Yes, the linked example falls in the category of "particularly simple patterns" I mentioned. This strategy only works for such simple patterns; add in a single

Yes, the linked example falls in the category of "particularly simple patterns" I mentioned. This strategy only works for such simple patterns; add in a single alternation with a common base and the naïve iteration strategy falls apart. Implementing a sensible algorithm to evaluate such a pattern would require much more code than a couple of brackets, would not benefit from RegEx caching, etc.