|---|---|
| committer | Mark H Weaver <mhw@netris.org> | 2014-06-04 19:37:50 -0400 |
| commit | 1ea8954814d124b995f2296bc6aec92adb566bc1 (patch) | |
| tree | f57c1304160b7dbbb98034c044f3935571661160 | |
| parent | 2da97f1c7c0748509180308d9e6a817bc49172e7 (diff) | |
| download | guile-1ea8954814d124b995f2296bc6aec92adb566bc1.tar.gz | |
Avoid quadratic expansion time in 'and' and 'or' macros.
Fixes <http://bugs.gnu.org/17147>.
Reported by David Kastrup <dak@gnu.org>.
* module/ice-9/boot-9.scm (and, or): Use dotted tail instead of ellipsis
in patterns.
| -rw-r--r-- | module/ice-9/boot-9.scm | 10 |
1 files changed, 5 insertions, 5 deletions
diff --git a/module/ice-9/boot-9.scm b/module/ice-9/boot-9.scm index 42d7d7837..c6d4be111 100644 --- a/module/ice-9/boot-9.scm +++ b/module/ice-9/boot-9.scm @@ -1,8 +1,6 @@ ;;; -*- mode: scheme; coding: utf-8; -*- -;;;; Copyright (C) 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003, -;;;; 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013, 2014 -;;;; Free Software Foundation, Inc. +;;;; Copyright (C) 1995-2014 Free Software Foundation, Inc. ;;;; ;;;; This library is free software; you can redistribute it and/or ;;;; modify it under the terms of the GNU Lesser General Public @@ -409,13 +407,15 @@ If there is no handler at all, Guile prints an error and then exits." (syntax-rules () ((_) #t) ((_ x) x) - ((_ x y ...) (if x (and y ...) #f)))) + ;; Avoid ellipsis, which would lead to quadratic expansion time. + ((_ x . y) (if x (and . y) #f)))) (define-syntax or (syntax-rules () ((_) #f) ((_ x) x) - ((_ x y ...) (let ((t x)) (if t t (or y ...)))))) + ;; Avoid ellipsis, which would lead to quadratic expansion time. + ((_ x . y) (let ((t x)) (if t t (or . y)))))) (include-from-path "ice-9/quasisyntax") |