As someone who has crafted thousands of complex regular expression rules for data capture, here is my take:<p>1. This is a fine idea to aid regex newbies in crafting their expressions. I see this as a gateway instead of a longterm tool. The expressions won't be optimal (by no fault of the tool), nor will they likely be complete, but that's not the point. If it helps reduce the barrier(s) to adoption of regular expressions, then I can heartily support it.<p>2. To the people who say they use regular expressions only a handful of times a year, thus it's not worthwhile to invest time in learning the syntax, I offer this: once you know it, you will use it far more often than you ever expected. Find & replace text, piping output, Nginx.conf editing, or even the REGEXP() function in MySQL. It's a valuable skillset in so many environments that I expect you will use weekly, if not daily.<p>3. Ultimately regular expressions, like everything, are extra difficult until you know all of the available tools in the toolbox. At that point, you may realize you wrote an unnecessarily complex expression simply because you didn't know better.