Return CompilableProvider from Visitors

Author: SergeiPavlov

Orm/Xtensive.Orm/Orm/Rse/Providers/CompilableProviderVisitor.cs

@@ -73,14 +73,12 @@ protected override CompilableProvider VisitSelect(SelectProvider provider)
     }
 
     /// <inheritdoc/>
-    protected override TagProvider VisitTag(TagProvider provider)
+    protected override CompilableProvider VisitTag(TagProvider provider)
     {
       OnRecursionEntrance(provider);
       var source = VisitCompilable(provider.Source);
       OnRecursionExit(provider);
-      if (source == provider.Source)
-        return provider;
-      return new TagProvider(source, provider.Tag);
+      return source == provider.Source ? provider : new TagProvider(source, provider.Tag);
     }
 
     /// <inheritdoc/>
@@ -137,14 +135,12 @@ protected override CompilableProvider VisitFilter(FilterProvider provider)
     }
 
     /// <inheritdoc/>
-    protected override DistinctProvider VisitDistinct(DistinctProvider provider)
+    protected override CompilableProvider VisitDistinct(DistinctProvider provider)
     {
       OnRecursionEntrance(provider);
       var source = VisitCompilable(provider.Source);
       OnRecursionExit(provider);
-      if (source == provider.Source)
-        return provider;
-      return new DistinctProvider(source);
+      return source == provider.Source ? provider : new DistinctProvider(source);
     }
 
     /// <inheritdoc/>
@@ -179,14 +175,14 @@ protected override CompilableProvider VisitRowNumber(RowNumberProvider provider)
 
 
     /// <inheritdoc/>
-    protected override AliasProvider VisitAlias(AliasProvider provider)
+    protected override CompilableProvider VisitAlias(AliasProvider provider)
     {
       OnRecursionEntrance(provider);
       var source = VisitCompilable(provider.Source);
       OnRecursionExit(provider);
-      if (source == provider.Source)
-        return provider;
-      return new AliasProvider(source, provider.Alias);
+      return source == provider.Source
+        ? provider
+        : new AliasProvider(source, provider.Alias);
     }
 
     /// <inheritdoc/>
@@ -207,17 +203,16 @@ protected override CompilableProvider VisitAggregate(AggregateProvider provider)
     }
 
     /// <inheritdoc/>
-    protected override StoreProvider VisitStore(StoreProvider provider)
+    protected override CompilableProvider VisitStore(StoreProvider provider)
     {
-      var compilableSource = provider.Source as CompilableProvider;
-      if (compilableSource == null)
+      if (!(provider.Source is CompilableProvider compilableSource))
         return provider;
       OnRecursionEntrance(provider);
       var source = VisitCompilable(compilableSource);
       OnRecursionExit(provider);
-      if (source == compilableSource)
-        return provider;
-      return new StoreProvider(source, provider.Name);
+      return source == compilableSource
+        ? provider
+        : new StoreProvider(source, provider.Name);
     }
 
     /// <inheritdoc/>
@@ -237,7 +232,7 @@ protected override CompilableProvider VisitFreeText(FreeTextProvider provider)
     }
 
     /// <inheritdoc/>
-    protected override ContainsTableProvider VisitContainsTable(ContainsTableProvider provider)
+    protected override CompilableProvider VisitContainsTable(ContainsTableProvider provider)
     {
       OnRecursionEntrance(provider);
       OnRecursionExit(provider);
@@ -257,14 +252,12 @@ protected override CompilableProvider VisitPredicateJoin(PredicateJoinProvider p
     }
 
     /// <inheritdoc/>
-    protected override ExistenceProvider VisitExistence(ExistenceProvider provider)
+    protected override CompilableProvider VisitExistence(ExistenceProvider provider)
     {
       OnRecursionEntrance(provider);
       var source = VisitCompilable(provider.Source);
       OnRecursionExit(provider);
-      if (source == provider.Source)
-        return provider;
-      return new ExistenceProvider(source, provider.ExistenceColumnName);
+      return source == provider.Source ? provider : new ExistenceProvider(source, provider.ExistenceColumnName);
     }
 
     /// <inheritdoc/>
@@ -328,14 +321,12 @@ protected override CompilableProvider VisitUnion(UnionProvider provider)
     }
 
