I answered that Groovy uses Java’s regular expression support and adds a few nifty features of its own to make regular expressions easier to apply.

Complete your introduction to the Regex API, then find out how regular expressions make quicker work of common tasks like code documentation and lexical analysis.

One can achieve the same result using one or two lines of regular expression replacement, but the retort was that regular expressions, or regex, are notoriously slow. That's generally true.