Advanced control of recursive parser in scala

Question

val uninterestingthings = ".".r
val parser = "(?ui)(regexvalue)".r | (uninterestingthings~>parser)

This recursive parser will try to parse "(?ui)(regexvalue)".r until the end of input. Is in scala a way to prohibit parsing when some defined number of characters were consumed by "uninterestingthings" ?

UPD: I have one poor solution:

object NonRecursiveParser extends RegexParsers with PackratParsers{
  var max = -1
  val maxInput2Consume = 25
  def uninteresting:Regex ={
    if(max<maxInput2Consume){
    max+=1
    ("."+"{0,"+max.toString+"}").r
    }else{
      throw new Exception("I am tired")
    }
  }
  lazy val value = "itt".r
  def parser:Parser[Any] = (uninteresting~>value)|parser
  def parseQuery(input:String) = {
      try{
      parse(parser, input)
      }catch{
          case e:Exception => 
      }
  }
}

Disadvantages:
- not all members are lazy vals so PackratParser will have some time penalty
- constructing regexps on every "uninteresting" method call - time penalty
- using exception to control program - code style and time penalty

Answer 1

The quick-n-dirty answer is to just limit the number of characters in your regex for uninterestingthings and make it not recursive:

val uninterestingthings = ".{0,60}".r  // 60-chars max
val parser = (uninterestingthings~>"(?ui)(regexvalue)".r)*

---

Based on the comment about greediness eating the regexvalue, I propose a single regex:

val parser = ("(?.{0,60}?)(?ui)(regexvalue)".r)*

But we seem to have ventured outside the realm of scala parsers into regex minutia. I'd be interested in seeing other results.