I started porting Rinku and quickly realized that 99% of it is just raw C code working with character arrays.
So I started poking around for a Java autolinking library, and I found this: autolink 0.8.0 javadoc (org.nibor.autolink)
Even better, it accepts CharSequence, which means we should just be able to pass it a Ruby string (or one of our representations of it) and it will function mostly without pre-transcoding everything into Java characters.
I’ll see if I can get some basic API equivalent wrapper around it.