For certain pattern (lookahead + loop + branch) the FirstCharSet was wrong
(?:X|(?=a))+|b
The first part up to the | could match either X or an empty string followed by a (match one or more times).
So for the entire pattern, first char could be in Xab.
But FirstCharset would only have Xb.
I added tests by creating variations of nested expressions => that leads to a big amount of tests, and therefore the runtime of the test slows done noticeable.
But on the other hand it caught the above bug. I think its worth the extra runtime.
For certain pattern (lookahead + loop + branch) the FirstCharSet was wrong
(?:X|(?=a))+|bThe first part up to the
|could match eitherXor anempty string followed by a(match one or more times). So for the entire pattern, first char could be in Xab.But FirstCharset would only have Xb.
I added tests by creating variations of nested expressions => that leads to a big amount of tests, and therefore the runtime of the test slows done noticeable.
But on the other hand it caught the above bug. I think its worth the extra runtime.