Use mapFunctionType() and mapInterfaceType().

Change-Id: I40429adac947a86e2ff7c84ff6c8473f8c73f931
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/417104
Reviewed-by: Paul Berry <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/lib/src/dart/constant/evaluation.dart

@@ -2041,8 +2041,7 @@ class ConstantVisitor extends UnifyingAstVisitor<Constant> {
             functionElement.type.instantiate(typeArgumentTypes);
         var substitution = _substitution;
         if (substitution != null) {
-          instantiatedType =
-              substitution.substituteType(instantiatedType) as FunctionTypeImpl;
+          instantiatedType = substitution.mapFunctionType(instantiatedType);
         }
         return value.typeInstantiate(
             typeSystem, instantiatedType, typeArgumentTypes);

pkg/analyzer/lib/src/dart/element/class_hierarchy.dart

@@ -63,8 +63,7 @@ class ClassHierarchy {
       var element = type.element3;
       var rawInterfaces = implementedInterfaces(element);
       for (var rawInterface in rawInterfaces) {
-        var newInterface =
-            substitution.substituteType(rawInterface) as InterfaceTypeImpl;
+        var newInterface = substitution.mapInterfaceType(rawInterface);
         interfacesMerger.add(newInterface);
       }
     }

pkg/analyzer/lib/src/dart/element/member.dart

@@ -329,10 +329,7 @@ abstract class ExecutableMember extends Member
 
   @override
   FunctionTypeImpl get type {
-    if (_type != null) return _type!;
-
-    _type = substitution.substituteType(declaration.type) as FunctionTypeImpl;
-    return _type!;
+    return _type ??= substitution.mapFunctionType(declaration.type);
   }
 
   @override

pkg/analyzer/lib/src/dart/element/subtype.dart

@@ -466,8 +466,7 @@ class SubtypeHelper {
     for (var interface in subElement.allSupertypes) {
       if (identical(interface.element3, superElement)) {
         var substitution = Substitution.fromInterfaceType(subType);
-        var substitutedInterface =
-            substitution.substituteType(interface) as InterfaceTypeImpl;
+        var substitutedInterface = substitution.mapInterfaceType(interface);
         return _interfaceArguments(
           superElement,
           substitutedInterface,

pkg/analyzer/lib/src/dart/element/type.dart

@@ -652,10 +652,11 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
   @override
   List<InterfaceTypeImpl> get allSupertypes {
     var substitution = Substitution.fromInterfaceType(this);
-    return element3.allSupertypes
-        .map((t) => (substitution.substituteType(t) as InterfaceTypeImpl)
-            .withNullability(nullabilitySuffix))
-        .toList();
+    return element3.allSupertypes.map((interface) {
+      return substitution
+          .mapInterfaceType(interface)
+          .withNullability(nullabilitySuffix);
+    }).toList();
   }
 
   @Deprecated('Use constructors2 instead')
@@ -823,8 +824,8 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
       return null;
     }
 
-    return (Substitution.fromInterfaceType(this).substituteType(supertype)
-            as InterfaceTypeImpl)
+    return Substitution.fromInterfaceType(this)
+        .mapInterfaceType(supertype)
         .withNullability(nullabilitySuffix);
   }
 
@@ -887,7 +888,7 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
     for (var rawInterface in element.allSupertypes) {
       if (rawInterface.element == targetElement) {
         var substitution = Substitution.fromInterfaceType(this);
-        return substitution.substituteType(rawInterface) as InterfaceTypeImpl;
+        return substitution.mapInterfaceType(rawInterface);
       }
     }
 
@@ -903,7 +904,7 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
     for (var rawInterface in element3.allSupertypes) {
       if (rawInterface.element3 == targetElement) {
         var substitution = Substitution.fromInterfaceType(this);
-        return substitution.substituteType(rawInterface) as InterfaceTypeImpl;
+        return substitution.mapInterfaceType(rawInterface);
       }
     }
 

pkg/analyzer/lib/src/dart/element/type_algebra.dart

@@ -154,6 +154,10 @@ abstract class Substitution {
 
   DartType? getSubstitute(TypeParameterElement2 parameter, bool upperBound);
 
+  FunctionTypeImpl mapFunctionType(FunctionType type) {
+    return substituteType(type) as FunctionTypeImpl;
+  }
+
   InterfaceTypeImpl mapInterfaceType(InterfaceType type) {
     return substituteType(type) as InterfaceTypeImpl;
   }

pkg/analyzer/lib/src/dart/element/type_constraint_gatherer.dart

@@ -192,9 +192,7 @@ class TypeConstraintGatherer extends shared.TypeConstraintGenerator<
     for (var interface in type.element3.allSupertypes) {
       if (interface.element3 == typeDeclaration) {
         var substitution = Substitution.fromInterfaceType(type);
-        var substitutedInterface =
-            substitution.substituteType(interface) as InterfaceTypeImpl;
-        return substitutedInterface.typeArguments;
+        return substitution.mapInterfaceType(interface).typeArguments;
       }
     }
     return null;