Flee

ExpressionElements/Root.cs

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+using System.Reflection.Emit;
+using Flee.ExpressionElements.Base;
+using Flee.InternalTypes;
+using Flee.PublicTypes;
+using Flee.Resources;
+
+namespace Flee.ExpressionElements
+{
+    internal class RootExpressionElement : ExpressionElement
+    {
+        private readonly ExpressionElement _myChild;
+        private readonly Type _myResultType;
+        public RootExpressionElement(ExpressionElement child, Type resultType)
+        {
+            _myChild = child;
+            _myResultType = resultType;
+            this.Validate();
+        }
+
+        public override void Emit(FleeILGenerator ilg, IServiceProvider services)
+        {
+            _myChild.Emit(ilg, services);
+            ImplicitConverter.EmitImplicitConvert(_myChild.ResultType, _myResultType, ilg);
+
+            ExpressionOptions options = (ExpressionOptions)services.GetService(typeof(ExpressionOptions));
+
+            if (options.IsGeneric == false)
+            {
+                ImplicitConverter.EmitImplicitConvert(_myResultType, typeof(object), ilg);
+            }
+
+            ilg.Emit(OpCodes.Ret);
+        }
+
+        private void Validate()
+        {
+            if (ImplicitConverter.EmitImplicitConvert(_myChild.ResultType, _myResultType, null) == false)
+            {
+                base.ThrowCompileException(CompileErrorResourceKeys.CannotConvertTypeToExpressionResult, CompileExceptionReason.TypeMismatch, _myChild.ResultType.Name, _myResultType.Name);
+            }
+        }
+
+        public override System.Type ResultType => typeof(object);
+    }
+}