[Completion] GetCurrentParameterIndex can now identify the names of

the named parameters that are used as well.

ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngineBase.cs

@@ -146,8 +146,15 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			return false;
 		}
 		
-		public int GetCurrentParameterIndex (int triggerOffset, int endOffset)
+		public int GetCurrentParameterIndex(int triggerOffset, int endOffset)
 		{
+			List<string> list;
+			return  GetCurrentParameterIndex (triggerOffset, endOffset, out list);
+		}
+
+		public int GetCurrentParameterIndex (int triggerOffset, int endOffset, out List<string> usedNamedParameters)
+		{
+			usedNamedParameters =new List<string> ();
 			char lastChar = document.GetCharAt (endOffset - 1);
 			if (lastChar == '(' || lastChar == '<') { 
 				return 0;
@@ -155,9 +162,20 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			var parameter = new Stack<int> ();
 			var bracketStack = new Stack<Stack<int>> ();
 			bool inSingleComment = false, inString = false, inVerbatimString = false, inChar = false, inMultiLineComment = false;
+			var word = new StringBuilder ();
 			for (int i = triggerOffset; i < endOffset; i++) {
 				char ch = document.GetCharAt (i);
 				char nextCh = i + 1 < document.TextLength ? document.GetCharAt (i + 1) : '\0';
+				if (ch == ':') {
+					usedNamedParameters.Add (word.ToString ());
+					word.Length = 0;
+				} else if (char.IsLetterOrDigit (ch) || ch =='_') {
+					word.Append (ch);
+				} else if (char.IsWhiteSpace (ch)) {
+
+				} else {
+					word.Length = 0;
+				}
 				switch (ch) {
 					case '{':
 						if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {