Fixed issues with LogicalAnd and LogicalOr operators.

Add unit tests for overload resolution; fixed an overload resolution bug.
Added some new helper methods.
Various documentation updates.

.gitignore

@@ -0,0 +1,2 @@
+/lib/*.dll
+/ICSharpCode.NRefactory.Tests/PartCover/*

ICSharpCode.NRefactory.Tests/CSharp/Resolver/BinaryOperatorTests.cs

@@ -257,6 +257,9 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			
 			AssertConstant(false, resolver.ResolveBinaryOperator(
 				BinaryOperatorType.GreaterThan, MakeConstant(StringComparison.CurrentCultureIgnoreCase), MakeConstant(StringComparison.Ordinal)));
+			
+			AssertType(typeof(bool), resolver.ResolveBinaryOperator(
+				BinaryOperatorType.GreaterThan, MakeResult(typeof(StringComparison?)), MakeResult(typeof(StringComparison?))));
 		}
 		
 		[Test]
@@ -310,6 +313,32 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 				BinaryOperatorType.BitwiseOr, MakeConstant(0), MakeConstant(AttributeTargets.Field)));
 		}
 		
+		[Test]
+		public void LogicalAnd()
+		{
+			AssertConstant(true, resolver.ResolveBinaryOperator(
+				BinaryOperatorType.LogicalAnd, MakeConstant(true), MakeConstant(true)));
+			
+			AssertConstant(false, resolver.ResolveBinaryOperator(
+				BinaryOperatorType.LogicalAnd, MakeConstant(false), MakeConstant(true)));
+			
+			AssertError(typeof(bool), resolver.ResolveBinaryOperator(
+				BinaryOperatorType.LogicalAnd, MakeConstant(false), MakeResult(typeof(bool?))));
+		}
+		
+		[Test]
+		public void LogicalOr()
+		{
+			AssertConstant(true, resolver.ResolveBinaryOperator(
+				BinaryOperatorType.LogicalOr, MakeConstant(false), MakeConstant(true)));
+			
+			AssertConstant(false, resolver.ResolveBinaryOperator(
+				BinaryOperatorType.LogicalOr, MakeConstant(false), MakeConstant(false)));
+			
+			AssertError(typeof(bool), resolver.ResolveBinaryOperator(
+				BinaryOperatorType.LogicalOr, MakeConstant(false), MakeResult(typeof(bool?))));
+		}
+		
 		[Test]
 		public void NullCoalescing()
 		{

