Make TypeSystemImpl getters for nullable num/int/double.

Change-Id: Ic6fe64f206c3273c9e5c4a688b6a8fe32a78d1fa
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/159963
Commit-Queue: Paul Berry <[email protected]>
Reviewed-by: Konstantin Shcheglov <[email protected]>

Author: stereotype441

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

@@ -1305,7 +1305,7 @@ class InterfaceTypeImpl extends TypeImpl implements InterfaceType {
   }
 
   @override
-  TypeImpl withNullability(NullabilitySuffix nullabilitySuffix) {
+  InterfaceTypeImpl withNullability(NullabilitySuffix nullabilitySuffix) {
     if (this.nullabilitySuffix == nullabilitySuffix) return this;
 
     return InterfaceTypeImpl(

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

@@ -57,16 +57,19 @@ class TypeProviderImpl extends TypeProviderBase {
   InterfaceType _boolType;
   InterfaceType _deprecatedType;
   InterfaceType _doubleType;
+  InterfaceType _doubleTypeQuestion;
   InterfaceType _functionType;
   InterfaceType _futureDynamicType;
   InterfaceType _futureNullType;
   InterfaceType _futureOrNullType;
   InterfaceType _intType;
+  InterfaceType _intTypeQuestion;
   InterfaceType _iterableDynamicType;
   InterfaceType _iterableObjectType;
   InterfaceType _mapObjectObjectType;
   InterfaceType _nullType;
   InterfaceType _numType;
+  InterfaceType _numTypeQuestion;
   InterfaceType _objectType;
   InterfaceType _stackTraceType;
   InterfaceType _streamDynamicType;
@@ -148,6 +151,10 @@ class TypeProviderImpl extends TypeProviderBase {
     return _doubleType;
   }
 
+  InterfaceType get doubleTypeQuestion =>
+      _doubleTypeQuestion ??= (doubleType as InterfaceTypeImpl)
+          .withNullability(NullabilitySuffix.question);
+
   @override
   DartType get dynamicType => DynamicTypeImpl.instance;
 
@@ -208,6 +215,10 @@ class TypeProviderImpl extends TypeProviderBase {
     return _intType;
   }
 
+  InterfaceType get intTypeQuestion =>
+      _intTypeQuestion ??= (intType as InterfaceTypeImpl)
+          .withNullability(NullabilitySuffix.question);
+
   @override
   InterfaceType get iterableDynamicType {
     _iterableDynamicType ??= InterfaceTypeImpl(
@@ -298,6 +309,10 @@ class TypeProviderImpl extends TypeProviderBase {
     return _numType;
   }
 
+  InterfaceType get numTypeQuestion =>
+      _numTypeQuestion ??= (numType as InterfaceTypeImpl)
+          .withNullability(NullabilitySuffix.question);
+
   ClassElement get objectElement {
     return _objectElement ??= _getClassElement(_coreLibrary, 'Object');
   }

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

@@ -25,6 +25,7 @@ import 'package:analyzer/src/dart/element/subtype.dart';
 import 'package:analyzer/src/dart/element/top_merge.dart';
 import 'package:analyzer/src/dart/element/type.dart';
 import 'package:analyzer/src/dart/element/type_algebra.dart';
+import 'package:analyzer/src/dart/element/type_provider.dart';
 import 'package:analyzer/src/dart/element/type_schema.dart';
 import 'package:analyzer/src/dart/element/type_schema_elimination.dart';
 import 'package:meta/meta.dart';
@@ -424,7 +425,7 @@ class TypeSystemImpl extends TypeSystem2 {
   bool strictInference;
 
   @override
-  final TypeProvider typeProvider;
+  final TypeProviderImpl typeProvider;
 
