Work in progress.

Author: rstam

src/MongoDB.Driver/Linq/Linq3Implementation/KnownSerializerFinders/KnownSerializerFinder.cs

@@ -60,18 +60,13 @@ public static KnownSerializerMap FindKnownSerializers(
     {
         var visitor = new KnownSerializerFinderVisitor(translationOptions, knownSerializers);
 
-        int oldSerializerCount;
-        int newSerializerCount;
         do
         {
-            visitor.StartNextPass();
-            oldSerializerCount = knownSerializers.Count;
+            visitor.StartPass();
             visitor.Visit(expression);
-            newSerializerCount = knownSerializers.Count;
-
-            // TODO: prevent infinite loop, throw after 100000 passes?
+            visitor.EndPass();
         }
-        while (visitor.Pass == 1 || newSerializerCount > oldSerializerCount); // I don't know yet if this can be done in a single pass
+        while (visitor.IsMakingProgress);
 
         //#if DEBUG
         var expressionWithUnknownSerializer = UnknownSerializerFinder.FindExpressionWithUnknownSerializer(expression, knownSerializers);

src/MongoDB.Driver/Linq/Linq3Implementation/KnownSerializerFinders/KnownSerializerFinderVisitConditional.cs

@@ -30,7 +30,6 @@ protected override Expression VisitConditional(ConditionalExpression node)
         base.VisitConditional(node);
 
         DeduceSerializers(ifTrue, ifFalse);
-        DeduceSerializers(ifFalse, ifTrue);
         DeduceSerializers(node, ifTrue);
 
         return node;

src/MongoDB.Driver/Linq/Linq3Implementation/KnownSerializerFinders/KnownSerializerFinderVisitConstant.cs

@@ -23,27 +23,17 @@ internal partial class KnownSerializerFinderVisitor
 {
     protected override Expression VisitConstant(ConstantExpression node)
     {
-        if (IsNotKnown(node))
+        if (IsNotKnown(node) && _useDefaultSerializerForConstants)
         {
-            var value = node.Value;
-            IBsonSerializer constantSerializer = null;
-
-            if (_pass > 1)
+            if (StandardSerializers.TryGetSerializer(node.Type, out var standardSerializer))
             {
-                if (StandardSerializers.TryGetSerializer(node.Type, out constantSerializer))
-                {
-                    // constant => node: standardSerializer
-                }
-                else
-                {
-                    // constant => node: registeredSerializer
-                    constantSerializer = BsonSerializer.LookupSerializer(node.Type); // TODO: don't use static registry
-                }
+                AddKnownSerializer(node, standardSerializer);
             }
-
-            if (constantSerializer != null)
+            else
             {
-                AddKnownSerializer(node, constantSerializer);
+                // constant => node: registeredSerializer
+                var registeredSerializer = BsonSerializer.LookupSerializer(node.Type); // TODO: don't use static registry
+                AddKnownSerializer(node, registeredSerializer);
             }
         }
 

src/MongoDB.Driver/Linq/Linq3Implementation/KnownSerializerFinders/KnownSerializerFinderVisitIndex.cs

@@ -27,49 +27,39 @@ protected override Expression VisitIndex(IndexExpression node)
     {
         base.VisitIndex(node);
 
-        var containerExpression = node.Object;
+        var collectionExpression = node.Object;
         var indexer = node.Indexer;
         var arguments = node.Arguments;
 
