pattern: allow * to match non-leading dots

[paulhammond]

I was checking your recent changes to how pattern/expand support * and ., and I think there's a mistake in commit ce872e7. The rules that prevent * from matching dots in filenames only apply to the first character. In other words "foo*" should match "foo.suffix". This PR fixes that bug.

[mvdan]

Dang, well spotted.

[mvdan]

I think the same fix needs to happen for foo**, as it effectively behaves like foo*. We might need to refactor the code a bit to allow reusing some of these regex pieces.

[paulhammond]

Good point. I just added a followup commit with the naive implementation for ** but you're right that these conditionals are getting pretty complicated. I'll try to take some time to clean it up in the next few days, but if you want to do the work yourself before I get to it I won't mind.

[mvdan]

No need, I'll be sending some changes to improve the tests and refactor the code a bit.

[mvdan]

I'm done with those changes as of 93f7ac2. There is no duplication for handling wildcards now, and the highest amount of indentation in that code is down from 7 tabs to 5. The lexer added a bit of verbosity to the code, but I thought it would make the translator a bit more principled and maintainable in the long run.

[paulhammond]

Looks good! Thanks again for all the hard work here