public static PropertyReference GetReference(string col, string path, int line, int charPositionInLine) { var agg = col + "." + path; if (KnownReferences.ContainsKey(agg)) { return KnownReferences[agg]; } var propRef = new PropertyReference(col, path, line, charPositionInLine); KnownReferences.Add(agg, propRef); return propRef; }