Is there a concise description of how this library works? Apparently I need to read source code to find out whether or not it's a backtracker, etc.
One interesting thing I found is that it appears to support intersection and negation, as documented here: https://github.com/arnoldrobbins/mcilroy-regex/blob/master/R...
Running `make` will build its `grep` utility, and using `grep -A` enables the intersection and negation features.