Make ByDocBlock/DocBlockGroupingSearch non-generic to match Java's wildcard generic erasure for null

Author: paulirwin

src/Lucene.Net.Grouping/GroupingSearch.cs

@@ -56,7 +56,7 @@ namespace Lucene.Net.Search.Grouping
     ///     </item>
     ///     <item>
     ///         <description>
-    ///             <see cref="ByDocBlock{TGroupValue}(Filter)"/> - Constructs a <see cref="DocBlockGroupingSearch{TGroupValue}"/> instance
+    ///             <see cref="ByDocBlock(Filter)"/> - Constructs a <see cref="DocBlockGroupingSearch"/> instance
     ///             that groups documents by doc block. This method can only be used when documents belonging in a group are indexed in one block.
     ///         </description>
     ///     </item>
@@ -72,7 +72,7 @@ namespace Lucene.Net.Search.Grouping
     /// </summary>
     /// <seealso cref="FieldGroupingSearch"/>
     /// <seealso cref="FunctionGroupingSearch{TMutableValue}"/>
-    /// <seealso cref="DocBlockGroupingSearch{TGroupValue}"/>
+    /// <seealso cref="DocBlockGroupingSearch"/>
     public static class GroupingSearch
     {
         /// <summary>
@@ -100,15 +100,14 @@ public static FunctionGroupingSearch<TMutableValue> ByFunction<TMutableValue>(Va
         }
 
         /// <summary>
-        /// Constructs a <see cref="DocBlockGroupingSearch{TGroupValue}"/> instance that groups documents by doc block.
+        /// Constructs a <see cref="DocBlockGroupingSearch"/> instance that groups documents by doc block.
         /// This method can only be used when documents belonging in a group are indexed in one block.
         /// </summary>
         /// <param name="groupEndDocs">The filter that marks the last document in all doc blocks</param>
-        /// <typeparam name="TGroupValue">The type of the group value</typeparam>
-        /// <returns>A <see cref="DocBlockGroupingSearch{TGroupValue}"/> instance.</returns>
-        public static DocBlockGroupingSearch<TGroupValue> ByDocBlock<TGroupValue>(Filter groupEndDocs)
+        /// <returns>A <see cref="DocBlockGroupingSearch"/> instance.</returns>
+        public static DocBlockGroupingSearch ByDocBlock(Filter groupEndDocs)
         {
-            return new DocBlockGroupingSearch<TGroupValue>(groupEndDocs);
+            return new DocBlockGroupingSearch(groupEndDocs);
         }
     }
 
@@ -413,17 +412,17 @@ public override TopGroups<T> Search(IndexSearcher searcher, Filter filter, Query
         }
     }
 
+#nullable enable
     /// <summary>
     /// A grouping search that groups documents by doc block.
     /// This class can only be used when documents belonging in a group are indexed in one block.
     /// </summary>
-    /// <typeparam name="T">The type of the group value</typeparam>
-    public class DocBlockGroupingSearch<T> : AbstractGroupingSearch<T, DocBlockGroupingSearch<T>>
+    public class DocBlockGroupingSearch : AbstractGroupingSearch<object?, DocBlockGroupingSearch>
     {
         private readonly Filter groupEndDocs;
 
         /// <summary>
-        /// Constructs a <see cref="DocBlockGroupingSearch{T}"/> instance that groups documents by doc block.
+        /// Constructs a <see cref="DocBlockGroupingSearch"/> instance that groups documents by doc block.
         /// This class can only be used when documents belonging in a group are indexed in one block.
         /// </summary>
         /// <param name="groupEndDocs">The filter that marks the last document in all doc blocks</param>
@@ -433,14 +432,15 @@ public DocBlockGroupingSearch(Filter groupEndDocs)
         }
 