ICSharpCode.NRefactory.Tests/CSharp/Resolver/OverloadResolutionTests.cs

@@ -0,0 +1,106 @@
+// Copyright (c) 2010 AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under MIT X11 license (for details please see \doc\license.txt)
+
+using System;
+using System.Linq;
+using ICSharpCode.NRefactory.TypeSystem;
+using ICSharpCode.NRefactory.TypeSystem.Implementation;
+using NUnit.Framework;
+
+namespace ICSharpCode.NRefactory.CSharp.Resolver
+{
+	[TestFixture]
+	public class OverloadResolutionTests
+	{
+		readonly ITypeResolveContext context = CecilLoaderTests.Mscorlib;
+		readonly DefaultTypeDefinition dummyClass = new DefaultTypeDefinition(CecilLoaderTests.Mscorlib, string.Empty, "DummyClass");
+		
+		ResolveResult[] MakeArgumentList(params Type[] argumentTypes)
+		{
+			return argumentTypes.Select(t => new ResolveResult(t.ToTypeReference().Resolve(context))).ToArray();
+		}
+		
+		DefaultMethod MakeMethod(params Type[] parameterTypes)
+		{
+			DefaultMethod m = new DefaultMethod(dummyClass, "Method");
+			foreach (var type in parameterTypes) {
+				m.Parameters.Add(new DefaultParameter(type.ToTypeReference(), string.Empty));
+			}
+			return m;
+		}
+		
+		DefaultMethod MakeParamsMethod(params Type[] parameterTypes)
+		{
+			DefaultMethod m = MakeMethod(parameterTypes);
+			((DefaultParameter)m.Parameters.Last()).IsParams = true;
+			return m;
+		}
+		
+		[Test]
+		public void PreferIntOverUInt()
+		{
+			OverloadResolution r = new OverloadResolution(context, MakeArgumentList(typeof(ushort)));
+			var c1 = MakeMethod(typeof(int));
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(c1));
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(MakeMethod(typeof(uint))));
+			Assert.IsFalse(r.IsAmbiguous);
+			Assert.AreSame(c1, r.BestCandidate);
+		}
+		
+		[Test]
+		public void NullableIntAndNullableUIntIsAmbiguous()
+		{
+			OverloadResolution r = new OverloadResolution(context, MakeArgumentList(typeof(ushort?)));
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(MakeMethod(typeof(int?))));
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(MakeMethod(typeof(uint?))));
+			Assert.AreEqual(OverloadResolutionErrors.AmbiguousMatch, r.BestCandidateErrors);
+			
+			// then adding a matching overload solves the ambiguity:
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(MakeMethod(typeof(ushort?))));
+			Assert.AreEqual(OverloadResolutionErrors.None, r.BestCandidateErrors);
+			Assert.IsNull(r.BestCandidateAmbiguousWith);
+		}
+		
+		[Test]
+		public void ParamsMethodMatchesEmptyArgumentList()
+		{
+			OverloadResolution r = new OverloadResolution(context, MakeArgumentList());
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(MakeParamsMethod(typeof(int[]))));
+			Assert.IsTrue(r.BestCandidateIsExpandedForm);
+		}
+		
+		[Test]
+		public void ParamsMethodMatchesOneArgumentInExpandedForm()
+		{
+			OverloadResolution r = new OverloadResolution(context, MakeArgumentList(typeof(int)));
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(MakeParamsMethod(typeof(int[]))));
+			Assert.IsTrue(r.BestCandidateIsExpandedForm);
+		}
+		
+		[Test]
+		public void ParamsMethodMatchesInUnexpandedForm()
+		{
+			OverloadResolution r = new OverloadResolution(context, MakeArgumentList(typeof(int[])));
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(MakeParamsMethod(typeof(int[]))));
+			Assert.IsFalse(r.BestCandidateIsExpandedForm);
+		}
+		
+		[Test]
+		public void LessArgumentsPassedToParamsIsBetter()
+		{
+			OverloadResolution r = new OverloadResolution(context, MakeArgumentList(typeof(int), typeof(int), typeof(int)));
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(MakeParamsMethod(typeof(int[]))));
+			Assert.AreEqual(OverloadResolutionErrors.None, r.AddCandidate(MakeParamsMethod(typeof(int), typeof(int[]))));
+			Assert.IsFalse(r.IsAmbiguous);
+			Assert.AreEqual(2, r.BestCandidate.Parameters.Count);
+		}
+		
+		[Test]
+		public void CallInvalidParamsDeclaration()
+		{
+			OverloadResolution r = new OverloadResolution(context, MakeArgumentList(typeof(int[,])));
+			Assert.AreEqual(OverloadResolutionErrors.ArgumentTypeMismatch, r.AddCandidate(MakeParamsMethod(typeof(int))));
+			Assert.IsFalse(r.BestCandidateIsExpandedForm);
+		}
+	}
+}

ICSharpCode.NRefactory.Tests/CSharp/Resolver/ResolverTestBase.cs

@@ -13,6 +13,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 	public abstract class ResolverTestBase
 	{
 		protected readonly IProjectContent mscorlib = CecilLoaderTests.Mscorlib;
+		protected readonly ITypeResolveContext context = CecilLoaderTests.Mscorlib;
 		protected CSharpResolver resolver;
 		
 		[SetUp]
@@ -23,7 +24,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		
 		protected IType ResolveType(Type type)
 		{
-			IType t = type.ToTypeReference().Resolve(mscorlib);
+			IType t = type.ToTypeReference().Resolve(context);
 			if (t == SharedTypes.UnknownType)
 				throw new InvalidOperationException("Could not resolve type");
 			return t;
@@ -63,14 +64,14 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		{
 			Assert.IsFalse(rr.IsError, rr.ToString() + " is an error");
 			Assert.IsFalse(rr.IsCompileTimeConstant, rr.ToString() + " is a compile-time constant");
-			Assert.AreEqual(expectedType.ToTypeReference().Resolve(mscorlib), rr.Type);
+			Assert.AreEqual(expectedType.ToTypeReference().Resolve(context), rr.Type);
 		}
 		
 		protected void AssertError(Type expectedType, ResolveResult rr)
 		{
 			Assert.IsTrue(rr.IsError, rr.ToString() + " is not an error, but an error was expected");
 			Assert.IsFalse(rr.IsCompileTimeConstant, rr.ToString() + " is a compile-time constant");
-			Assert.AreEqual(expectedType.ToTypeReference().Resolve(mscorlib), rr.Type);
+			Assert.AreEqual(expectedType.ToTypeReference().Resolve(context), rr.Type);
 		}
 	}
 }

