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writing readable regular expressions

 
author & internet detective
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I wrote a (simplified) US phone number validation both with and without regular expressions as a blog post. i was surprised at how much code the non regular expression version was. It's been a while since I've tried to do so "the long way"
 
Bartender
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I like that. I had to do something similar long hand in C++ last term as practice on operator >> overloading - but with the additional validation that area code and exchange could not begin with 0 or 1.
Your regex is so much prettier. Thanks for sharing it's elegance.

I must be blind, but is there a blog subscription button on your site?
 
Rancher
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Slightly off-topic since it's not germane to what you intended to show with this example: There are so many ways in which people commit typos, or think something could/should be written, that I think it's preferable to allow anything that can reasonable be interpreted as correct data. In this case that would mean to remove anything from the input string that's not a digit, and then to check I'm left with a 10 character long string.

And, of course, you could make the regexp a lot harder to comprehend by making it self-commenting. I think that would be something like "(?# 3 digits)\\d{3}" for the first one. I have never seen the comment syntax used, but it would be interesting to hear from the person who thought this would make it easier to read :-)

@Chris: Check the page source for a few RSS feeds options.
 
Chris Barrett
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Ulf Dittmer wrote:@Chris: Check the page source for a few RSS feeds options.



Thanks Ulf. I did see that. It's just... RSS feeds are so 1990s... I was looking for the "subscribe and get as an email" button.
Anyhow, I've added the RSS feed to Safari. All is good.
 
Ulf Dittmer
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Huh, I do everything I can to get rid of such emails, and use RSS wherever I can :-)
 
Bartender
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+1 for your divide-and-conquer approach to the RE here: I'll try to remember that next time I'm in Regex Hell!
 
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