         if (IsBsonValueIndexer())
         {
-            var keyExpression = arguments[0];
-
-            DeduceSerializer(keyExpression, keyExpression.Type == typeof(string) ? StringSerializer.Instance : Int32Serializer.Instance);
             DeduceSerializer(node, BsonValueSerializer.Instance);
         }
         else if (IsDictionaryIndexer())
         {
-            var keyExpression = arguments[0];
-
-            if (IsKnown(containerExpression, out var containerSerializer) &&
-                containerSerializer is IBsonDictionarySerializer dictionarySerializer)
+            if (IsKnown(collectionExpression, out var collectionSerializer) &&
+                collectionSerializer is IBsonDictionarySerializer dictionarySerializer)
             {
-                var keySerializer = dictionarySerializer.KeySerializer;
                 var valueSerializer = dictionarySerializer.ValueSerializer;
-
-                DeduceSerializer(keyExpression, keySerializer);
                 DeduceSerializer(node, valueSerializer);
             }
         }
         // check array indexer AFTER dictionary indexer
-        else if (IsArrayIndexer())
+        else if (IsCollectionIndexer())
         {
-            var indexExpression = arguments[0];
-
-            if (IsKnown(containerExpression, out var containerSerializer) &&
-                containerSerializer is IBsonArraySerializer arraySerializer)
+            if (IsKnown(collectionExpression, out var collectionSerializer) &&
+                collectionSerializer is IBsonArraySerializer arraySerializer)
             {
                 var itemSerializer = arraySerializer.GetItemSerializer();
-
-                DeduceSerializer(indexExpression, Int32Serializer.Instance);
                 DeduceSerializer(node, itemSerializer);
             }
         }
+        // TODO: Deduce UnknowableSerializer???
+        // handle generic cases?
 
         return node;
 
-        bool IsArrayIndexer()
+        bool IsCollectionIndexer()
         {
             return
                 arguments.Count == 1 &&

src/MongoDB.Driver/Linq/Linq3Implementation/KnownSerializerFinders/KnownSerializerFinderVisitMember.cs

@@ -101,6 +101,7 @@ IBsonSerializer GetBsonValuePropertySerializer()
                 "AsRegex" => RegexSerializer.RegularExpressionInstance,
                 "AsString" => StringSerializer.Instance,
                 "AsUniversalTime" => DateTimeSerializer.UtcInstance,
+                // TODO: return UnknowableSerializer???
                 _ => throw new ExpressionNotSupportedException(node, because: $"Unexpected member name: {memberName}")
             };
         }
@@ -129,6 +130,7 @@ IBsonSerializer GetDateTimePropertySerializer()
                 "Today" => DateTimeSerializer.Instance,
                 "UtcNow" => DateTimeSerializer.Instance,
                 "Year" => Int32Serializer.Instance,
+                // TODO: return UnknowableSerializer???
                 _ => throw new ExpressionNotSupportedException(node, because: $"Unexpected member name: {memberName}")
             };
         }
@@ -139,6 +141,7 @@ IBsonSerializer GetNullablePropertySerializer()
             {
                 "HasValue" => BooleanSerializer.Instance,
                 "Value" => (containingSerializer as INullableSerializer)?.ValueSerializer,
+                // TODO: return UnknowableSerializer???
                 _ => throw new ExpressionNotSupportedException(node, because: $"Unexpected member name: {memberName}")
             };
         }
@@ -147,13 +150,16 @@ IBsonSerializer GetPropertySerializer()
         {
             if (containingSerializer is not IBsonDocumentSerializer documentSerializer)
             {
+                // TODO: return UnknowableSerializer???
                 throw new ExpressionNotSupportedException(node, because: $"serializer type {containingSerializer.GetType()} does not implement the {nameof(IBsonDocumentSerializer)} interface");
             }
 
             if (!documentSerializer.TryGetMemberSerializationInfo(memberName, out var memberSerializationInfo))
             {
+                // TODO: return UnknowableSerializer???
                 throw new ExpressionNotSupportedException(node, because: $"serializer type {containingSerializer.GetType()} does not support a member named: {memberName}");
             }
+
             return memberSerializationInfo.Serializer;
         }
 
@@ -174,6 +180,7 @@ IBsonSerializer GetTupleOrValueTuplePropertySerializer()
                 "Item6" => tupleSerializer.GetItemSerializer(6),
                 "Item7" => tupleSerializer.GetItemSerializer(7),
                 "Rest" => tupleSerializer.GetItemSerializer(8),
+                // TODO: return UnknowableSerializer???
                 _ => throw new ExpressionNotSupportedException(node, because: $"Unexpected member name: {memberName}")
             };
         }