ICSharpCode.NRefactory.Tests/ICSharpCode.NRefactory.Tests.csproj

@@ -47,6 +47,7 @@
     <Compile Include="CSharp\Resolver\BinaryOperatorTests.cs" />
     <Compile Include="CSharp\Resolver\CastTests.cs" />
     <Compile Include="CSharp\Resolver\ConversionsTest.cs" />
+    <Compile Include="CSharp\Resolver\OverloadResolutionTests.cs" />
     <Compile Include="CSharp\Resolver\ResolverTestBase.cs" />
     <Compile Include="CSharp\Resolver\UnaryOperatorTests.cs" />
     <Compile Include="FormattingTests\TestBraceStlye.cs" />
@@ -62,6 +63,7 @@
     <Compile Include="TypeSystem\TypeSystemTests.cs" />
     <Compile Include="TypeSystem\TypeSystemTests.TestCase.cs" />
     <Compile Include="Untested.cs" />
+    <Compile Include="Util\CSharpPrimitiveCastTests.cs" />
     <Compile Include="Util\TreeTraversalTests.cs" />
   </ItemGroup>
   <ItemGroup>

ICSharpCode.NRefactory.Tests/TypeSystem/ReflectionHelperTests.cs

@@ -148,7 +148,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		}
 		
 		[Test]
-		public void ParseReflectionNameSimpleTypes()
+		public void ParseReflectionName()
 		{
 			Assert.AreEqual("System.Int32", ReflectionHelper.ParseReflectionName("System.Int32").Resolve(context).ReflectionName);
 			Assert.AreEqual("System.Int32&", ReflectionHelper.ParseReflectionName("System.Int32&").Resolve(context).ReflectionName);
@@ -157,6 +157,123 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			Assert.AreEqual("System.Action`1[[System.String]]", ReflectionHelper.ParseReflectionName("System.Action`1[[System.String]]").Resolve(context).ReflectionName);
 			Assert.AreEqual("System.Action`1[[System.String]]", ReflectionHelper.ParseReflectionName("System.Action`1[[System.String, mscorlib]]").Resolve(context).ReflectionName);
 			Assert.AreEqual("System.Int32[,,][,]", ReflectionHelper.ParseReflectionName(typeof(int[,][,,]).AssemblyQualifiedName).Resolve(context).ReflectionName);
+			Assert.AreEqual("System.Environment+SpecialFolder", ReflectionHelper.ParseReflectionName("System.Environment+SpecialFolder").Resolve(context).ReflectionName);
+		}
+		
+		[Test]
+		public void ParseOpenGenericReflectionName()
+		{
+			IMethod convertAll = context.GetClass(typeof(List<>)).Methods.Single(m => m.Name == "ConvertAll");
+			Assert.AreEqual("System.Converter`2[[?],[?]]", ReflectionHelper.ParseReflectionName("System.Converter`2[[`0],[``0]]").Resolve(context).ReflectionName);
+			Assert.AreEqual("System.Converter`2[[`0],[``0]]", ReflectionHelper.ParseReflectionName("System.Converter`2[[`0],[``0]]", convertAll).Resolve(context).ReflectionName);
+		}
+		
+		[Test, ExpectedException(typeof(ArgumentNullException))]
+		public void ParseNullReflectionName()
+		{
+			ReflectionHelper.ParseReflectionName(null);
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName1()
+		{
+			ReflectionHelper.ParseReflectionName(string.Empty);
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName2()
+		{
+			ReflectionHelper.ParseReflectionName("`");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName3()
+		{
+			ReflectionHelper.ParseReflectionName("``");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName4()
+		{
+			ReflectionHelper.ParseReflectionName("System.Action`A");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName5()
+		{
+			ReflectionHelper.ParseReflectionName("System.Environment+");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName5b()
+		{
+			ReflectionHelper.ParseReflectionName("System.Environment+`");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName6()
+		{
+			ReflectionHelper.ParseReflectionName("System.Int32[");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName7()
+		{
+			ReflectionHelper.ParseReflectionName("System.Int32[`]");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName8()
+		{
+			ReflectionHelper.ParseReflectionName("System.Int32[,");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName9()
+		{
+			ReflectionHelper.ParseReflectionName("System.Int32]");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName10()
+		{
+			ReflectionHelper.ParseReflectionName("System.Int32*a");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName11()
+		{
+			ReflectionHelper.ParseReflectionName("System.Action`1[[]]");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName12()
+		{
+			ReflectionHelper.ParseReflectionName("System.Action`1[[System.Int32]a]");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName13()
+		{
+			ReflectionHelper.ParseReflectionName("System.Action`1[[System.Int32],]");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName14()
+		{
+			ReflectionHelper.ParseReflectionName("System.Action`1[[System.Int32]");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName15()
+		{
+			ReflectionHelper.ParseReflectionName("System.Action`1[[System.Int32");
+		}
+		
+		[Test, ExpectedException(typeof(ReflectionNameParseException))]
+		public void ParseInvalidReflectionName16()
+		{
+			ReflectionHelper.ParseReflectionName("System.Action`1[[System.Int32],[System.String");
 		}
 	}
 }

