Expose ActionProbabilities list from RankingResponse

reinforcement_learning/bindings/cs/rl.net.cli/RLSimulator.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
+using System.Text;
 using Rl.Net;
 
 namespace Rl.Net.Cli {
@@ -11,6 +12,23 @@ public enum Topic : long
         MachineLearning
     }
 
+    internal static class RankingResponseExtensions
+    {
+        public static string ToDistributionString(this RankingResponse response)
+        {
+            StringBuilder stringBuilder = new StringBuilder("(");
+
+            foreach (ActionProbability actionProbability in response)
+            {
+                stringBuilder.Append($"[{actionProbability.ActionIndex}, {actionProbability.Probability}]");
+            }
+
+            stringBuilder.Append(')');
+
+            return stringBuilder.ToString();
+        }
+    }
+
     internal class RLSimulator
     {
         public static readonly Random RandomSource = new Random();
@@ -75,7 +93,7 @@ private void Step()
             // TODO: Record stats
             this.stats.Record(person, actionTopic, outcome);
 
-            Console.WriteLine($" {this.stats.TotalActions}, ctxt, {person.Id}, action, {actionTopic}, outcome, {outcome}, dist, {"" /*todo*/}, {this.stats.GetStats(person, actionTopic)}");
+            Console.WriteLine($" {this.stats.TotalActions}, ctxt, {person.Id}, action, {actionTopic}, outcome, {outcome}, dist, {responseContainer.ToDistributionString()}, {this.stats.GetStats(person, actionTopic)}");
         }
 
         private void SafeRaiseError(ApiStatus errorStatus)

reinforcement_learning/bindings/cs/rl.net.native/rl.net.ranking_response.cc

@@ -11,6 +11,16 @@ class ranking_enumerator_adapter
     {}
 
 public:
+    inline int check_current()
+    {
+        if (this->current != this->end)
+        {
+            return 1;
+        }
+
+        return 0;
+    }
+
     inline int move_next()
     {
         if ((this->current != this->end) &&
@@ -68,9 +78,14 @@ API void DeleteRankingEnumeratorAdapter(ranking_enumerator_adapter* adapter)
     delete adapter;
 }
 
+API int RankingEnumeratorInit(ranking_enumerator_adapter* adapter)
+{
+    return adapter->check_current();
+}
+
 API int RankingEnumeratorMoveNext(ranking_enumerator_adapter* adapter)
 {
-    return adapter->move_next();
+  return adapter->move_next();
 }
 
 API reinforcement_learning::action_prob GetRankingEnumeratorCurrent(ranking_enumerator_adapter* adapter)

reinforcement_learning/bindings/cs/rl.net.native/rl.net.ranking_response.h

@@ -24,6 +24,7 @@ extern "C" {
     API ranking_enumerator_adapter* CreateRankingEnumeratorAdapter(reinforcement_learning::ranking_response* ranking);
     API void DeleteRankingEnumeratorAdapter(ranking_enumerator_adapter* adapter);
 
+    API int RankingEnumeratorInit(ranking_enumerator_adapter* adapter);
     API int RankingEnumeratorMoveNext(ranking_enumerator_adapter* adapter);
     API reinforcement_learning::action_prob GetRankingEnumeratorCurrent(ranking_enumerator_adapter* adapter);
 }

reinforcement_learning/bindings/cs/rl.net/RankingResponse.cs

@@ -5,21 +5,21 @@
 using System.Runtime.InteropServices;
 
 using Rl.Net.Native;
+using System.Collections;
 
 namespace Rl.Net {
     [StructLayout(LayoutKind.Sequential)]
-    internal struct ActionProbability
+    public struct ActionProbability
     {
-        public UIntPtr ActionId; // If we expose this publicly, this will not be CLS-compliant
-                                 // No idea if that could cause issues going to .NET Core (probably
-                                 // not, but this is something we should check.), but having to do
-                                 // a conversion on every iteration feels very heavyweight. Can 
-                                 // we change this contract to be defined as the signed version of
-                                 // the pointer type?
-        public float Probability;
+        private UIntPtr actionIndex;
+        private float probability;
+
+        public long ActionIndex => (long)this.actionIndex.ToUInt64();
+
+        public float Probability => this.probability;
     }
 
-    public sealed class RankingResponse: NativeObject<RankingResponse>
+    public sealed class RankingResponse: NativeObject<RankingResponse>, IEnumerable<ActionProbability>
     {
         [DllImport("rl.net.native.dll")]
         private static extern IntPtr CreateRankingResponse();
@@ -63,9 +63,9 @@ public long Count
         }
 
         // TODO: Why does this method call, which seems like a "get" of a value, have an API status?
-        public bool TryGetChosenAction(out long action, ApiStatus status = null)
+        public bool TryGetChosenAction(out long actionIndex, ApiStatus status = null)
         {
-            action = -1;
+            actionIndex = -1;
             UIntPtr chosenAction;
             int result = GetRankingChosenAction(this.NativeHandle, out chosenAction, status.ToNativeHandleOrNullptr());
 
@@ -74,10 +74,20 @@ public bool TryGetChosenAction(out long action, ApiStatus status = null)
                 return false;
             }
 
-            action = (long)(chosenAction.ToUInt64());
+            actionIndex = (long)(chosenAction.ToUInt64());
             return true;
         }
 
+        public IEnumerator<ActionProbability> GetEnumerator()
+        {
+            return new RankingResponseEnumerator(this);
+        }
+
+        IEnumerator IEnumerable.GetEnumerator()
+        {
+            return this.GetEnumerator();
+        }
+
         private class RankingResponseEnumerator : NativeObject<RankingResponseEnumerator>, IEnumerator<ActionProbability>
         {
             [DllImport("rl.net.native.dll")]
@@ -91,12 +101,17 @@ private static New<RankingResponseEnumerator> BindConstructorArguments(RankingRe
             [DllImport("rl.net.native.dll")]
             private static extern void DeleteRankingEnumeratorAdapter(IntPtr rankingEnumeratorAdapter);
 
+            [DllImport("rl.net.native.dll")]
+            private static extern int RankingEnumeratorInit(IntPtr rankingEnumeratorAdapter);
+
             [DllImport("rl.net.native.dll")]
             private static extern int RankingEnumeratorMoveNext(IntPtr rankingEnumeratorAdapter);
 
             [DllImport("rl.net.native.dll")]
             private static extern ActionProbability GetRankingEnumeratorCurrent(IntPtr rankingEnumeratorAdapter);
 
+            private bool initialState = true;
+
             public RankingResponseEnumerator(RankingResponse rankingResponse) : base(BindConstructorArguments(rankingResponse), new Delete<RankingResponseEnumerator>(DeleteRankingEnumeratorAdapter))
             {
             }
@@ -113,9 +128,18 @@ public ActionProbability Current
 
             public bool MoveNext()
             {
-                // The contract of result is to return 1 if true, 0 if false.
-                int result = RankingEnumeratorMoveNext(this.NativeHandle);
+                int result;
+                if (this.initialState)
+                {
+                    this.initialState = false;
+                    result = RankingEnumeratorInit(this.NativeHandle);
+                }
+                else
+                {
+                    result = RankingEnumeratorMoveNext(this.NativeHandle);
+                }
 
+                // The contract of result is to return 1 if true, 0 if false.
                 return result == 1;
             }