title: What makes scala.util.matching.regex library different from java.util.regex library?
body: <p>As a Java developer learning Scala, I was surprised to find a <a href="http://www.scala-lang.org/api/2.11.5/index.html#scala.util.matching.Regex" rel="nofollow">separate Scala library for regular expressions</a>. The major difference seems to me to be that a lot of the Scala operations return an Option[String].  Is that the key difference or is there more I'm missing there in how those libraries are used?</p>