TopologicalSorter:Added annotations to return types

Author: alex-kulakov

Orm/Xtensive.Orm/Sorting/TopologicalSorter.cs

@@ -9,7 +9,9 @@
 using Xtensive.Collections;
 using System.Linq;
 using Xtensive.Core;
-
+using DotNetNotNullAttribute = System.Diagnostics.CodeAnalysis.NotNullAttribute;
+using JBNotNullAttribute = JetBrains.Annotations.NotNullAttribute;
+using JBCanBeNullAttribute = JetBrains.Annotations.CanBeNullAttribute;
 
 namespace Xtensive.Sorting
 {
@@ -29,6 +31,7 @@ public static class TopologicalSorter
     /// Sorting result, if there were no loops;
     /// otherwise, <see langword="null"/>.
     /// </returns>
+    [JBCanBeNull]
     public static IEnumerable<TNodeItem> Sort<TNodeItem>(IEnumerable<TNodeItem> items, Predicate<TNodeItem, TNodeItem> connector) =>
       Sort(items, connector, out List<Node<TNodeItem, object>> loops);
 
@@ -43,6 +46,7 @@ public static IEnumerable<TNodeItem> Sort<TNodeItem>(IEnumerable<TNodeItem> item
     /// Sorting result, if there were no loops;
     /// otherwise, <see langword="null"/>.
     /// </returns>
+    [JBCanBeNull]
     public static IReadOnlyList<TNodeItem> SortToList<TNodeItem>(IEnumerable<TNodeItem> items, Predicate<TNodeItem, TNodeItem> connector) =>
       SortToList(items, connector, out List<Node<TNodeItem, object>> loops);
 
