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AspClassic.VBScript/Binders/VBScriptUnaryOperationBinder.cs

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+using System;
+using System.Collections.Generic;
+//using System.Text;
+using System.Reflection;
+using System.Dynamic;
+#if USE35
+using AspClassic.Scripting.Ast;
+#else
+using System.Linq.Expressions;
+#endif
+using Dlrsoft.VBScript.Runtime;
+using Debug = System.Diagnostics.Debug;
+
+namespace Dlrsoft.VBScript.Binders
+{
+    public class VBScriptUnaryOperationBinder : UnaryOperationBinder
+    {
+        public VBScriptUnaryOperationBinder(ExpressionType operation)
+            : base(operation)
+        {
+        }
+
+        public override DynamicMetaObject FallbackUnaryOperation(
+                   DynamicMetaObject target, DynamicMetaObject errorSuggestion)
+        {
+            // Defer if any object has no value so that we evaulate their
+            // Expressions and nest a CallSite for the InvokeMember.
+            if (!target.HasValue)
+            {
+                return Defer(target);
+            }
+
+            var restrictions = target.Restrictions;
+            if (target.Value == null)
+            {
+                restrictions = restrictions.Merge(
+                    BindingRestrictions.GetInstanceRestriction(target.Expression, null)
+                );
+            }
+            else
+            {
+                restrictions = restrictions.Merge(
+                    BindingRestrictions.GetTypeRestriction(
+                        target.Expression, target.LimitType));
+            }
+
+            if (this.Operation == ExpressionType.Not)
+            {
+                if (target.LimitType != typeof(bool))
+                {
+                    MethodInfo mi = typeof(HelperFunctions).GetMethod("Not");
+
+                    return new DynamicMetaObject(
+                       RuntimeHelpers.EnsureObjectResult(
+                         Expression.Call(mi, target.Expression)
+                       ),
+                       restrictions);
+                }
+            }
+            else if (this.Operation == ExpressionType.Negate)
+            {
+                if (!target.LimitType.IsPrimitive || target.LimitType == typeof(bool))
+                {
+                    MethodInfo mi = typeof(HelperFunctions).GetMethod("Negate");
+
+                    return new DynamicMetaObject(
+                       RuntimeHelpers.EnsureObjectResult(
+                         Expression.Call(mi, target.Expression)
+                       ),
+                       restrictions);
+                }
+            }
+
+            return new DynamicMetaObject(
+                RuntimeHelpers.EnsureObjectResult(
+                  Expression.MakeUnary(
+                    this.Operation,
+                    Expression.Convert(target.Expression, target.LimitType),
+                    target.LimitType)),
+                restrictions);
+        }
+    }
+}