I typed "an email address" and it came up with

    [a-zA-Z0-9._%+-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,}

which is similar, but has some interesting differences. That shows it's black-box association. Then I tried "my email address" and this came out, line break included

   is john.doe@example.com
   My email address is \w+\.\w+@\w+\.\w+

"An identifier" vs "a Javascript identifier" does work as expected, but "a number" and "a floating point number" don't. "A quoted string" doesn't escape the quotes inside, but if you add "with escaped quotes" it does.

So, it's cute, and might set you on the right track, as long as you study the output a bit.