Accessing Scala Parser regular expression match data

Question

I wondering if it\'s possible to get the MatchData generated from the matching regular expression in the grammar below.

object DateParser extends JavaTokenParser         


        

Answer 1

I ran into a similar issue using scala 2.8.1 and trying to parse input of the form "name:value" using the RegexParsers class:

package scalucene.query

import scala.util.matching.Regex
import scala.util.parsing.combinator._

object QueryParser extends RegexParsers {
  override def skipWhitespace = false

  private def quoted = regex(new Regex("\"[^\"]+"))
  private def colon = regex(new Regex(":"))
  private def word = regex(new Regex("\\w+"))
  private def fielded = (regex(new Regex("[^:]+")) <~ colon) ~ word
  private def term = (fielded | word | quoted)

  def parseItem(str: String) = parse(term, str)
}

It seems that you can grab the matched groups after parsing like this:

QueryParser.parseItem("nameExample:valueExample") match {
  case QueryParser.Success(result:scala.util.parsing.combinator.Parsers$$tilde, _) => {
      println("Name: " + result.productElement(0) + " value: " + result.productElement(1))
  }
}