Added support of param arrays within constructors, in line with other…

… method invocations. (#199)

Fix #196

src/DynamicExpresso.Core/Parsing/Parser.cs

@@ -1077,15 +1077,21 @@ private Expression ParseNew()
 				ValidateToken(TokenId.OpenCurlyBracket, ErrorMessages.OpenCurlyBracketExpected);
 			}
 
-			var constructor = newType.GetConstructor(args.Select(p => p.Type).ToArray());
-			if (constructor == null)
+			var applicableConstructors = FindBestMethod(newType.GetConstructors(), args);
+			if (applicableConstructors.Length == 0)
 				throw CreateParseException(_token.pos, ErrorMessages.NoApplicableConstructor, newType);
 
+			if (applicableConstructors.Length > 1)
+				throw CreateParseException(_token.pos, ErrorMessages.AmbiguousConstructorInvocation, newType);
+
+			var constructor = applicableConstructors[0];
+			var newExpr = Expression.New((ConstructorInfo)constructor.MethodBase, constructor.PromotedParameters);
+
 			var memberBindings = new MemberBinding[0];
 			if (_token.id == TokenId.OpenCurlyBracket)
 				memberBindings = ParseObjectInitializer(newType);
 
-			return Expression.MemberInit(Expression.New(constructor, args), memberBindings);
+			return Expression.MemberInit(newExpr, memberBindings);
 		}
 
 		private MemberBinding[] ParseObjectInitializer(Type newType)

src/DynamicExpresso.Core/Resources/ErrorMessages.resx

@@ -261,4 +261,7 @@
   <data name="ParamsArrayTypeNotAnArray" xml:space="preserve">
     <value>Params array type is not an array, element not found</value>
   </data>
+  <data name="AmbiguousConstructorInvocation" xml:space="preserve">
+    <value>Ambiguous invocation of constructor in type '{0}'</value>
+  </data>
 </root>

test/DynamicExpresso.UnitTest/ConstructorTest.cs

@@ -133,11 +133,20 @@ public void Object_initializer_syntax_error()
 			Assert.Throws<ParseException>(() => target.Parse("new MyClass() {5}")); // no field name
 		}
 
+		[Test]
+		public void Ctor_params_array()
+		{
+			var target = new Interpreter();
+			target.Reference(typeof(MyClass));
+			Assert.AreEqual(new MyClass(6, 5, 4, 3).MyArr, target.Eval("new MyClass(6, 5, 4, 3).MyArr"));
+		}
+
 		private class MyClass
 		{
 			public int IntField;
 			public string StrProp { get; set; }
 			public int ReadOnlyProp { get; }
+			public int[] MyArr { get; set; }
 
 			public MyClass()
 			{
@@ -148,6 +157,11 @@ public MyClass(string strValue)
 				StrProp = strValue;
 			}
 
+			public MyClass(params int[] intValues)
+			{
+				MyArr = intValues;
+			}
+
 			public override bool Equals(object obj)
 			{
 				return Equals(obj as MyClass);