Separate decode and execute steps

UIX/Microsoft/Iris/Debug/Data/InterpreterEntry.cs

@@ -1,5 +1,4 @@
-using Microsoft.Iris.Markup;
-using System;
+using System;
 using System.Collections.Generic;
 using System.Text;
 
@@ -15,27 +14,26 @@ public class InterpreterEntry : IComparable<InterpreterEntry>
         Instruction = instruction;
     }
 
-    public InterpreterInstruction Instruction { get; }
+    public InterpreterInstruction Instruction { get; set; }
 
     public List<InterpreterObject> Parameters { get; } = new();
 
     public List<InterpreterObject> ReturnValues { get; } = new();
 
-    public string InstructionString => ToInstructionString();
-
     public override string ToString()
     {
-        StringBuilder sb = new($"[{LoadUri} @ 0x{Offset:X}] {OpCode}({string.Join(", ", Parameters)})");
+        StringBuilder sb = new($"[{Instruction.LoadUri} @ 0x{Instruction.Offset:X}] " +
+            $"{Instruction.OpCode}({string.Join(", ", Parameters)})");
 
-        if (ReturnValues.Count > 0)
-        {
-            sb.Append(" -> ");
+        if (ReturnValues.Count <= 0)
+            return sb.ToString();
+        
+        sb.Append(" -> ");
 
-            if (ReturnValues.Count == 1)
-                sb.Append(ReturnValues[0]);
-            else
-                sb.Append($"[{string.Join(", ", ReturnValues)}]");
-        }
+        if (ReturnValues.Count == 1)
+            sb.Append(ReturnValues[0]);
+        else
+            sb.Append($"[{string.Join(", ", ReturnValues)}]");
 
         return sb.ToString();
     }

UIX/Microsoft/Iris/Debug/Data/InterpreterInstruction.cs

@@ -1,11 +1,14 @@
 using Microsoft.Iris.Markup;
 using System;
+using System.Collections.Generic;
 
 namespace Microsoft.Iris.Debug.Data;
 
 [Serializable]
 public class InterpreterInstruction : IComparable<InterpreterInstruction>
 {
+    public InterpreterInstruction() { }
+
     public InterpreterInstruction(OpCode opCode, uint offset, string loadUri)
     {
         OpCode = opCode;
@@ -19,11 +22,15 @@ public class InterpreterInstruction : IComparable<InterpreterInstruction>
 
     public string LoadUri { get; set; }
 
+    public List<object> Operands { get; } = new();
+
     public int CompareTo(InterpreterInstruction other)
     {
-        int stringCmp = LoadUri.CompareTo(other.LoadUri);
+        var stringCmp = string.Compare(LoadUri, other.LoadUri, StringComparison.Ordinal);
         return stringCmp != 0
             ? stringCmp
             : Offset.CompareTo(other.Offset);
     }
+
+    public override string ToString() => $"[0x{Offset:X}] {OpCode} {string.Join(", ", Operands)}";
 }

UIX/Microsoft/Iris/Debug/DebuggerMessageType.cs

@@ -4,7 +4,8 @@ public enum DebuggerMessageType : int
 {
     Null = 0,
 
-    InterpreterOpCode,
+    InterpreterDecode,
+    InterpreterExecute,
     DispatcherStep,
 
     UpdateBreakpoint,

UIX/Microsoft/Iris/Debug/IDebuggerClient.cs

@@ -15,9 +15,14 @@ public interface IDebuggerClient
     event Action<InterpreterCommand> InterpreterStateChanged;
 
     /// <summary>
-    /// Fired when the UIX interpreter steps forward.
+    /// Fired when the UIX interpreter decodes an instruction.
     /// </summary>
-    event EventHandler<InterpreterEntry> InterpreterStep;
+    event EventHandler<InterpreterInstruction> InterpreterDecode;
+
+    /// <summary>
+    /// Fired when the UIX interpreter executes an instruction.
+    /// </summary>
+    event EventHandler<InterpreterEntry> InterpreterExecute;
 
     /// <summary>
     /// Fired when the UIX dispatcher executes another call from the queue.

