Jurassic.Compiler.BinaryExpression.GenerateInstanceOf C# (CSharp) Method

        private void GenerateInstanceOf(ILGenerator generator, OptimizationInfo optimizationInfo)
        {
            // Emit the left-hand side expression and convert it to an object.
            this.Left.GenerateCode(generator, optimizationInfo);
            EmitConversion.ToAny(generator, this.Left.ResultType);

            // Store the left-hand side expression in a temporary variable.
            var temp = generator.CreateTemporaryVariable(typeof(object));
            generator.StoreVariable(temp);

            // Emit the right-hand side expression.
            this.Right.GenerateCode(generator, optimizationInfo);
            EmitConversion.ToAny(generator, this.Right.ResultType);

            // Check the right-hand side is a function - if not, throw an exception.
            generator.Duplicate();
            generator.IsInstance(typeof(Library.FunctionInstance));
            var endOfTypeCheck = generator.CreateLabel();
            generator.BranchIfNotNull(endOfTypeCheck);

            // Throw an nicely formatted exception.
            var rightValue = generator.CreateTemporaryVariable(typeof(object));
            generator.StoreVariable(rightValue);
            EmitHelpers.LoadScriptEngine(generator);
            generator.LoadInt32((int)ErrorType.TypeError);
            generator.LoadString("The instanceof operator expected a function, but found '{0}' instead");
            generator.LoadInt32(1);
            generator.NewArray(typeof(object));
            generator.Duplicate();
            generator.LoadInt32(0);
            generator.LoadVariable(rightValue);
            generator.Call(ReflectionHelpers.TypeUtilities_TypeOf);
            generator.StoreArrayElement(typeof(object));
            generator.Call(ReflectionHelpers.String_Format);
            generator.LoadInt32(optimizationInfo.SourceSpan.StartLine);
            generator.LoadStringOrNull(optimizationInfo.Source.Path);
            generator.LoadStringOrNull(optimizationInfo.FunctionName);
            generator.NewObject(ReflectionHelpers.JavaScriptException_Constructor_Error);
            generator.Throw();
            generator.DefineLabelPosition(endOfTypeCheck);
            generator.ReleaseTemporaryVariable(rightValue);

            // Load the left-hand side expression from the temporary variable.
            generator.LoadVariable(temp);

            // Call FunctionInstance.HasInstance(object)
            generator.Call(ReflectionHelpers.FunctionInstance_HasInstance);

            // Allow the temporary variable to be reused.
            generator.ReleaseTemporaryVariable(temp);
        }