From 6ac702613fb5d8d4b1a086e43fb42108ec5b3903 Mon Sep 17 00:00:00 2001
From: "Darrin W. Cullop" <Darrin.Cullop@microsoft.com>
Date: Thu, 9 Nov 2023 00:17:26 -0800
Subject: [PATCH] ToConcreteType Update (#751)

Convert more places to use ToConcreteType
---
 .../Aggregation/AggregateEnumerator.cs        |  5 +++--
 src/DynamicData/Binding/BindingListAdaptor.cs |  4 ++--
 .../Binding/ObservableCollectionAdaptor.cs    | 20 ++-----------------
 src/DynamicData/Cache/CacheChangeSetEx.cs     | 13 ++++++++----
 .../Cache/Internal/AbstractFilter.cs          |  4 ++--
 src/DynamicData/Cache/Internal/Cache.cs       |  2 +-
 src/DynamicData/Cache/Internal/Cast.cs        |  2 +-
 src/DynamicData/Cache/Internal/Combiner.cs    |  2 +-
 src/DynamicData/Cache/Internal/DisposeMany.cs |  2 +-
 .../Cache/Internal/IndexCalculator.cs         |  2 +-
 .../Cache/Internal/RemoveKeyEnumerator.cs     |  2 +-
 .../Cache/Internal/TransformMany.cs           |  2 +-
 src/DynamicData/Cache/ObservableCacheEx.cs    |  5 +++--
 src/DynamicData/Platforms/net45/PFilter.cs    |  2 +-
 14 files changed, 29 insertions(+), 38 deletions(-)

diff --git a/src/DynamicData/Aggregation/AggregateEnumerator.cs b/src/DynamicData/Aggregation/AggregateEnumerator.cs
index 27ad8e625..7800f3346 100644
--- a/src/DynamicData/Aggregation/AggregateEnumerator.cs
+++ b/src/DynamicData/Aggregation/AggregateEnumerator.cs
@@ -5,6 +5,7 @@
 using System.Collections;
 using System.Collections.Generic;
 using System.Diagnostics.CodeAnalysis;
+using DynamicData.Cache;
 
 namespace DynamicData.Aggregation;
 
@@ -68,11 +69,11 @@ internal class AggregateEnumerator<TObject, TKey> : IAggregateChangeSet<TObject>
     where TObject : notnull
     where TKey : notnull
 {
-    private readonly IChangeSet<TObject, TKey> _source;
+    private readonly ChangeSet<TObject, TKey> _source;
 
     public AggregateEnumerator(IChangeSet<TObject, TKey> source)
     {
-        _source = source;
+        _source = source.ToConcreteType();
     }
 
     public IEnumerator<AggregateItem<TObject>> GetEnumerator()
diff --git a/src/DynamicData/Binding/BindingListAdaptor.cs b/src/DynamicData/Binding/BindingListAdaptor.cs
index 5ca39454e..d11944e7b 100644
--- a/src/DynamicData/Binding/BindingListAdaptor.cs
+++ b/src/DynamicData/Binding/BindingListAdaptor.cs
@@ -5,7 +5,7 @@
 #if SUPPORTS_BINDINGLIST
 using System.ComponentModel;
 using System.Diagnostics.CodeAnalysis;
-
+using DynamicData.Cache;
 using DynamicData.Cache.Internal;
 
 namespace DynamicData.Binding
@@ -108,7 +108,7 @@ public void Adapt(IChangeSet<TObject, TKey> changes)
 
         private static void DoUpdate(IChangeSet<TObject, TKey> changes, BindingList<TObject> list)
         {
-            foreach (var update in changes)
+            foreach (var update in changes.ToConcreteType())
             {
                 switch (update.Reason)
                 {
diff --git a/src/DynamicData/Binding/ObservableCollectionAdaptor.cs b/src/DynamicData/Binding/ObservableCollectionAdaptor.cs
index a373be9aa..6926fa702 100644
--- a/src/DynamicData/Binding/ObservableCollectionAdaptor.cs
+++ b/src/DynamicData/Binding/ObservableCollectionAdaptor.cs
@@ -4,7 +4,7 @@
 
 using System;
 using System.Diagnostics.CodeAnalysis;
-
+using DynamicData.Cache;
 using DynamicData.Cache.Internal;
 using DynamicData.Kernel;
 