ICSharpCode.NRefactory.Tests/Util/CSharpPrimitiveCastTests.cs

@@ -0,0 +1,68 @@
+// Copyright (c) 2010 AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under MIT X11 license (for details please see \doc\license.txt)
+
+using System;
+using NUnit.Framework;
+
+namespace ICSharpCode.NRefactory.Util
+{
+	[TestFixture]
+	public class CSharpPrimitiveCastTests
+	{
+		// I know, these tests aren't really clever, more of a way to fake code coverage...
+		// Well, at least they should ensure the 'tables' in CSharpPrimitiveCast don't contain any typos.
+		
+		[Test]
+		public void FloatToInteger()
+		{
+			for (int checkedMode = 0; checkedMode < 2; checkedMode++) {
+				for (TypeCode to = TypeCode.Char; to <= TypeCode.UInt64; to++) {
+					object val = CSharpPrimitiveCast.Cast(to, 3.9f, checkedMode == 1);
+					Assert.AreEqual(to, Type.GetTypeCode(val.GetType()));
+					Assert.AreEqual(3, Convert.ToInt64(val));
+				}
+			}
+		}
+		
+		[Test]
+		public void DoubleToInteger()
+		{
+			for (int checkedMode = 0; checkedMode < 2; checkedMode++) {
+				for (TypeCode to = TypeCode.Char; to <= TypeCode.UInt64; to++) {
+					object val = CSharpPrimitiveCast.Cast(to, 3.9, checkedMode == 1);
+					Assert.AreEqual(to, Type.GetTypeCode(val.GetType()));
+					Assert.AreEqual(3, Convert.ToInt64(val));
+				}
+			}
+		}
+		
+		[Test]
+		public void DecimalToInteger()
+		{
+			for (int checkedMode = 0; checkedMode < 2; checkedMode++) {
+				for (TypeCode to = TypeCode.Char; to <= TypeCode.UInt64; to++) {
+					object val = CSharpPrimitiveCast.Cast(to, 3.9m, checkedMode == 1);
+					Assert.AreEqual(to, Type.GetTypeCode(val.GetType()));
+					Assert.AreEqual(3, Convert.ToInt64(val));
+				}
+			}
+		}
+		
+		[Test]
+		public void IntegerToInteger()
+		{
+			for (int checkedMode = 0; checkedMode < 2; checkedMode++) {
+				for (TypeCode to = TypeCode.Char; to <= TypeCode.UInt64; to++) {
+					for (TypeCode to2 = TypeCode.Char; to2 <= TypeCode.Decimal; to2++) {
+						object val = CSharpPrimitiveCast.Cast(to, 3, checkedMode == 1);
+						Assert.AreEqual(to, Type.GetTypeCode(val.GetType()));
+						Assert.AreEqual(3, Convert.ToInt64(val));
+						object val2 = CSharpPrimitiveCast.Cast(to2, val, checkedMode == 1);
+						Assert.AreEqual(to2, Type.GetTypeCode(val2.GetType()));
+						Assert.AreEqual(3, Convert.ToInt64(val2));
+					}
+				}
+			}
+		}
+	}
+}

ICSharpCode.NRefactory/CSharp/Resolver/CSharpResolver.cs

@@ -381,7 +381,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			{
 				this.baseMethod = baseMethod;
 				this.ReturnType = NullableType.Create(baseMethod.ReturnType);
-				this.Parameters.Add(new DefaultParameter(NullableType.Create(baseMethod.Parameters[0].Type), string.Empty));
+				this.Parameters.Add(MakeNullableParameter(baseMethod.Parameters[0]));
 			}
 			
 			public override object Invoke(CSharpResolver resolver, object input)
@@ -453,23 +453,24 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			if (lhs.Type == SharedTypes.Dynamic || rhs.Type == SharedTypes.Dynamic)
 				return DynamicResult;
 			
-			// Handle logical and/or exactly as bitwise and/or:
-			// - If the user overloads a bitwise operator, that implicitly creates the corresponding logical operator.
-			// - If both inputs are compile-time constants, it doesn't matter that we don't short-circuit.
-			// - If inputs aren't compile-time constants, we don't evaluate anything, so again it doesn't matter that we don't short-circuit
-			if (op == BinaryOperatorType.LogicalAnd) {
-				op = BinaryOperatorType.BitwiseAnd;
-			} else if (op == BinaryOperatorType.LogicalOr) {
-				op = BinaryOperatorType.BitwiseOr;
-			} else if (op == BinaryOperatorType.NullCoalescing) {
-				// null coalescing operator is not overloadable and needs to be handled separately
-				return ResolveNullCoalescingOperator(lhs, rhs);
-			}
-			
 			// C# 4.0 spec: §7.3.4 Binary operator overload resolution
 			string overloadableOperatorName = GetOverloadableOperatorName(op);
 			if (overloadableOperatorName == null) {
-				throw new ArgumentException("Invalid value for BinaryOperatorType", "op");
+				
+				// Handle logical and/or exactly as bitwise and/or:
+				// - If the user overloads a bitwise operator, that implicitly creates the corresponding logical operator.
+				// - If both inputs are compile-time constants, it doesn't matter that we don't short-circuit.
+				// - If inputs aren't compile-time constants, we don't evaluate anything, so again it doesn't matter that we don't short-circuit
+				if (op == BinaryOperatorType.LogicalAnd) {
+					overloadableOperatorName = GetOverloadableOperatorName(BinaryOperatorType.BitwiseAnd);
+				} else if (op == BinaryOperatorType.LogicalOr) {
+					overloadableOperatorName = GetOverloadableOperatorName(BinaryOperatorType.BitwiseOr);
+				} else if (op == BinaryOperatorType.NullCoalescing) {
+					// null coalescing operator is not overloadable and needs to be handled separately
+					return ResolveNullCoalescingOperator(lhs, rhs);
+				} else {
+					throw new ArgumentException("Invalid value for BinaryOperatorType", "op");
+				}
 			}
 			
