Implemented user defined operator candidates.

ICSharpCode.NRefactory/CSharp/Resolver/CSharpResolver.cs

@@ -443,7 +443,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 					throw new InvalidOperationException();
 			}
 			OverloadResolution r = new OverloadResolution(context, new[] { expression });
-			foreach (var candidate in methodGroup) {
+			foreach (var candidate in methodGroup.Concat(GetUserDefinedUnaryOperatorCandidates (type, GetOverloadableOperatorName(op)))) {
 				r.AddCandidate(candidate);
 			}
 			UnaryOperatorMethod m = (UnaryOperatorMethod)r.BestCandidate;
@@ -570,6 +570,21 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 				get { return baseMethod.Parameters; }
 			}
 		}
+		
+		sealed class UserDefinedUnaryOperatorMethod : UnaryOperatorMethod
+		{
+			public UserDefinedUnaryOperatorMethod (IMethod baseOperator)
+			{
+				foreach (var p in baseOperator.Parameters)
+					Parameters.Add (p);
+				ReturnType = baseOperator.ReturnType;
+			}
+			
+			public override object Invoke(CSharpResolver resolver, object input)
+			{
+				return null;
+			}
+		}
 		#endregion
 		
 		#region Unary operator definitions
@@ -612,13 +627,16 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		);
 		#endregion
 		
-		object GetUserUnaryOperatorCandidates()
+		
+		#region User defined unary operators
+		IEnumerable<OperatorMethod> GetUserDefinedUnaryOperatorCandidates (IType type, string operatorName)
 		{
 			// C# 4.0 spec: §7.3.5 Candidate user-defined operators
-			// TODO: implement user-defined operators
-			throw new NotImplementedException();
+			Predicate<IMethod> filter =  m => m.IsOperator && m.Name == operatorName;
+			return type.GetMethods (context, filter).Select (op => new UserDefinedUnaryOperatorMethod (op));
 		}
 		#endregion
+		#endregion
 		
 		#region ResolveBinaryOperator
 		#region ResolveBinaryOperator method
@@ -825,7 +843,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 					throw new InvalidOperationException();
 			}
 			OverloadResolution r = new OverloadResolution(context, new[] { lhs, rhs });
-			foreach (var candidate in methodGroup) {
+			foreach (var candidate in methodGroup.Concat (GetUserDefinedBinaryOperatorCandidates (lhsType, rhsType, GetOverloadableOperatorName (op)))) {
 				r.AddCandidate(candidate);
 			}
 			BinaryOperatorMethod m = (BinaryOperatorMethod)r.BestCandidate;
@@ -1103,6 +1121,27 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 				get { return baseMethod.Parameters; }
 			}
 		}
+		
+		sealed class UserDefinedBinaryOperatorMethod : BinaryOperatorMethod
+		{
+			public override bool CanEvaluateAtCompileTime {
+				get {
+					return false;
+				}
+			}
+			
+			public UserDefinedBinaryOperatorMethod (IMethod baseOperator)
+			{
+				foreach (var p in baseOperator.Parameters)
+					Parameters.Add (p);
+				ReturnType = baseOperator.ReturnType;
+			}
+			
+			public override object Invoke(CSharpResolver resolver, object lhs, object rhs)
+			{
+				throw new NotSupportedException("Operator can't be evaluated.");
+			}
+		}
 		#endregion
 		
 		#region Arithmetic operators
@@ -1458,11 +1497,14 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		}
 		#endregion
 		
-		object GetUserBinaryOperatorCandidates()
+		IEnumerable<OperatorMethod> GetUserDefinedBinaryOperatorCandidates (IType lhsType, IType rhsType, string operatorName)
 		{
 			// C# 4.0 spec: §7.3.5 Candidate user-defined operators
-			// TODO: implement user-defined operators
-			throw new NotImplementedException();
+			Predicate<IMethod> filter =  m => m.IsOperator && m.Name == operatorName;
+			var operators = lhsType.GetMethods (context, filter);
+			if (!lhsType.Equals (rhsType))
+				operators = operators.Concat (rhsType.GetMethods (context, filter));
+			return operators.Select (op => new UserDefinedBinaryOperatorMethod (op));
 		}
 		#endregion