@@ -128,7 +128,7 @@ public void Adapt(IChangeSet<TObject, TKey> changes, IObservableCollection<TObje
 
     private void DoUpdate(IChangeSet<TObject, TKey> changes, IObservableCollection<TObject> list)
     {
-        void Amend(Change<TObject, TKey> change)
+        foreach (Change<TObject, TKey> change in changes.ToConcreteType())
         {
             switch (change.Reason)
             {
@@ -156,21 +156,5 @@ void Amend(Change<TObject, TKey> change)
                     break;
             }
         }
-
-        if (changes is IList<Change<TObject, TKey>> iList)
-        {
-            // allocation free enumeration
-            foreach (var change in EnumerableIList.Create(iList))
-            {
-                Amend(change);
-            }
-        }
-        else
-        {
-            foreach (var update in changes)
-            {
-                Amend(update);
-            }
-        }
     }
 }
diff --git a/src/DynamicData/Cache/CacheChangeSetEx.cs b/src/DynamicData/Cache/CacheChangeSetEx.cs
index 7ab076a0b..edbc8a825 100644
--- a/src/DynamicData/Cache/CacheChangeSetEx.cs
+++ b/src/DynamicData/Cache/CacheChangeSetEx.cs
@@ -9,14 +9,19 @@ internal static class CacheChangeSetEx
     /// <summary>
     /// IChangeSet is flawed because it automatically means allocations when enumerating.
     /// This extension is a crazy hack to cast to the concrete change set which means we no longer allocate
-    /// as  change set now inherits from List which has allocation free enumerations.
+    /// as change set now inherits from List which has allocation free enumerations.
     ///
-    /// IChangeSet will be removed in V7 and instead Change sets will be used directly
+    /// IChangeSet will be removed in a future version and instead <see cref="ChangeSet{TObject, TKey}"/> will be used directly.
     ///
     /// In the mean time I am banking that no-one has implemented a custom change set - personally I think it is very unlikely.
     /// </summary>
-    /// <param name="changeSet">The source change set.</param>
+    /// <typeparam name="TObject">ChangeSet Object Type.</typeparam>
+    /// <typeparam name="TKey">ChangeSet Key Type.</typeparam>
+    /// <param name="changeSet">ChangeSet to be converted.</param>
+    /// <returns>Concrete Instance of the ChangeSet.</returns>
+    /// <exception cref="NotSupportedException">A custom implementation was found.</exception>
     public static ChangeSet<TObject, TKey> ToConcreteType<TObject, TKey>(this IChangeSet<TObject, TKey> changeSet)
         where TObject : notnull
-        where TKey : notnull => (ChangeSet<TObject, TKey>)changeSet;
+        where TKey : notnull =>
+            changeSet as ChangeSet<TObject, TKey> ?? throw new NotSupportedException("Dynamic Data does not support a custom implementation of IChangeSet");
 }
diff --git a/src/DynamicData/Cache/Internal/AbstractFilter.cs b/src/DynamicData/Cache/Internal/AbstractFilter.cs
index d76dabeff..34db2d95a 100644
--- a/src/DynamicData/Cache/Internal/AbstractFilter.cs
+++ b/src/DynamicData/Cache/Internal/AbstractFilter.cs
@@ -59,11 +59,11 @@ Optional<Change<TObject, TKey>> Factory(KeyValuePair<TKey, TObject> kv)
 
     public IChangeSet<TObject, TKey> Update(IChangeSet<TObject, TKey> updates)
     {
-        var withFilter = GetChangesWithFilter(updates);
+        var withFilter = GetChangesWithFilter(updates.ToConcreteType());
         return ProcessResult(withFilter);
     }
 
