Scala parsing, how to go through what has been collected -

using scala parser combinators have parsed text input , created of own types along way. result prints fine. need go through output, presume nested structure includes types created. how go this?
how call parser:

gmparser1.parseitem(i_inputhard_2) match {   case gmparser1.success(res, _) =>     println(">" + res + "< of type: " + res.getclass.getsimplename)   case x =>      println("could not parse input string:" + x) }  

edit msgresponse(o2 flow|off) is:

>(msgresponse~(o2 flow~off))< of type: $tilde 

and wthrresponse(id(tube 25,carbon monoxide)|0.20) is:

>(wthrresponse~idwithvalue(id(tube 25,carbon monoxide),0.20))< of type: $tilde 

just give context question here of input parsing. want get at id:

trait keeper case class id(leftcontents:string,rightcontents:string) extends keeper 

and here id being created:

def id = "id(" ~> idcontents <~ ")"  ^^ { contents => id(contents._1,contents._2) }  

and here whole of parser:

object gmparser1 extends regexparsers {   override def skipwhitespace = false   def number = regex(new regex("[-+]?(\\d*[.])?\\d+"))   def idcontents = text ~ ("," ~> text)   def id = "id(" ~> idcontents <~ ")"  ^^ { contents => id(contents._1,contents._2) }   def text = """[a-za-z0-9* ]+""".r   def wholeword = """[a-za-z]+""".r   def idbracketcontents = id ~ ( "|" ~> number ) ^^ { contents => idwithvalue(contents._1,contents._2) }   def nonidbracketcontents = text ~ ( "|" ~> text )   def bracketcontents = idbracketcontents | nonidbracketcontents   def outerbrackets = "(" ~> bracketcontents <~ ")"   def target = wholeword ~ outerbrackets   def parseitem(str: string): parseresult[any] = parse(target, str)    trait keeper   case class id(leftcontents:string,rightcontents:string) extends keeper   case class idwithvalue(leftcontents:id,numbercontents:string) extends keeper } 

the parser created ~ operator produces value of ~ case class. @ contents, can pattern match on over other case class (keeping in mind name symbolic, it's used infix).

so can replace case gmparser1.success(res, _) => ... case gmparser1.success(functionname ~ argument) => ... @ function name , argument (or whatever semantics of wholeword , bracketcontents in wholeword "(" bracketcontents ")" are). can use nested pattern @ individual parts of argument.

you (and should) use ^^ pattern matching in rules create more meaningful ast structure doesn't contain ~. useful distinguish nonidbracketcontents result bracketcontents result example.