         /// <inheritdoc cref="AbstractGroupingSearch{T, TSelf}.Search(IndexSearcher,Filter,Query,int,int)"/>
-        public override TopGroups<T> Search(IndexSearcher searcher, Filter filter, Query query, int groupOffset, int groupLimit)
+        public override TopGroups<object?> Search(IndexSearcher searcher, Filter filter, Query query, int groupOffset, int groupLimit)
         {
             int topN = groupOffset + groupLimit;
             BlockGroupingCollector c = new BlockGroupingCollector(GroupSort, topN, IncludeScores, groupEndDocs);
             searcher.Search(query, filter, c);
             int topNInsideGroup = GroupDocsOffset + GroupDocsLimit;
-            return c.GetTopGroups<T>(SortWithinGroup, groupOffset, GroupDocsOffset, topNInsideGroup, FillSortFields);
+            return c.GetTopGroups<object?>(SortWithinGroup, groupOffset, GroupDocsOffset, topNInsideGroup, FillSortFields);
         }
+#nullable restore
     }
 
     /// <summary>

src/Lucene.Net.Grouping/package.md

@@ -140,11 +140,11 @@ Or alternatively use the `GroupingSearch` convenience utility:
 
 ```cs
 // Per search:
-DocBlockGroupingSearch<object> groupingSearch = GroupingSearch.ByDocBlock<object>(groupEndDocs);
+DocBlockGroupingSearch groupingSearch = GroupingSearch.ByDocBlock(groupEndDocs);
 groupingSearch.SetGroupSort(groupSort);
 groupingSearch.SetIncludeScores(needsScores);
 TermQuery query = new TermQuery(new Term("content", searchTerm));
-TopGroups<object> groupsResult = groupingSearch.Search(indexSearcher, query, groupOffset, groupLimit);
+TopGroups<object?> groupsResult = groupingSearch.Search(indexSearcher, query, groupOffset, groupLimit);
 
 // Render groupsResult...
 ```
@@ -166,4 +166,4 @@ int maxDoc = s.MaxDoc;
 FixedBitSet groupHeadsBitSet = c.RetrieveGroupHeads(maxDoc);
 ```
 
-For each of the above collector types there is also a variant that works with `ValueSource` instead of of fields. Concretely this means that these variants can work with functions. These variants are slower than there term based counter parts. These implementations are located in the `Lucene.Net.Search.Grouping.Function` package, but can also be used with the `GroupingSearch` convenience utility
+For each of the above collector types there is also a variant that works with `ValueSource` instead of of fields. Concretely this means that these variants can work with functions. These variants are slower than there term based counter parts. These implementations are located in the `Lucene.Net.Search.Grouping.Function` package, but can also be used with the `GroupingSearch` convenience utility

src/Lucene.Net.Tests.Grouping/GroupingSearchDocExampleTest.cs

@@ -7,6 +7,8 @@
 using NUnit.Framework;
 using System.Collections.Generic;
 
+#nullable enable
+
 namespace Lucene.Net.Search.Grouping
 {
     /*
@@ -70,12 +72,12 @@ public void TestFieldGroupingSearchDocExample()
 
             // --- Code from package.md documentation ---
             Sort groupSort = Sort.RELEVANCE;
-            bool fillFields = true;
-            bool useCache = true;
-            bool requiredTotalGroupCount = true;
-            string searchTerm = "random";
-            int groupOffset = 0;
-            int groupLimit = 10;
+            const bool fillFields = true;
+            const bool useCache = true;
+            const bool requiredTotalGroupCount = true;
+            const string searchTerm = "random";
+            const int groupOffset = 0;
+            const int groupLimit = 10;
 
             FieldGroupingSearch groupingSearch = GroupingSearch.ByField("author");
             groupingSearch.SetGroupSort(groupSort);
@@ -104,7 +106,7 @@ public void TestFieldGroupingSearchDocExample()
             {
                 int? totalGroupCount = result.TotalGroupCount;
                 Assert.IsNotNull(totalGroupCount);
-                assertEquals(2, totalGroupCount.Value);
+                assertEquals(2, totalGroupCount!.Value);
             }
 
             indexSearcher.IndexReader.Dispose();
