drbrain	2012-06-02 07:05:46 +0900 (Sat, 02 Jun 2012)

  New Revision: 35862

  http://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=rev&revision=35862

  Log:
    * doc/re.rdoc (Performance):  Replaced incorrect example of reducing
      backtracking through anchoring with reduced backtracking through a
      range.  [ruby-trunk - Bug #6525]

  Modified files:
    trunk/ChangeLog
    trunk/doc/re.rdoc

Index: doc/re.rdoc
===================================================================
--- doc/re.rdoc	(revision 35861)
+++ doc/re.rdoc	(revision 35862)
@@ -640,9 +640,10 @@
 while still matching the mandatory 29. It is plain to us that none of the
 optional matches can succeed, but this fact unfortunately eludes Ruby.
 
-One approach for improving performance is to anchor the match to the
-beginning of the string, thus significantly reducing the amount of
-backtracking needed.
+The best way to improve performance is to significantly reduce the amount of
+backtracking needed.  For this case, instead of individually matching 29
+optional <i>a</i>s, a range of optional <i>a</i>s can be matched all at once
+with <i>a{0,29}</i>:
 
-    Regexp.new('\A' 'a?' * 29 + 'a' * 29) =~ 'a' * 29
+    Regexp.new('a{0,29}' + 'a' * 29) =~ 'a' * 29
 
Index: ChangeLog
===================================================================
--- ChangeLog	(revision 35861)
+++ ChangeLog	(revision 35862)
@@ -1,3 +1,9 @@
+Sat Jun  2 07:04:48 2012  Eric Hodel  <drbrain@s...>
+
+	* doc/re.rdoc (Performance):  Replaced incorrect example of reducing
+	  backtracking through anchoring with reduced backtracking through a
+	  range.  [ruby-trunk - Bug #6525]
+
 Sat Jun  2 06:34:15 2012  Eric Hodel  <drbrain@s...>
 
 	* doc/re.rdoc (Performance):  Removed useless sample output from final

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