LOL, who remembers their class on functional programming? Use a fucking accumulator and continuation to make your regexp matcher tail-recursive so it doesn’t cause stack-overflows!

Or just, you know, make and optimize a finite automaton like a normal person instead of making a (recursive) matcher, you dolts!

java.lang.StackOverflowError
at org.apache.xerces.impl.xpath.regex.RegularExpression.matchString(Unknown Source)
at org.apache.xerces.impl.xpath.regex.RegularExpression.matchString(Unknown Source)