 			// If the type is nullable, get the underlying type:
@@ -626,6 +627,12 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 						}
 					}
 					break;
+				case BinaryOperatorType.LogicalAnd:
+					methodGroup = logicalAndOperator;
+					break;
+				case BinaryOperatorType.LogicalOr:
+					methodGroup = logicalOrOperator;
+					break;
 				default:
 					throw new InvalidOperationException();
 			}
@@ -896,10 +903,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			
 			public override object Invoke(CSharpResolver resolver, object lhs, object rhs)
 			{
-				if (lhs == null || rhs == null)
+				throw new NotSupportedException(); // cannot use nullables at compile time
-					return null;
-				else
-					return baseMethod.Invoke(resolver, lhs, rhs);
 			}
 			
 			public IList<IParameter> NonLiftedParameters {
@@ -1161,36 +1165,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			
 			public override OperatorMethod Lift()
 			{
-				return new LiftedRelationalOperatorMethod(this);
+				return new LiftedBinaryOperatorMethod(this);
-			}
-		}
-		
-		sealed class LiftedRelationalOperatorMethod : BinaryOperatorMethod, OverloadResolution.ILiftedOperator
-		{
-			readonly BinaryOperatorMethod baseMethod;
-			
-			public LiftedRelationalOperatorMethod(BinaryOperatorMethod baseMethod)
-			{
-				this.baseMethod = baseMethod;
-				this.ReturnType = baseMethod.ReturnType;
-				this.Parameters.Add(MakeNullableParameter(baseMethod.Parameters[0]));
-				this.Parameters.Add(MakeNullableParameter(baseMethod.Parameters[1]));
-			}
-			
-			public override bool CanEvaluateAtCompileTime {
-				get { return false; }
-			}
-			
-			public override object Invoke(CSharpResolver resolver, object lhs, object rhs)
-			{
-				if (lhs == null || rhs == null)
-					return false;
-				else
-					return baseMethod.Invoke(resolver, lhs, rhs);
-			}
-			
-			public IList<IParameter> NonLiftedParameters {
-				get { return baseMethod.Parameters; }
 			}
 		}
 		
@@ -1236,22 +1211,30 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		#endregion
 		
 		#region Bitwise operators
+		static readonly OperatorMethod[] logicalAndOperator = {
+			new LambdaBinaryOperatorMethod<bool, bool>  ((a, b) => a & b)
+		};
+		
 		static readonly OperatorMethod[] bitwiseAndOperators = Lift(
 			new LambdaBinaryOperatorMethod<int, int>    ((a, b) => a & b),
 			new LambdaBinaryOperatorMethod<uint, uint>  ((a, b) => a & b),
 			new LambdaBinaryOperatorMethod<long, long>  ((a, b) => a & b),
 			new LambdaBinaryOperatorMethod<ulong, ulong>((a, b) => a & b),
-			new LambdaBinaryOperatorMethod<bool, bool>  ((a, b) => a & b)
+			logicalAndOperator[0]
 		);
 		
+		static readonly OperatorMethod[] logicalOrOperator = {
+			new LambdaBinaryOperatorMethod<bool, bool>  ((a, b) => a | b)
+		};
+		
 		static readonly OperatorMethod[] bitwiseOrOperators = Lift(
 			new LambdaBinaryOperatorMethod<int, int>    ((a, b) => a | b),
 			new LambdaBinaryOperatorMethod<uint, uint>  ((a, b) => a | b),
 			new LambdaBinaryOperatorMethod<long, long>  ((a, b) => a | b),
 			new LambdaBinaryOperatorMethod<ulong, ulong>((a, b) => a | b),
-			new LambdaBinaryOperatorMethod<bool, bool>  ((a, b) => a | b)
+			logicalOrOperator[0]
 		);
-		// Note: the logic for the lifted bool? and bool? is wrong;
+		// Note: the logic for the lifted bool? bitwise operators is wrong;
 		// we produce "true | null" = "null" when it should be true. However, this is irrelevant
 		// because bool? cannot be a compile-time type.
 		

