These expansions are certainly possible and I'm planning to investigate whether they have performance benefits. One interesting discovery we made last weeks is

These expansions are certainly possible and I'm planning to investigate whether they have performance benefits. One interesting discovery we made last weeks is that `(a|b|c)` actually produces a larger state table than `[abc]`. This was both the case for Java and Vim. While the performance gains are minute, nevertheless, they are gains. I haven't checked if "a{4}", for example, is faster than "aaaa" or produces fewer states. But it's something I am interested in. I just haven't had enough time this week.