-    protected abstract IEnumerable<UpdateWithFilter> GetChangesWithFilter(IChangeSet<TObject, TKey> updates);
+    protected abstract IEnumerable<UpdateWithFilter> GetChangesWithFilter(ChangeSet<TObject, TKey> updates);
 
     protected abstract IEnumerable<Change<TObject, TKey>> Refresh(IEnumerable<KeyValuePair<TKey, TObject>> items, Func<KeyValuePair<TKey, TObject>, Optional<Change<TObject, TKey>>> factory);
 
diff --git a/src/DynamicData/Cache/Internal/Cache.cs b/src/DynamicData/Cache/Internal/Cache.cs
index d1477c793..623b28e75 100644
--- a/src/DynamicData/Cache/Internal/Cache.cs
+++ b/src/DynamicData/Cache/Internal/Cache.cs
@@ -47,7 +47,7 @@ public void Clone(IChangeSet<TObject, TKey> changes)
             throw new ArgumentNullException(nameof(changes));
         }
 
-        foreach (var item in changes)
+        foreach (var item in changes.ToConcreteType())
         {
             switch (item.Reason)
             {
diff --git a/src/DynamicData/Cache/Internal/Cast.cs b/src/DynamicData/Cache/Internal/Cast.cs
index f006a0eba..051be77f1 100644
--- a/src/DynamicData/Cache/Internal/Cast.cs
+++ b/src/DynamicData/Cache/Internal/Cast.cs
@@ -30,7 +30,7 @@ public IObservable<IChangeSet<TDestination, TKey>> Run()
         return _source.Select(
             changes =>
             {
-                var transformed = changes.Select(change => new Change<TDestination, TKey>(change.Reason, change.Key, _converter(change.Current), change.Previous.Convert(_converter), change.CurrentIndex, change.PreviousIndex));
+                var transformed = changes.ToConcreteType().Select(change => new Change<TDestination, TKey>(change.Reason, change.Key, _converter(change.Current), change.Previous.Convert(_converter), change.CurrentIndex, change.PreviousIndex));
                 return new ChangeSet<TDestination, TKey>(transformed);
             });
     }
diff --git a/src/DynamicData/Cache/Internal/Combiner.cs b/src/DynamicData/Cache/Internal/Combiner.cs
index 758868282..5b9e0d648 100644
--- a/src/DynamicData/Cache/Internal/Combiner.cs
+++ b/src/DynamicData/Cache/Internal/Combiner.cs
@@ -106,7 +106,7 @@ private void Update(Cache<TObject, TKey> cache, IChangeSet<TObject, TKey> update
     private IChangeSet<TObject, TKey> UpdateCombined(IChangeSet<TObject, TKey> updates)
     {
         // child caches have been updated before we reached this point.
-        foreach (var update in updates)
+        foreach (var update in updates.ToConcreteType())
         {
             TKey key = update.Key;
             switch (update.Reason)
diff --git a/src/DynamicData/Cache/Internal/DisposeMany.cs b/src/DynamicData/Cache/Internal/DisposeMany.cs
index 41b6e061e..2b0091c58 100644
--- a/src/DynamicData/Cache/Internal/DisposeMany.cs
+++ b/src/DynamicData/Cache/Internal/DisposeMany.cs
@@ -49,7 +49,7 @@ public IObservable<IChangeSet<TObject, TKey>> Run()
 
     private void RegisterForRemoval(IChangeSet<TObject, TKey> changes, Cache<TObject, TKey> cache)
     {
-        changes.ForEach(
+        changes.ToConcreteType().ForEach(
             change =>
             {
                 switch (change.Reason)
diff --git a/src/DynamicData/Cache/Internal/IndexCalculator.cs b/src/DynamicData/Cache/Internal/IndexCalculator.cs
index 57bbfcb50..ad42bbdd1 100644
--- a/src/DynamicData/Cache/Internal/IndexCalculator.cs
+++ b/src/DynamicData/Cache/Internal/IndexCalculator.cs
@@ -47,7 +47,7 @@ public IChangeSet<TObject, TKey> Calculate(IChangeSet<TObject, TKey> changes)
         var result = new List<Change<TObject, TKey>>(changes.Count);
         var refreshes = new List<Change<TObject, TKey>>(changes.Refreshes);
 
