No Enumerable.Last() calls

Author: alex-kulakov

Orm/Xtensive.Orm/Orm/EntitySetBase.cs

@@ -949,7 +949,7 @@ private EntitySetTypeState GetEntitySetTypeState()
 
     private static EntitySetTypeState BuildEntitySetTypeState(FieldInfo field, EntitySetBase entitySet)
     {
-      var association = field.Associations.Last();
+      var association = field.Associations[^1];
       var query = association.UnderlyingIndex.GetQuery().Seek(context => context.GetValue(keyParameter));
       var seek = entitySet.Session.Compile(query);
       var ownerDescriptor = association.OwnerType.Key.TupleDescriptor;
@@ -1060,7 +1060,7 @@ protected EntitySetBase(Entity owner, FieldInfo field)
       this.owner = owner;
       Field = field;
       State = new EntitySetState(this);
-      var association = Field.Associations.Last();
+      var association = Field.Associations[^1];
       if (association.AuxiliaryType != null && association.IsMaster) {
         var domain = Session.Domain;
         var itemType = domain.Model.Types[Field.ItemType];

Orm/Xtensive.Orm/Orm/Internals/Prefetch/EntitySetTask.cs

@@ -56,7 +56,7 @@ internal sealed class EntitySetTask : IEquatable<EntitySetTask>
     private static readonly Parameter<int> itemCountLimitParameter = new Parameter<int>("ItemCountLimit");
 
     private static readonly Func<ItemsQueryCacheKey, CompilableProvider> CreateRecordSetLoadingItems = cachingKey => {
-      var association = cachingKey.ReferencingField.Associations.Last();
+      var association = cachingKey.ReferencingField.Associations[^1];
       var primaryTargetIndex = association.TargetType.Indexes.PrimaryIndex;
       var resultColumns = new List<int>(primaryTargetIndex.Columns.Count);
       var result = association.AuxiliaryType == null
@@ -104,7 +104,7 @@ public void UpdateCache()
       var reader = manager.Owner.Session.Domain.EntityDataReader;
       var records = reader.Read(itemsQueryTask.Result, QueryProvider.Header, manager.Owner.Session);
       var entityKeys = new List<Key>(itemsQueryTask.Result.Count);
-      var association = ReferencingField.Associations.Last();
+      var association = ReferencingField.Associations[^1];
       var auxEntities = (association.AuxiliaryType != null)
         ? new List<Pair<Key, Tuple>>(itemsQueryTask.Result.Count)
         : null;
@@ -191,7 +191,7 @@ private QueryTask CreateQueryTask()
 
     private static CompilableProvider CreateQueryForAssociationViaAuxType(in ItemsQueryCacheKey cachingKey, IndexInfo primaryTargetIndex, List<int> resultColumns)
     {
-      var association = cachingKey.ReferencingField.Associations.Last();
+      var association = cachingKey.ReferencingField.Associations[^1];
       var associationIndex = association.UnderlyingIndex;
       var joiningColumns = GetJoiningColumnIndexes(primaryTargetIndex, associationIndex,
         association.AuxiliaryType != null);
@@ -213,7 +213,7 @@ private static CompilableProvider CreateQueryForAssociationViaAuxType(in ItemsQu
     private static CompilableProvider CreateQueryForDirectAssociation(in ItemsQueryCacheKey cachingKey, IndexInfo primaryTargetIndex, List<int> resultColumns)
     {
       AddResultColumnIndexes(resultColumns, primaryTargetIndex, 0);
-      var association = cachingKey.ReferencingField.Associations.Last();
+      var association = cachingKey.ReferencingField.Associations[^1];
       var field = association.Reversed.OwnerField;
       var keyColumnTypes = field.Columns.SelectToArray(column => column.ValueType);
       return primaryTargetIndex

Orm/Xtensive.Orm/Orm/Internals/Prefetch/GraphContainer.cs

@@ -141,7 +141,7 @@ private static bool AreAllForeignKeyColumnsLoaded(EntityState state, FieldInfo f
     private void RegisterFetchByKnownForeignKey(PrefetchFieldDescriptor referencingFieldDescriptor,
       EntityState ownerState)
     {
-      var association = referencingFieldDescriptor.Field.Associations.Last();
+      var association = referencingFieldDescriptor.Field.Associations[^1];
       var referencedKeyTuple = association
         .ExtractForeignKey(ownerState.Type, ownerState.Tuple);
       var referencedKeyTupleState = referencedKeyTuple.GetFieldStateMap(TupleFieldState.Null);

