Improved the diagnostic system with helper methods to actually emit diagnostics.

src/Generator/Diagnostics.cs

@@ -2,6 +2,11 @@
 
 namespace Cxxi
 {
+    public enum DiagnosticId
+    {
+        InvalidOperatorOverload
+    }
+
     public enum DiagnosticKind
     {
         Message,
@@ -11,6 +16,7 @@ namespace Cxxi
 
     public struct DiagnosticInfo
     {
+        public DiagnosticKind Kind;
         public string Message;
         public string File;
         public int Line;
@@ -19,12 +25,51 @@ namespace Cxxi
 
     public interface IDiagnosticConsumer
     {
-        void Emit(DiagnosticKind kind, DiagnosticInfo info);
+        void Emit(DiagnosticInfo info);
+    }
+
+    public static class DiagnosticExtensions
+    {
+        public static void EmitMessage(this IDiagnosticConsumer consumer,
+            DiagnosticId id, string msg, params object[] args)
+        {
+            var diagInfo = new DiagnosticInfo
+                {
+                    Kind = DiagnosticKind.Message,
+                    Message = string.Format(msg, args)
+                };
+
+            consumer.Emit(diagInfo);
+        }
+
+        public static void EmitWarning(this IDiagnosticConsumer consumer,
+            DiagnosticId id, string msg, params object[] args)
+        {
+            var diagInfo = new DiagnosticInfo
+            {
+                Kind = DiagnosticKind.Warning,
+                Message = string.Format(msg, args)
+            };
+
+            consumer.Emit(diagInfo);
+        }
+
+        public static void EmitError(this IDiagnosticConsumer consumer,
+            DiagnosticId id, string msg, params object[] args)
+        {
+            var diagInfo = new DiagnosticInfo
+            {
+                Kind = DiagnosticKind.Error,
+                Message = string.Format(msg, args)
+            };
+
+            consumer.Emit(diagInfo);
+        }
     }
 
     public class TextDiagnosticPrinter : IDiagnosticConsumer
     {
-        public void Emit(DiagnosticKind kind, DiagnosticInfo info)
+        public void Emit(DiagnosticInfo info)
         {
             Console.WriteLine(info.Message);
         }