@@ -59,6 +63,7 @@ public static IReadOnlyList<TNodeItem> SortToList<TNodeItem>(IEnumerable<TNodeIt
     /// otherwise, <see langword="null"/>.
     /// In this case <paramref name="loops"/> will contain only the loop edges.
     /// </returns>
+    [JBCanBeNull]
     public static IEnumerable<TNodeItem> Sort<TNodeItem>(
       IEnumerable<TNodeItem> items,
       Predicate<TNodeItem, TNodeItem> connector,
@@ -83,6 +88,7 @@ public static IEnumerable<TNodeItem> Sort<TNodeItem>(
     /// otherwise, <see langword="null"/>.
     /// In this case <paramref name="loops"/> will contain only the loop edges.
     /// </returns>
+    [JBCanBeNull]
     public static IReadOnlyList<TNodeItem> SortToList<TNodeItem>(
       IEnumerable<TNodeItem> items,
       Predicate<TNodeItem, TNodeItem> connector,
@@ -105,6 +111,8 @@ public static IReadOnlyList<TNodeItem> SortToList<TNodeItem>(
     /// <returns>
     /// Sorting result
     /// </returns>
+    [return: DotNetNotNull]
+    [JBNotNull]
     public static IEnumerable<TNodeItem> Sort<TNodeItem>(
       IEnumerable<TNodeItem> items,
       Predicate<TNodeItem, TNodeItem> connector,
@@ -121,6 +129,8 @@ public static IEnumerable<TNodeItem> Sort<TNodeItem>(
     /// <returns>
     /// Sorting result
     /// </returns>
+    [return: DotNetNotNull]
+    [JBNotNull]
     public static IReadOnlyList<TNodeItem> SortToList<TNodeItem>(
       IEnumerable<TNodeItem> items,
       Predicate<TNodeItem, TNodeItem> connector,
@@ -138,6 +148,8 @@ public static IReadOnlyList<TNodeItem> SortToList<TNodeItem>(
     /// <returns>
     /// Sorting result
     /// </returns>
+    [return: DotNetNotNull]
+    [JBNotNull]
     public static IEnumerable<TNodeItem> Sort<TNodeItem>(
       IEnumerable<TNodeItem> items,
       Predicate<TNodeItem, TNodeItem> connector,
@@ -161,6 +173,8 @@ public static IEnumerable<TNodeItem> Sort<TNodeItem>(
     /// <returns>
     /// Sorting result
     /// </returns>
+    [return: DotNetNotNull]
+    [JBNotNull]
     public static IReadOnlyList<TNodeItem> SortToList<TNodeItem>(
       IEnumerable<TNodeItem> items,
       Predicate<TNodeItem, TNodeItem> connector,
@@ -181,6 +195,7 @@ public static IReadOnlyList<TNodeItem> SortToList<TNodeItem>(
     /// <returns>Sorting result, if there were no loops;
     /// otherwise, <see langword="null" />. 
     /// In this case <paramref name="nodes"/> will contain only the loop edges.</returns>
+    [JBCanBeNull]
     public static IEnumerable<TNodeItem> Sort<TNodeItem, TConnectionItem>(
       List<Node<TNodeItem, TConnectionItem>> nodes,
       out List<Node<TNodeItem, TConnectionItem>> loops)
@@ -200,6 +215,7 @@ public static IEnumerable<TNodeItem> Sort<TNodeItem, TConnectionItem>(
     /// <returns>Sorting result, if there were no loops;
     /// otherwise, <see langword="null" />. 
     /// In this case <paramref name="nodes"/> will contain only the loop edges.</returns>
+    [JBCanBeNull]
     public static IReadOnlyList<TNodeItem> SortToList<TNodeItem, TConnectionItem>(
       List<Node<TNodeItem, TConnectionItem>> nodes,
       out List<Node<TNodeItem, TConnectionItem>> loops)
@@ -219,6 +235,8 @@ public static IReadOnlyList<TNodeItem> SortToList<TNodeItem, TConnectionItem>(
     /// <param name="nodes">The nodes.</param>
     /// <param name="removedEdges">Edges removed to make graph non-cyclic.</param>
     /// <returns>Sorting result.</returns>
+    [return: DotNetNotNull]
+    [JBNotNull]
     public static IEnumerable<TNodeItem> Sort<TNodeItem, TConnectionItem>(
       IEnumerable<Node<TNodeItem, TConnectionItem>> nodes,
       out List<NodeConnection<TNodeItem, TConnectionItem>> removedEdges) =>
@@ -231,6 +249,8 @@ public static IEnumerable<TNodeItem> Sort<TNodeItem, TConnectionItem>(
     /// <param name="nodes">The nodes.</param>
     /// <param name="removedEdges">Edges removed to make graph non-cyclic.</param>
     /// <returns>Sorting result.</returns>
+    [return: DotNetNotNull]
+    [JBNotNull]
     public static IReadOnlyList<TNodeItem> SortToList<TNodeItem, TConnectionItem>(
       IEnumerable<Node<TNodeItem, TConnectionItem>> nodes,
       out List<NodeConnection<TNodeItem, TConnectionItem>> removedEdges) =>
@@ -244,6 +264,8 @@ public static IReadOnlyList<TNodeItem> SortToList<TNodeItem, TConnectionItem>(
     /// <param name="removedEdges">Edges removed to make graph non-cyclic.</param>
     /// <param name="removeWholeNode">If <see langword="true"/> removes whole node in the case of loop, otherwise removes only one edge.</param>
     /// <returns>Sorting result.</returns>
+    [return: DotNetNotNull]
+    [JBNotNull]
     public static IEnumerable<TNodeItem> Sort<TNodeItem, TConnectionItem>(
         IEnumerable<Node<TNodeItem, TConnectionItem>> nodes,
         out List<NodeConnection<TNodeItem, TConnectionItem>> removedEdges,
@@ -258,6 +280,8 @@ public static IEnumerable<TNodeItem> Sort<TNodeItem, TConnectionItem>(
     /// <param name="removedEdges">Edges removed to make graph non-cyclic.</param>
     /// <param name="removeWholeNode">If <see langword="true"/> removes whole node in the case of loop, otherwise removes only one edge.</param>
     /// <returns>Sorting result.</returns>
+    [return: DotNetNotNull]
+    [JBNotNull]
     public static IReadOnlyList<TNodeItem> SortToList<TNodeItem, TConnectionItem>(
       IEnumerable<Node<TNodeItem, TConnectionItem>> nodes,
       out List<NodeConnection<TNodeItem, TConnectionItem>> removedEdges,