sampleParser.scala

/**
 * http://stackoverflow.com/questions/19009299/scala-parser-combinators-consume-until-match
 * 
 * 
 */ 

import scala.util.parsing.combinator.RegexParsers   

object MyParser extends RegexParsers {
    val beginToken: Parser[String] = "begin"
    val dontCareToken: Parser[String] = "DONT CARE"
    val text: Parser[String] = not(dontCareToken) ~> """([^\n]+)""".r
    val dontCareText: Parser[String] = not(beginToken) ~> """([^\n]+)""".r
    val skipDontCare = dontCareToken ~ dontCareText ^^ { case c => "" }

    val document: Parser[String] = 
      beginToken ~> text.+ <~ opt(skipDontCare) ^^ { 
        _.mkString("\n") 
      }
    val documents: Parser[Iterable[String]] = document.+
}


val s = """begin

Text I care about
Text I care about

DONT CARE

Text I don't care about

begin

More text I care about
"""

MyParser.parseAll(MyParser.documents,s)