I can't load the site, so I'm not sure exactly what it's offering, but I'm also not sure what you mean by a regex for zipcodes. Surely it'd be simpler, quicker, and more maintainable just to match /(\d{5})/ and filter out invalid codes after the fact?
(Edit: If you want the full ZIP+4 where it's given, you can add (\-\d{4})? as a term in the regex, and you can validate them the same way. USPS also offers an API for validating address information; it's been some years since I used it, and I recall it being somewhat recondite in the fashion of most .gov APIs, but it's there and it works.)
Edit again: OK, the site loaded. It looks like a tool for generating regexes via machine learning techniques to match highly complex targets. From a purely technical perspective, that sounds really neat -- but from a maintainability perspective, it sounds like even more of a nightmare than complex regexes usually are.
(Edit: If you want the full ZIP+4 where it's given, you can add (\-\d{4})? as a term in the regex, and you can validate them the same way. USPS also offers an API for validating address information; it's been some years since I used it, and I recall it being somewhat recondite in the fashion of most .gov APIs, but it's there and it works.)
Edit again: OK, the site loaded. It looks like a tool for generating regexes via machine learning techniques to match highly complex targets. From a purely technical perspective, that sounds really neat -- but from a maintainability perspective, it sounds like even more of a nightmare than complex regexes usually are.