Retrieve object method - scala

Question

I have an "object" with the following typo within a string: {myObjectIdIKnow?someInfo,{someBracedInfo},{someOtherBracedInfo},someInfo,...,lastInfo}.
I want to retrieve its content (i.e. from someInfo to lastInfo).
Following, the function I built:
def retrieveMyObject(line: String, myObjectId: String) =
{
if (line.contains(myObjectId))
{
var openingDelimiterCount = 0
var closingDelimiterCount = 0
val bit = iLine.split(myObjectIdIKnow).last
var i = -1
do
{
i += 1
if (bit(i).equals("{")) openingDelimiterCount += 1
else if (bit(i).equals("}")) closingDelimiterCount += 1
} while (lDelimiterOpeningCount >= closingDelimiterCount)
if (i.equals(0)) bit
else bit.splitAt(i)._1
}
}
I match with my myObjectId and browse through each character of the input line to check if it is a brace delimiter or not, then compare the numbers of { and }: if the second is bigger than the first, it means I reached the end of my content and thus I retrieve it.
It does not seem like a good method at all and I was wondering what better way could I do it?

Answer 1

I've tried to implement simple parser using Scala Parser Combinators. Here is what I got. I'm not very experienced with parser combinator but did something working just for the sake of curiosity.
import scala.util.parsing.combinator.JavaTokenParsers
case class InfoObject(id: String, objInfo: String, bracedInfos: List[String], infos: List[String])
class ObjectParser extends JavaTokenParsers {
def objDefinition: Parser[InfoObject] = "{" ~> (idPlusInfo <~ ",") ~ (bracedInfos <~ ",") ~ infos <~ "}" ^^ {
case (id, objInfo) ~ bracedInfos ~ infos => InfoObject(id, objInfo, bracedInfos, infos)
}
def idPlusInfo: Parser[(String, String)] = (infoObj <~ "?") ~ infoObj ^^ { case id ~ info => (id, info) }
def bracedInfos: Parser[List[String]] = repsep(bracedInfo, ",")
def bracedInfo: Parser[String] = "{" ~> infoObj <~ "}"
def infos: Parser[List[String]] = repsep(infoObj, ",")
def infoObj: Parser[String] = """\w+""".r
}
val parser = new ObjectParser()
parser.parse(parser.infoObj, "someInfo").get == "someInfo" // true
parser.parse(parser.bracedInfo, "{someBracedInfo}").get == "someBracedInfo" // true
val expected = InfoObject(
"myObjectIdIKnow",
"someInfo",
List("someBracedInfo", "someOtherBracedInfo"),
List("someInfo", "lastInfo")
)
val objectDef = "{myObjectIdIKnow?someInfo,{someBracedInfo},{someOtherBracedInfo},someInfo,lastInfo}"
parser.parse(parser.objDefinition, objectDef).get == expected // true