ICSharpCode.NRefactory/CSharp/Resolver/MemberLookup.cs

@@ -0,0 +1,36 @@
+// Copyright (c) 2010 AlphaSierraPapa for the SharpDevelop Team (for details please see \doc\copyright.txt)
+// This code is distributed under MIT X11 license (for details please see \doc\license.txt)
+
+using System;
+using ICSharpCode.NRefactory.TypeSystem;
+
+namespace ICSharpCode.NRefactory.CSharp.Resolver
+{
+	/// <summary>
+	/// Implementation of member lookup (C# 4.0 spec, §7.4).
+	/// </summary>
+	public class MemberLookup
+	{
+		ITypeResolveContext context;
+		
+		public MemberLookup(ITypeResolveContext context)
+		{
+			if (context == null)
+				throw new ArgumentNullException("context");
+			this.context = context;
+		}
+		
+		/// <summary>
+		/// Gets whether the member is considered to be invocable.
+		/// </summary>
+		public bool IsInvocable(IMember member)
+		{
+			if (member is IEvent || member is IMethod)
+				return true;
+			if (member.ReturnType == SharedTypes.Dynamic)
+				return true;
+			return member.ReturnType.Resolve(context).IsDelegate();
+		}
+		
+	}
+}

ICSharpCode.NRefactory/CSharp/Resolver/OverloadResolution.cs

@@ -77,7 +77,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		ResolveResult[] arguments;
 		string[] argumentNames;
 		Conversions conversions;
-		List<Candidate> candidates = new List<Candidate>();
+		//List<Candidate> candidates = new List<Candidate>();
 		Candidate bestCandidate;
 		Candidate bestCandidateAmbiguousWith;
 		
@@ -107,14 +107,14 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 			
 			Candidate c = new Candidate(member, false);
 			if (CalculateCandidate(c)) {
-				candidates.Add(c);
+				//candidates.Add(c);
 			}
 			
 			if (member.Parameters.Count > 0 && member.Parameters[member.Parameters.Count - 1].IsParams) {
 				Candidate expandedCandidate = new Candidate(member, true);
 				// consider expanded form only if it isn't obviously wrong
 				if (CalculateCandidate(expandedCandidate)) {
-					candidates.Add(expandedCandidate);
+					//candidates.Add(expandedCandidate);
 					
 					if (expandedCandidate.ErrorCount < c.ErrorCount)
 						return expandedCandidate.Errors;
@@ -144,7 +144,7 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 				if (candidate.IsExpandedForm && i == candidate.Parameters.Count - 1) {
 					ArrayType arrayType = type as ArrayType;
 					if (arrayType != null && arrayType.Dimensions == 1)
-						type = arrayType;
+						type = arrayType.ElementType;
 					else
 						return false; // error: cannot unpack params-array. abort considering the expanded form for this candidate
 				}
@@ -406,5 +406,13 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 		public IParameterizedMember BestCandidateAmbiguousWith {
 			get { return bestCandidateAmbiguousWith != null ? bestCandidateAmbiguousWith.Member : null; }
 		}
+		
+		public bool BestCandidateIsExpandedForm {
+			get { return bestCandidate != null ? bestCandidate.IsExpandedForm : false; }
+		}
+		
+		public bool IsAmbiguous {
+			get { return bestCandidateAmbiguousWith != null; }
+		}
 	}
 }

ICSharpCode.NRefactory/CSharp/Resolver/OverloadResolutionErrors.cs

@@ -9,15 +9,18 @@ namespace ICSharpCode.NRefactory.CSharp.Resolver
 	public enum OverloadResolutionErrors
 	{
 		None = 0,
-		
 		/// <summary>
 		/// Too many positional arguments (some could not be mapped to any parameter).
 		/// </summary>
-		TooManyPositionalArguments = 0x0002,
+		TooManyPositionalArguments = 0x0001,
 		/// <summary>
 		/// A named argument could not be mapped to any parameter
 		/// </summary>
-		NoParameterFoundForNamedArgument = 0x0004,
+		NoParameterFoundForNamedArgument = 0x0002,
+		/// <summary>
+		/// Type inference failed for a generic method.
+		/// </summary>
+		TypeInferenceFailed = 0x0004,
 		/// <summary>
 		/// No argument was mapped to a non-optional parameter
 		/// </summary>