Orm/Xtensive.Orm/Orm/Internals/Prefetch/ReferencedEntityContainer.cs

@@ -66,7 +66,7 @@ public void NotifyOwnerAboutKeyWithUnknownType()
 
     private Tuple ExtractForeignKeyTuple(EntityState ownerState)
     {
-      var association = ReferencingField.Associations.Last();
+      var association = ReferencingField.Associations[^1];
       var result = association.ExtractForeignKey(ownerState.Type, ownerState.Tuple);
       var tupleState = result.GetFieldStateMap(TupleFieldState.Null);
       for (int i = 0; i < result.Count; i++) {
@@ -118,7 +118,7 @@ private void FillColumnCollection()
 
     public ReferencedEntityContainer(Key ownerKey, PrefetchFieldDescriptor referencingFieldDescriptor,
       bool isOwnerTypeKnown, PrefetchManager manager)
-      : base(null, referencingFieldDescriptor.Field.Associations.Last().TargetType, true, manager)
+      : base(null, referencingFieldDescriptor.Field.Associations[^1].TargetType, true, manager)
     {
       ArgumentValidator.EnsureArgumentNotNull(referencingFieldDescriptor, "referencingFieldDescriptor");
       ArgumentValidator.EnsureArgumentNotNull(ownerKey, "ownerKey");

Orm/Xtensive.Orm/Orm/Linq/QueryHelper.cs

@@ -115,7 +115,7 @@ public static Expression CreateEntitySetQuery(Expression ownerEntity, FieldInfo
       }
 
       var elementType = field.ItemType;
-      var association = field.Associations.Last();
+      var association = field.Associations[^1];
       if (association.Multiplicity==Multiplicity.OneToMany) {
         var targetField = association.TargetType.Fields[association.Reversed.OwnerField.Name];
         var whereParameter = Expression.Parameter(elementType, "p");

Orm/Xtensive.Orm/Orm/Operations/KeyGenerateOperation.cs

@@ -66,7 +66,7 @@ private void MapCompositeKey(OperationExecutionContext context)
           columnIndex++;
         }
         else {
-          var association = keyField.Associations.Last();
+          var association = keyField.Associations[^1];
           var componentKeyValue = Tuple.Create(association.TargetType.Key.TupleDescriptor);
           sourceTuple.CopyTo(componentKeyValue, columnIndex, keyField.MappingInfo.Length);
           var componentKey = Key.Create(domain, nodeId, association.TargetType.UnderlyingType,

Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.Paging.cs

@@ -131,7 +131,7 @@ private SqlProvider VisitPagingRowNumber(PagingProvider provider)
       var source = compiledSource.Request.Statement;
       var queryRef = SqlDml.QueryRef(source);
       var query = SqlDml.Select(queryRef);
-      var rowNumberColumn = queryRef.Columns.Last();
+      var rowNumberColumn = queryRef.Columns[^1];
       query.Columns.AddRange(queryRef.Columns);
       query.Where = SqlDml.Between(rowNumberColumn,
         fromParameterBinding.ParameterReference,

Orm/Xtensive.Orm/Orm/Providers/SqlCompiler.cs

@@ -528,7 +528,7 @@ protected override SqlProvider VisitRowNumber(RowNumberProvider provider)
 
       var query = ExtractSqlSelect(provider, source);
       var rowNumber = SqlDml.RowNumber();
-      query.Columns.Add(rowNumber, header.Columns.Last().Name);
+      query.Columns.Add(rowNumber, header.Columns[^1].Name);
       var columns = ExtractColumnExpressions(query);
       foreach (var order in directionCollection)
         rowNumber.OrderBy.Add(columns[order.Key], order.Value==Direction.Positive);

Orm/Xtensive.Orm/Orm/Rse/Transformation/ColumnMappingInspector.cs

@@ -44,7 +44,7 @@ protected override Provider VisitInclude(IncludeProvider provider)
       var source = VisitCompilable(provider.Source);
 
       var currentMapping = mappings[provider.Source];
-      var calulatedColumn = provider.Header.Columns.Last();
+      var calulatedColumn = provider.Header.Columns[^1];
       mappings[provider] = Merge(currentMapping, EnumerableUtils.One(calulatedColumn.Index));
       if (source == provider.Source) {
         return provider;
@@ -326,7 +326,7 @@ protected override Provider VisitRowNumber(RowNumberProvider provider)
       mappings[provider.Source] = mappings[provider].Where(i => i < sourceLength).ToList();
       var newSource = VisitCompilable(provider.Source);
       var currentMapping = mappings[provider.Source];
-      var rowNumberColumn = provider.Header.Columns.Last();
+      var rowNumberColumn = provider.Header.Columns[^1];
       mappings[provider] = Merge(currentMapping, EnumerableUtils.One(rowNumberColumn.Index));
       return newSource == provider.Source
         ? provider