Not only informative, but also beautiful.
This system acts as a regular expression generator. Instead of trying to build the regular expression, you start off with the string that you want to search. You paste this into the site, click submit and the site finds recognisable patterns in your string. You then select the patterns that you are interested in and it writes a fully fledged program that extracts those patterns from that string.
A time-saver if ever I saw one.
Redkovka, Ukraine, bears little resemblance to the place it was 25 years ago. Its stores, its school, its factory, and its homes — all are gone, or dramatically changed, as a result of the 1986 nuclear accident at Chernobyl, about 22 miles away.