不推荐使用-Scala Regex模式匹配

Question

Currently as of Scala 2.11 using a regex expression in a pattern matching is not encouraged, unless you're matching against a Seq[Char] or Match, is there an alternative approach. Currently I've implemented a getValueV2 with the Seq[Char] strategy in the following example, though it's verbose and it doesn't look good enough.

What other suggestions do you have for replacing a regex,

trait MyHelper {
  //param Regex is deprecated
 def getValue(option: Option[scala.Any]): String = {
  val param = """(?:String|Boolean)Option\((.*)\)""".r
  option.getOrElse("") match {
    case param(s) => s
    case arr: Array[_] => arr.mkString("")
    case _ => ""
  }
}

def getValueV2(option: Option[scala.Any]): String = {
  option.getOrElse("") match {
      case s : String => s.toSeq match {
        case p if p.endsWith(")") => p match {
        case Seq('S', 't', 'r', 'i', 'n', 'g', 'O', 'p', 't', 'i', 'o', 'n', '(', suffix@_*) => suffix.toString.substring(0, suffix.length -1)
          case Seq('B', 'o', 'o', 'l', 'e', 'a', 'n', 'O', 'p', 't', 'i', 'o', 'n', '(',  suffix@_*) => suffix.toString.substring(0, suffix.length -1)
          case _ => s                   
        }
        case _ => s 
      }
      case arr: Array[_] => arr.mkString("")
      case _ => ""
    }
  }
}

I've been looking for another library called kantan.regex but It doesn't seem to have a big community. What would be the best approach here, just keep with the regex and ignore the deprecated warnings?

Answer 1

Since you're only interested in matching against String inputs, test for type before applying the Regex.

def getValue(option: Option[scala.Any]): String = {
  val param = """(?:String|Boolean)Option\((.*)\)""".r
  option.getOrElse("") match {
    case str: String => str match {
      case param(s) => s
      case _ => ""
    }
    case arr: Array[_] => arr.mkString("")
    case _ => ""
  }
}

This compiles without warning.