ICSharpCode.NRefactory/ICSharpCode.NRefactory.csproj

@@ -144,6 +144,7 @@
     <Compile Include="CSharp\Resolver\Conversions.cs" />
     <Compile Include="CSharp\Resolver\CSharpResolver.cs" />
     <Compile Include="CSharp\Resolver\ErrorResolveResult.cs" />
+    <Compile Include="CSharp\Resolver\MemberLookup.cs" />
     <Compile Include="CSharp\Resolver\OverloadResolution.cs" />
     <Compile Include="CSharp\Resolver\OverloadResolutionErrors.cs" />
     <Compile Include="CSharp\Resolver\ResolveResult.cs" />

ICSharpCode.NRefactory/TypeSystem/ArrayType.cs

@@ -12,9 +12,9 @@ namespace ICSharpCode.NRefactory.TypeSystem
 	/// </summary>
 	public class ArrayType : TypeWithElementType
 	{
-		int dimensions;
+		readonly int dimensions;
 		
-		public ArrayType(IType elementType, int dimensions) : base(elementType)
+		public ArrayType(IType elementType, int dimensions = 1) : base(elementType)
 		{
 			if (dimensions <= 0)
 				throw new ArgumentOutOfRangeException("dimensions", dimensions, "dimensions must be positive");
@@ -27,10 +27,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		
 		public override string NameSuffix {
 			get {
-				if (dimensions == 0)
+				return "[" + new string(',', dimensions-1) + "]";
-					return "[]";
-				else
-					return "[" + new string(',', dimensions-1) + "]";
 			}
 		}
 		
@@ -83,7 +80,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		ITypeReference elementType;
 		int dimensions;
 		
-		public ArrayTypeReference(ITypeReference elementType, int dimensions)
+		public ArrayTypeReference(ITypeReference elementType, int dimensions = 1)
 		{
 			if (elementType == null)
 				throw new ArgumentNullException("elementType");

ICSharpCode.NRefactory/TypeSystem/ExtensionMethods.cs

@@ -125,6 +125,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		/// <summary>
 		/// Gets whether the type is an delegate type.
 		/// </summary>
+		/// <remarks>This method returns <c>false</c> for System.Delegate itself</remarks>
 		public static bool IsDelegate(this IType type)
 		{
 			if (type == null)
@@ -132,6 +133,26 @@ namespace ICSharpCode.NRefactory.TypeSystem
 			ITypeDefinition def = type.GetDefinition();
 			return def != null && def.ClassType == ClassType.Delegate;
 		}
+		
+		/// <summary>
+		/// Gets the invoke method for a delegate type.
+		/// </summary>
+		/// <remarks>
+		/// Returns null if the type is not a delegate type; or if the invoke method could not be found.
+		/// </remarks>
+		public static IMethod GetDelegateInvokeMethod(this IType type)
+		{
+			if (type == null)
+				throw new ArgumentNullException("type");
+			ITypeDefinition def = type.GetDefinition();
+			if (def != null && def.ClassType == ClassType.Delegate) {
+				foreach (IMethod method in def.Methods) {
+					if (method.Name == "Invoke")
+						return method;
+				}
+			}
+			return null;
+		}
 		#endregion
 	}
 }

ICSharpCode.NRefactory/TypeSystem/INamedElement.cs

@@ -48,6 +48,10 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		/// <summary>
 		/// Gets the full reflection name of the element.
 		/// </summary>
+		/// <remarks>
+		/// For types, the reflection name can be parsed back into a ITypeReference by using
+		/// <see cref="ReflectionHelper.ParseReflectionName"/>.
+		/// </remarks>
 		/// <returns>
 		/// "System.Int32[]" for int[]<br/>
 		/// "System.Int32[][,]" for C# int[,][]<br/>

ICSharpCode.NRefactory/TypeSystem/IType.cs

@@ -40,12 +40,16 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		/// <summary>
 		/// Calls ITypeVisitor.Visit for this type.
 		/// </summary>
+		/// <returns>The return value of the ITypeVisitor.Visit call</returns>
 		IType AcceptVisitor(TypeVisitor visitor);
 		
 		/// <summary>
 		/// Calls ITypeVisitor.Visit for all children of this type, and reconstructs this type with the children based
-		/// by the return values of the visit calls.
+		/// on the return values of the visit calls.
 		/// </summary>
+		/// <returns>A copy of this type, with all children replaced by the return value of the corresponding visitor call.
+		/// If the visitor returned the original types for all children (or if there are no children), returns <c>this</c>.
+		/// </returns>
 		IType VisitChildren(TypeVisitor visitor);
 		
 		/// <summary>
@@ -59,9 +63,15 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		/// <remarks>
 		/// If the inner class is generic, this method produces <see cref="ParameterizedType"/>s that
 		/// parameterize each nested class with its own type parameters.
+		/// TODO: does this make sense? ConstructedType needs it, but maybe it would be better to build
+		/// those self-parameterized types only in ConstructedType?
 		/// </remarks>
 		IEnumerable<IType> GetNestedTypes(ITypeResolveContext context);
 		
