Support for capture groups

[vincent-lg]

As you know, capture groups aren't only useful for replacing, they're pretty useful for extracting too. I have trouble finding this feature in this Python port, although the JS documentation includes methods for beginCapture and endCapture. Am I missing something obvious?

[DonaldTsang]

Might wanna ask in https://github.com/VerbalExpressions/JSVerbalExpressions