     /// <inheritdoc/>
-    protected override LockProvider VisitLock(LockProvider provider)
+    protected override CompilableProvider VisitLock(LockProvider provider)
     {
       OnRecursionEntrance(provider);
       var source = VisitCompilable(provider.Source);
       OnRecursionExit(provider);
-      if (source == provider.Source)
-        return provider;
-      return new LockProvider(source, provider.LockMode, provider.LockBehavior);
+      return source == provider.Source ? provider : new LockProvider(source, provider.LockMode, provider.LockBehavior);
     }
 
     protected override CompilableProvider VisitInclude(IncludeProvider provider)

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

@@ -88,7 +88,7 @@ protected override CompilableProvider VisitFreeText(FreeTextProvider provider)
       return provider;
     }
 
-    protected override ContainsTableProvider VisitContainsTable(ContainsTableProvider provider)
+    protected override CompilableProvider VisitContainsTable(ContainsTableProvider provider)
     {
       mappings[provider] = CollectionUtils.RangeToList(0, provider.Header.Length);
       return provider;
@@ -322,7 +322,7 @@ protected override CompilableProvider VisitRowNumber(RowNumberProvider provider)
         : new RowNumberProvider(newSource, rowNumberColumn.Name);
     }
 
-    protected override StoreProvider VisitStore(StoreProvider provider)
+    protected override CompilableProvider VisitStore(StoreProvider provider)
     {
       if (!(provider.Source is CompilableProvider compilableSource)) {
         return provider;

Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/ApplyProviderCorrectorRewriter.cs

@@ -179,7 +179,7 @@ protected override CompilableProvider VisitFilter(FilterProvider provider)
       return newProvider;
     }
 
-    protected override AliasProvider VisitAlias(AliasProvider provider)
+    protected override CompilableProvider VisitAlias(AliasProvider provider)
     {
       var source = VisitCompilable(provider.Source);
       var newProvider = source!=provider.Source ? new AliasProvider(source, provider.Alias) : provider;
@@ -247,14 +247,12 @@ protected override CompilableProvider VisitExcept(ExceptProvider provider)
       return provider;
     }
 
-    protected override ConcatProvider VisitConcat(ConcatProvider provider)
+    protected override CompilableProvider VisitConcat(ConcatProvider provider)
     {
-      CompilableProvider left;
-      CompilableProvider right;
-      VisitBinaryProvider(provider, out left, out right);
-      if (left != provider.Left || right != provider.Right)
-        return new ConcatProvider(left, right);
-      return provider;
+      VisitBinaryProvider(provider, out var left, out var right);
+      return left == provider.Left && right == provider.Right
+        ? provider
+        : new ConcatProvider(left, right);
     }
 
     protected override CompilableProvider VisitUnion(UnionProvider provider)

Orm/Xtensive.Orm/Orm/Rse/Transformation/Internals/OrderingRewriter.cs

@@ -62,7 +62,7 @@ protected override CompilableProvider VisitSort(SortProvider provider)
       return source;
     }
 
-    protected override SelectProvider VisitSelect(SelectProvider provider)
+    protected override CompilableProvider VisitSelect(SelectProvider provider)
     {
       var result = provider;
       var source = VisitCompilable(provider.Source);
@@ -93,7 +93,7 @@ protected override SelectProvider VisitSelect(SelectProvider provider)
       return result;
     }
 
-    protected override AggregateProvider VisitAggregate(AggregateProvider provider)
+    protected override CompilableProvider VisitAggregate(AggregateProvider provider)
     {
       var result = provider;
       var source = VisitCompilable(provider.Source);
@@ -119,19 +119,19 @@ protected override AggregateProvider VisitAggregate(AggregateProvider provider)
       return result;
     }
 
-    protected override IndexProvider VisitIndex(IndexProvider provider)
+    protected override CompilableProvider VisitIndex(IndexProvider provider)
     {
       sortOrder = new DirectionCollection<int>();
       return provider;
     }
 
-    protected override FreeTextProvider VisitFreeText(FreeTextProvider provider)
+    protected override CompilableProvider VisitFreeText(FreeTextProvider provider)
     {
       sortOrder = new DirectionCollection<int>();
       return provider;
     }
 
-    protected override ContainsTableProvider VisitContainsTable(ContainsTableProvider provider)
+    protected override CompilableProvider VisitContainsTable(ContainsTableProvider provider)
     {
       sortOrder = new DirectionCollection<int>();
       return provider;
@@ -143,7 +143,7 @@ protected override RawProvider VisitRaw(RawProvider provider)
       return provider;
     }
 
-    protected override StoreProvider VisitStore(StoreProvider provider)
+    protected override CompilableProvider VisitStore(StoreProvider provider)
     {
       sortOrder = new DirectionCollection<int>();
       return provider;