May 2004 - Posts

• Have you ever dreamed a problem? Two nights in a row now, no sleep for me I guess...

  When I get really zoned in on a problem I can't sleep, or rather I do sleep, but it seems that somehow the topic in my head becomes the makings of some really interesting dream. I've always had mild insomnia, so I'm capable of sleeping and dreaming right Read More... Posted Wednesday, May 26, 2004 8:56 AM by jrogers | 1 Comments Filed under: Regular Expressions, Numeric Parsing

• Added some extra features to my algorithms, and so I'm posting an input batch file you can use for testing your own.

  The batch file echo's expected output, along with the ouput of the program you are running. If your output is different then you might have some code refactoring to do. As soon as I get some algorithms from third parties I'll post my full algorithm. I Read More... Posted Tuesday, May 25, 2004 8:50 PM by jrogers | 0 Comments Filed under: Regular Expressions, Numeric Parsing

• Thanks to Darren, I had to examine the process of neg-pos neg-neg ranges in addition to what I was already doing.

  Negative ranges are actually quite easy to implement. There are a couple of options: Parm1 +, Parm2 + Parm1 -, Parm2 - Parm1 -, Parm2 0 Parm1 0, Parm2 - Parm1 +, Parm2 0 Parm1 0, Parm2 + 6 options isn't that bad. We also have relative equality, but we'll Read More... Posted Tuesday, May 25, 2004 2:46 AM by jrogers | 1 Comments Filed under: Regular Expressions, Numeric Parsing

• And I thought I was done. Reducing certain cases to optional captures is easy, others are more difficult...

  Optional captures come into play when the minimum range value has fewer digits than the maximum range value. Let's take a look at some ranges that exhibit the behavior so we have a base with which to work from. The first range is a familiar one, and is Read More... Posted Tuesday, May 25, 2004 12:52 AM by jrogers | 0 Comments Filed under: Regular Expressions, Numeric Parsing

• An Algorithm has been prepared, I'm linking it into an article so you don't have to look at it if you don't want. It is a spoiler.

  The final algorithm has quite a few special cases, but I've attempted to refactor the code and make it as small as possible. For readability I've chosen to use [0-9] in place of \d. You can easily change this out and use the more common \d. Note that Read More... Posted Monday, May 24, 2004 11:33 PM by jrogers | 1 Comments Filed under: Regular Expressions, Numeric Parsing

• That range algorithm was more difficult than I originally pointed out due to some strange oddities.

  What kinds of strange oddities would I be talking about? Well, check out the following oddity: 699 through 700 699|700 699 through 701 699|70[01] 699 through 718 699|70\d|71[0-8] 698 through 701 69[89]|70[01] You start to get the picture. There are some Read More... Posted Monday, May 24, 2004 8:51 PM by jrogers | 4 Comments Filed under: Numeric Parsing

• Playing with the Regulator utility and I quickly find myself being second guessed by the Intellisense...

  I can honestly say that I really don't like intellisense, but the addition of intellisense with the Regulator application is probably pretty powerful for a large number of users. I started playing with the beta, and figured I'd load up some patterns that Read More... Posted Saturday, May 22, 2004 10:24 PM by jrogers | 2 Comments Filed under: Regular Expressions

• 0 through N ranges are interesting, but what about M through N ranges.

  You can read about the decomposition of 0 through N ranges here Value range parsing using Regular Expressions. Breaking down the dotted decimal IP byte processing. Make sure to read the comments, because there is a way to use even fewer decompositions Read More... Posted Saturday, May 22, 2004 6:40 PM by jrogers | 2 Comments Filed under: Numeric Parsing

• Running your expressions asynchronously and making them cancellable.

  I blogged this over on weblogs, but I think this was the better spot for it. I'll definitely fix the classes up a bit more and add some additional functionality. For one, I'd like to add batching so you could run a bunch of them with timing metrics. Asynchronous Read More... Posted Friday, May 21, 2004 11:55 PM by jrogers | 0 Comments Filed under: Regular Expressions

• Value range parsing using Regular Expressions. Breaking down the dotted decimal IP byte processing.

  A quick look around yields the following piece of code for matching a number in the range of 0 to 255: (25[0-5]|2[0-4]\d|[01]\d\d|\d?\d) I ran into the same problem with my numeric processing utilities, however, I could use overflow to combat the problem Read More... Posted Friday, May 21, 2004 2:25 PM by jrogers | 3 Comments Filed under: Regular Expressions, Numeric Parsing