+		// TODO: PERF maybe give GetMethods/GetProperties/etc a filter predicate
+		// that allows filtering the members pre-substitution?
+		// that could dramatically decrease the number of substitutions we have to perform
+		
 		/// <summary>
 		/// Gets all methods that can be called on this return type.
 		/// </summary>

ICSharpCode.NRefactory/TypeSystem/Implementation/GetClassTypeReference.cs

@@ -25,7 +25,7 @@ namespace ICSharpCode.NRefactory.TypeSystem.Implementation
 		{
 			if (context == null)
 				throw new ArgumentNullException("context");
-			// TODO: caching idea: if these lookups are a performance problem and the same GetClassTypeReference
+			// TODO: PERF: caching idea: if these lookups are a performance problem and the same GetClassTypeReference
 			// is asked to resolve lots of times in a row, try the following:
 			// Give ITypeResolveContext a property "object CacheToken { get; }" which is non-null if the
 			// context supports caching, and returns the same object only as long as the context is unchanged.

ICSharpCode.NRefactory/TypeSystem/ReflectionHelper.cs

@@ -227,8 +227,15 @@ namespace ICSharpCode.NRefactory.TypeSystem
 		/// <summary>
 		/// Parses a reflection name into a type reference.
 		/// </summary>
+		/// <param name="reflectionTypeName">The reflection name of the type.</param>
+		/// <param name="parentEntity">Parent entity, used to find the type parameters for open types.
+		/// If no entity is provided, type parameters are converted to <see cref="SharedTypes.UnknownType"/>.</param>
+		/// <exception cref="ReflectionNameParseException">The syntax of the reflection type name is invalid</exception>
+		/// <returns>A type reference that represents the reflection name.</returns>
 		public static ITypeReference ParseReflectionName(string reflectionTypeName, IEntity parentEntity = null)
 		{
+			if (reflectionTypeName == null)
+				throw new ArgumentNullException("reflectionTypeName");
 			int pos = 0;
 			ITypeReference r = ParseReflectionName(reflectionTypeName, ref pos, parentEntity);
 			if (pos < reflectionTypeName.Length)
@@ -343,7 +350,7 @@ namespace ICSharpCode.NRefactory.TypeSystem
 								pos++; // end of array
 								reference = new ArrayTypeReference(reference, dimensions);
 							} else {
-								throw new ReflectionNameParseException(pos, "Expected array modifier");
+								throw new ReflectionNameParseException(pos, "Invalid array modifier");
 							}
 						}
 						break;

README

@@ -28,7 +28,7 @@ Null-Object pattern:
 	this allows code completion to work in the presence of minor semantic errors.
 
 FAQ:
-Q:	What is the difference between a type and a type definition?
+Q:	What is the difference between types and type definitions?
 
 A:	Basically, a type (IType) is any type in the .NET type system:
 		- an array (ArrayType)
@@ -45,7 +45,8 @@ A:	Basically, a type (IType) is any type in the .NET type system:
 	method. The GetDefinition() method will also return the underlying ITypeDefinition if given a parameterized type,
 	so "List<int>".GetDefinition() is "List<T>".
 
-Q:	What is the difference betweent type references and types?
+
+Q:	What is the difference between types and type references?
 	I've seen lots of duplicated classes (ArrayType vs. ArrayTypeReference, etc.)
 	
 	NRefactory has the concept of the "project content": every assembly/project is stored independently from other assemblies/projects.
@@ -62,6 +63,10 @@ Q:	What is the difference betweent type references and types?
 	Note that every type can also be used as type reference - the IType interface derives from ITypeReference.
 	Every IType simply returns itself when the Resolve()-method is called.
 	Types are often directly used as references when source and target of the reference are within the same assembly.
+	
+	Because an ArrayType must have an IType as element type, we also need the ArrayTypeReference to represent an array
+	of a type that's not yet resolved. When resolved, the ArrayTypeReference produces an array type:
+		new ArrayTypeReference(r).Resolve(context) = new ArrayType(r.Resolve(context))
 
 A:	If you've previously used the .NET Reflection API, the concept of type references is new to you.
 
@@ -81,6 +86,7 @@ A:	Please use:
 	The approach suggested above will return SharedTypes.UnknownType when the type cannot be resolved, so you
 	don't run into the risk of getting NullReferenceExceptions.
 
+
 Q:	Is it thread-safe?
 
 A:	This question is a bit difficult to answer.
@@ -124,3 +130,8 @@ A:	This question is a bit difficult to answer.
 	The return value "syncContext" can then be used to access the type resolve context without further synchronization overhead.
 	Once the return value is disposed, the read-locks are released.
 
+
+Q:	What format do the .ToString() methods use?
+
+A:	They don't use any particular format. They're merely intended as a debugging aid.
+	Currently .ToString() usually matches .ReflectionName, but that may change in the future.