August 2004 - Posts

• Another interesting timeout pattern

  I haven't had time to fully investigate the evilness of this pattern but it certainly looked interesting: Pattern: ^(([^\\/:*?<>"|]*(?<![ ]))*~+)(\.[xsl]{3})$ Input String $d_ d}ddddddddddddFoo2.xsl.xsl Share this post: email it! | bookmark it! Read More... Posted Monday, August 23, 2004 7:37 AM by digory | 4 Comments Filed under: Samples

• Invalid patterns

  I've spent some time this week looking for interesting ways to create invalid patterns. 2 of my favourites are: [\_] and... [a-Z] Share this post: email it! | bookmark it! | digg it! | reddit! | kick it! | live it! Sponsor Read More... Posted Saturday, August 21, 2004 2:38 PM by digory | 2 Comments Filed under: NYN

• Patterns which caused timeouts to occur

  It's been 2 or 3 weeks since I added timeout protection to the RegexLib.com site. During that period I've averaged 1 or 2 timed out patterns per day. I thought that I'd post a small selection of some which have caused timeout exceptions. The following Read More... Posted Thursday, August 19, 2004 12:18 AM by digory | 4 Comments Filed under: Samples

• New testing tool for RegexLib.com

  I'm playing around with some ideas for a new testing tool for RegexLib.com : http://regexlib.com/BetaTester/TestPage.aspx This tool will allow you to test patterns using clientside (VBScript or Javascript) or, serverside (.NET) engines. When using the Read More... Posted Tuesday, August 17, 2004 12:15 AM by digory | 5 Comments Filed under: Tools and Sites, RegexLib

• Cleaning a list perf. test

  Perf. test for the patterns described in Justins comment earlier - http://regexadvice.com/blogs/dneimke/archive/2004/08/03/1432.aspx#1472 . using System ; using System.Text.RegularExpressions ; namespace RegexSnippets.Tests { public class Foo { public Read More... Posted Tuesday, August 10, 2004 1:16 PM by digory | 6 Comments Filed under: Performance Tests

• Regex bug - IndexOutOfRange - when backtracking onto an empty group

  While looking for some information about a bug I stumbled across an interesting news posting by Tim Mackey . In it he identified a bug in the parser which manifests itself in an IndexOutOfRangeException thrown from the RegexInterpreter.Stack. To reproduce Read More... Posted Monday, August 09, 2004 10:17 PM by digory | 2 Comments Filed under: Samples, Bugs and Suggested Improvements

• Conditional Matching

  Conditional matching allows you to perform a test based on if...then[...else] logic. The syntax is (?if then | else ) - with the 'else' part being optional. To demonstrate, given the following 2 words: Thursday Thurday I only want to match the 'day' part Read More... Posted Monday, August 09, 2004 9:34 PM by digory | 1 Comments Filed under: Samples

• Regexinator : Visual Studio RegEx add-in for VS.NET 2003

  I just finished chatting to James and he mentioned a new project that he is involved in: Regexinator A funny name? Sure! But this sounds cool. They are also planning to have RegexLib.com webservice integration in there too by the sound of things. Any Read More... Posted Thursday, August 05, 2004 3:04 PM by digory | 3 Comments Filed under: Tools and Sites, RegexLib

• The sugary synax we love... Lookaround

  I while back, Wayne wrote a nice article titled: LookAhead LookBehind Subtleties . In it he proved - more than he imagined when he first wrote it - that there is a subtle line about when you do and do not need to use Lookaround. Tonight I was reviewing Read More... Posted Tuesday, August 03, 2004 11:35 PM by digory | 64 Comments Filed under: NYN