@@ -113,7 +115,7 @@ public void TestFieldGroupingSearchDocExample()
 
         /// <summary>
         /// Tests the "GroupingSearch convenience utility" example for doc block grouping
-        /// from the package.md documentation using <see cref="GroupingSearch.ByDocBlock{TGroupValue}(Filter)"/>.
+        /// from the package.md documentation using <see cref="GroupingSearch.ByDocBlock(Filter)"/>.
         /// </summary>
         [Test]
         public void TestDocBlockGroupingSearchDocExample()
@@ -155,20 +157,20 @@ public void TestDocBlockGroupingSearchDocExample()
 
             // --- Search code from package.md documentation ---
             Sort groupSort = Sort.RELEVANCE;
-            bool needsScores = true;
-            string searchTerm = "random";
-            int groupOffset = 0;
-            int groupLimit = 10;
+            const bool needsScores = true;
+            const string searchTerm = "random";
+            const int groupOffset = 0;
+            const int groupLimit = 10;
 
             // Set this once in your app & save away for reusing across all queries:
             Filter groupEndDocs = new CachingWrapperFilter(new QueryWrapperFilter(new TermQuery(new Index.Term("groupEnd", "x"))));
 
             // Per search:
-            DocBlockGroupingSearch<object> groupingSearch = GroupingSearch.ByDocBlock<object>(groupEndDocs);
+            DocBlockGroupingSearch groupingSearch = GroupingSearch.ByDocBlock(groupEndDocs);
             groupingSearch.SetGroupSort(groupSort);
             groupingSearch.SetIncludeScores(needsScores);
             TermQuery query = new TermQuery(new Index.Term("content", searchTerm));
-            TopGroups<object> groupsResult = groupingSearch.Search(indexSearcher, query, groupOffset, groupLimit);
+            TopGroups<object?> groupsResult = groupingSearch.Search(indexSearcher, query, groupOffset, groupLimit);
 
             // Verify results
             Assert.IsNotNull(groupsResult);

src/Lucene.Net.Tests.Grouping/GroupingSearchFluentApiTest.cs

@@ -203,26 +203,26 @@ public void TestFunctionGroupingSearch_FullChaining()
         [Test]
         public void TestDocBlockGroupingSearch_SetGroupSort_ReturnsConcrete()
         {
-            DocBlockGroupingSearch<object> result = GroupingSearch
-                .ByDocBlock<object>(null)
+            DocBlockGroupingSearch result = GroupingSearch
+                .ByDocBlock(null)
                 .SetGroupSort(Sort.RELEVANCE);
             Assert.IsNotNull(result);
         }
 
         [Test]
         public void TestDocBlockGroupingSearch_SetIncludeScores_ReturnsConcrete()
         {
-            DocBlockGroupingSearch<object> result = GroupingSearch
-                .ByDocBlock<object>(null)
+            DocBlockGroupingSearch result = GroupingSearch
+                .ByDocBlock(null)
                 .SetIncludeScores(true);
             Assert.IsNotNull(result);
         }
 
         [Test]
         public void TestDocBlockGroupingSearch_FullChaining()
         {
-            DocBlockGroupingSearch<object> result = GroupingSearch
-                .ByDocBlock<object>(null)
+            DocBlockGroupingSearch result = GroupingSearch
+                .ByDocBlock(null)
                 .SetGroupSort(Sort.RELEVANCE)
                 .SetSortWithinGroup(Sort.RELEVANCE)
                 .SetGroupDocsOffset(0)

src/Lucene.Net.Tests.Grouping/GroupingSearchTest.cs

@@ -156,7 +156,7 @@ public virtual void TestBasic()
             // LUCENENET: using SearchDelegate callback to encapsulate non-covariant generic type use
             groupingSearch = (searcher, filter, query, offset, limit) =>
             {
-                var topGroups = GroupingSearch.ByDocBlock<object>(lastDocInBlock).Search(searcher, filter, query, offset, limit);
+                var topGroups = GroupingSearch.ByDocBlock(lastDocInBlock).Search(searcher, filter, query, offset, limit);
 
                 return new GroupingSearchResult
                 {