UIX/Microsoft/Iris/Debug/IDebuggerServer.cs

@@ -7,10 +7,16 @@ internal interface IDebuggerServer
     InterpreterCommand DebuggerCommand { get; set; }
 
     /// <summary>
-    /// Logs the context, opcode, and arguments of an instruction
+    /// Logs the context, opcode, and operands of an instruction
+    /// decoded by <c>Microsoft.Iris.Markup.Interpreter</c>.
+    /// </summary>
+    void LogInterpreterDecode(object context, InterpreterInstruction instruction);
+
+    /// <summary>
+    /// Logs the context, opcode, arguments, and results of an instruction
     /// executed by <c>Microsoft.Iris.Markup.Interpreter</c>.
     /// </summary>
-    void LogInterpreterOpCode(object context, InterpreterEntry entry);
+    void LogInterpreterExecute(object context, InterpreterEntry entry);
 
     /// <summary>
     /// Logs the string representation of a dispatcher step.

UIX/Microsoft/Iris/Debug/SystemNet/NetDebuggerClient.cs

@@ -27,7 +27,8 @@ public class NetDebuggerClient : IDebuggerClient, IDisposable
         }
     }
 
-    public event EventHandler<InterpreterEntry> InterpreterStep;
+    public event EventHandler<InterpreterInstruction> InterpreterDecode;
+    public event EventHandler<InterpreterEntry> InterpreterExecute;
     public event Action<string> DispatcherStep;
     public event Action<InterpreterCommand> InterpreterStateChanged;
 
@@ -75,9 +76,14 @@ public class NetDebuggerClient : IDebuggerClient, IDisposable
 
             switch (frame.Type)
             {
-                case DebuggerMessageType.InterpreterOpCode:
-                    var entry = frame.DeserializeData<InterpreterEntry>(_formatter);
-                    InterpreterStep?.Invoke(this, entry);
+                case DebuggerMessageType.InterpreterDecode:
+                    var decEntry = frame.DeserializeData<InterpreterInstruction>(_formatter);
+                    InterpreterDecode?.Invoke(this, decEntry);
+                    break;
+                
+                case DebuggerMessageType.InterpreterExecute:
+                    var execEntry = frame.DeserializeData<InterpreterEntry>(_formatter);
+                    InterpreterExecute?.Invoke(this, execEntry);
                     break;
 
                 case DebuggerMessageType.DispatcherStep:
@@ -91,7 +97,7 @@ public class NetDebuggerClient : IDebuggerClient, IDisposable
                     break;
 
                 default:
-                    Trace.WriteLine(TraceCategory.MarkupDebug, "Recieved unknown debugger message of type '{0}'.", frame.Type);
+                    Trace.WriteLine(TraceCategory.MarkupDebug, "Received unknown debugger message of type '{0}'.", frame.Type);
                     break;
             }
         }

UIX/Microsoft/Iris/Debug/SystemNet/NetDebuggerServer.cs

@@ -49,9 +49,14 @@ internal class NetDebuggerServer : IDebuggerServer, IDisposable
         Current = this;
     }
 
-    public void LogInterpreterOpCode(object context, InterpreterEntry entry)
+    public void LogInterpreterDecode(object context, InterpreterInstruction instruction)
     {
-        QueueDebuggerMessage(new(0, DebuggerMessageType.InterpreterOpCode, entry.Serialize(_formatter)));
+        QueueDebuggerMessage(new(0, DebuggerMessageType.InterpreterDecode, instruction.Serialize(_formatter)));
+    }
+
+    public void LogInterpreterExecute(object context, InterpreterEntry entry)
+    {
+        QueueDebuggerMessage(new(0, DebuggerMessageType.InterpreterExecute, entry.Serialize(_formatter)));
     }
 
     public void LogDispatcher(string message)