Flee

ExpressionElements/Negate.cs

@@ -0,0 +1,56 @@
+using System.Reflection.Emit;
+using System.Reflection;
+using Flee.ExpressionElements.Base;
+using Flee.InternalTypes;
+
+namespace Flee.ExpressionElements
+{
+    internal class NegateElement : UnaryElement
+    {
+        public NegateElement()
+        {
+        }
+
+        protected override System.Type GetResultType(System.Type childType)
+        {
+            TypeCode tc = Type.GetTypeCode(childType);
+
+            MethodInfo mi = Utility.GetSimpleOverloadedOperator("UnaryNegation", childType, null);
+            if ((mi != null))
+            {
+                return mi.ReturnType;
+            }
+
+            switch (tc)
+            {
+                case TypeCode.Single:
+                case TypeCode.Double:
+                case TypeCode.Int32:
+                case TypeCode.Int64:
+                    return childType;
+                case TypeCode.UInt32:
+                    return typeof(Int64);
+                default:
+                    return null;
+            }
+        }
+
+        public override void Emit(FleeILGenerator ilg, IServiceProvider services)
+        {
+            Type resultType = this.ResultType;
+            MyChild.Emit(ilg, services);
+            ImplicitConverter.EmitImplicitConvert(MyChild.ResultType, resultType, ilg);
+
+            MethodInfo mi = Utility.GetSimpleOverloadedOperator("UnaryNegation", resultType, null);
+
+            if (mi == null)
+            {
+                ilg.Emit(OpCodes.Neg);
+            }
+            else
+            {
+                ilg.Emit(OpCodes.Call, mi);
+            }
+        }
+    }
+}