-        foreach (var u in changes)
+        foreach (var u in changes.ToConcreteType())
         {
             var current = new KeyValuePair<TKey, TObject>(u.Key, u.Current);
 
diff --git a/src/DynamicData/Cache/Internal/RemoveKeyEnumerator.cs b/src/DynamicData/Cache/Internal/RemoveKeyEnumerator.cs
index 554cd1aaa..19676413d 100644
--- a/src/DynamicData/Cache/Internal/RemoveKeyEnumerator.cs
+++ b/src/DynamicData/Cache/Internal/RemoveKeyEnumerator.cs
@@ -36,7 +36,7 @@ public RemoveKeyEnumerator(IChangeSet<TObject, TKey> source, IExtendedList<TObje
     /// </returns>
     public IEnumerator<Change<TObject>> GetEnumerator()
     {
-        foreach (var change in _source)
+        foreach (var change in _source.ToConcreteType())
         {
             switch (change.Reason)
             {
diff --git a/src/DynamicData/Cache/Internal/TransformMany.cs b/src/DynamicData/Cache/Internal/TransformMany.cs
index fbdcbe042..31cf4e83a 100644
--- a/src/DynamicData/Cache/Internal/TransformMany.cs
+++ b/src/DynamicData/Cache/Internal/TransformMany.cs
@@ -207,7 +207,7 @@ public DestinationEnumerator(IChangeSet<ManyContainer, TSourceKey> changes)
 
         public IEnumerator<Change<TDestination, TDestinationKey>> GetEnumerator()
         {
-            foreach (var change in _changes)
+            foreach (var change in _changes.ToConcreteType())
             {
                 switch (change.Reason)
                 {
diff --git a/src/DynamicData/Cache/ObservableCacheEx.cs b/src/DynamicData/Cache/ObservableCacheEx.cs
index 11cdb311b..368f490f1 100644
--- a/src/DynamicData/Cache/ObservableCacheEx.cs
+++ b/src/DynamicData/Cache/ObservableCacheEx.cs
@@ -14,6 +14,7 @@
 using System.Reactive.Linq;
 
 using DynamicData.Binding;
+using DynamicData.Cache;
 using DynamicData.Cache.Internal;
 using DynamicData.Kernel;
 
@@ -1058,7 +1059,7 @@ public static IObservable<IChangeSet<TObject, TKey>> Clone<TObject, TKey>(this I
         return source.Do(
             changes =>
             {
-                foreach (var item in changes)
+                foreach (var item in changes.ToConcreteType())
                 {
                     switch (item.Reason)
                     {
@@ -6200,7 +6201,7 @@ public static IObservable<ISortedChangeSet<TObject, TKey>> TreatMovesAsRemoveAdd
 
         IEnumerable<Change<TObject, TKey>> ReplaceMoves(IChangeSet<TObject, TKey> items)
         {
-            foreach (var change in items)
+            foreach (var change in items.ToConcreteType())
             {
                 if (change.Reason == ChangeReason.Moved)
                 {
diff --git a/src/DynamicData/Platforms/net45/PFilter.cs b/src/DynamicData/Platforms/net45/PFilter.cs
index c5e2eefc1..b1fec41cf 100644
--- a/src/DynamicData/Platforms/net45/PFilter.cs
+++ b/src/DynamicData/Platforms/net45/PFilter.cs
@@ -51,7 +51,7 @@ public PLinqFilteredUpdater(Func<TObject, bool> filter, ParallelisationOptions p
                 _parallelisationOptions = parallelisationOptions;
             }
 
-            protected override IEnumerable<UpdateWithFilter> GetChangesWithFilter(IChangeSet<TObject, TKey> updates)
+            protected override IEnumerable<UpdateWithFilter> GetChangesWithFilter(ChangeSet<TObject, TKey> updates)
             {
                 if (updates.ShouldParallelise(_parallelisationOptions))
                 {