   /// The cached instance of `Object?`.
   InterfaceTypeImpl _objectQuestion;
@@ -448,8 +449,9 @@ class TypeSystemImpl extends TypeSystem2 {
     @required this.implicitCasts,
     @required bool isNonNullableByDefault,
     @required this.strictInference,
-    @required this.typeProvider,
-  }) : super(isNonNullableByDefault: isNonNullableByDefault) {
+    @required TypeProvider typeProvider,
+  })  : typeProvider = typeProvider as TypeProviderImpl,
+        super(isNonNullableByDefault: isNonNullableByDefault) {
     _greatestLowerBoundHelper = GreatestLowerBoundHelper(this);
     _leastUpperBoundHelper = LeastUpperBoundHelper(this);
     _subtypeHelper = SubtypeHelper(this);
@@ -1591,29 +1593,26 @@ class TypeSystemImpl extends TypeSystem2 {
       var t = targetType;
       assert(!t.isBottom);
       var numType = typeProvider.numType;
-      var numTypeQuestion = makeNullable(numType as InterfaceTypeImpl);
-      if (isSubtypeOf(t, numTypeQuestion)) {
+      if (isSubtypeOf(t, typeProvider.numTypeQuestion)) {
         // Then:
         // - If int <: C, not num <: C, and T <: int, then the context type of
         //   e2 is int.
         // (Note: as above, we check the type of T against `int?`, because it's
         // equivalent and leads to better error recovery.)
         var intType = typeProvider.intType;
-        var intTypeQuestion = makeNullable(intType as InterfaceTypeImpl);
         if (isSubtypeOf(intType, c) &&
             !isSubtypeOf(numType, c) &&
-            isSubtypeOf(t, intTypeQuestion)) {
+            isSubtypeOf(t, typeProvider.intTypeQuestion)) {
           return intType;
         }
         // - If double <: C, not num <: C, and not T <: double, then the context
         //   type of e2 is double.
         // (Note: as above, we check the type of T against `double?`, because
         // it's equivalent and leads to better error recovery.)
         var doubleType = typeProvider.doubleType;
-        var doubleTypeQuestion = makeNullable(doubleType as InterfaceTypeImpl);
         if (isSubtypeOf(doubleType, c) &&
             !isSubtypeOf(numType, c) &&
-            !isSubtypeOf(t, doubleTypeQuestion)) {
+            !isSubtypeOf(t, typeProvider.doubleTypeQuestion)) {
           return doubleType;
         }
         // Otherwise, the context type of e2 is num.
@@ -1638,27 +1637,24 @@ class TypeSystemImpl extends TypeSystem2 {
       var t = targetType;
       assert(!t.isBottom);
       var numType = typeProvider.numType;
-      var numTypeQuestion = makeNullable(numType as InterfaceTypeImpl);
-      if (isSubtypeOf(t, numTypeQuestion)) {
+      if (isSubtypeOf(t, typeProvider.numTypeQuestion)) {
         // Then:
         // - If int <: C, not num <: C, and T <: int, then the context type of
         //   e2 and e3 is int.
         // (Note: as above, we check the type of T against `int?`, because it's
         // equivalent and leads to better error recovery.)
         var intType = typeProvider.intType;
-        var intTypeQuestion = makeNullable(intType as InterfaceTypeImpl);
         if (isSubtypeOf(intType, c) &&
             !isSubtypeOf(numType, c) &&
-            isSubtypeOf(t, intTypeQuestion)) {
+            isSubtypeOf(t, typeProvider.intTypeQuestion)) {
           return intType;
         }
         // - If double <: C, not num <: C, and T <: double, then the context
         //   type of e2 and e3 is double.
         var doubleType = typeProvider.doubleType;
-        var doubleTypeQuestion = makeNullable(doubleType as InterfaceTypeImpl);
         if (isSubtypeOf(doubleType, c) &&
             !isSubtypeOf(numType, c) &&
-            isSubtypeOf(t, doubleTypeQuestion)) {
+            isSubtypeOf(t, typeProvider.doubleTypeQuestion)) {
           return doubleType;
         }
         // - Otherwise the context type of e2 an e3 is num.
@@ -1695,9 +1691,7 @@ class TypeSystemImpl extends TypeSystem2 {
       //   `int? + int` to resolve to `int` rather than `num`).
       var t = targetType;
       assert(!t.isBottom);
-      var numType = typeProvider.numType;
-      var numTypeQuestion = makeNullable(numType as InterfaceTypeImpl);
-      if (isSubtypeOf(t, numTypeQuestion)) {
+      if (isSubtypeOf(t, typeProvider.numTypeQuestion)) {
         // ...and where the static type of e2 is S and S is assignable to num.
         // (Note: we don't have to check that S is assignable to num because
         // this is required by the signature of the method.)
@@ -1709,8 +1703,7 @@ class TypeSystemImpl extends TypeSystem2 {
           // (Note: as above, we check against `double?` because it's equivalent
           // and leads to better error recovery.)
           var doubleType = typeProvider.doubleType;
-          var doubleTypeQuestion =
-              makeNullable(doubleType as InterfaceTypeImpl);
+          var doubleTypeQuestion = typeProvider.doubleTypeQuestion;
           if (isSubtypeOf(t, doubleTypeQuestion)) {
             return doubleType;
           }
@@ -1723,15 +1716,14 @@ class TypeSystemImpl extends TypeSystem2 {
           // - If T <: int, S <: int and not S <: Never, then the static type of
           //   e is int.
           // (As above, we check against `int?` for error recovery.)
-          var intType = typeProvider.intType;
-          var intTypeQuestion = makeNullable(intType as InterfaceTypeImpl);
+          var intTypeQuestion = typeProvider.intTypeQuestion;
           if (!s.isBottom &&
               isSubtypeOf(t, intTypeQuestion) &&
               isSubtypeOf(s, intTypeQuestion)) {
-            return intType;
+            return typeProvider.intType;
           }
           // - Otherwise the static type of e is num.
-          return numType;
+          return typeProvider.numType;
         }
       }
     }
@@ -1755,8 +1747,7 @@ class TypeSystemImpl extends TypeSystem2 {
         //   `int?.clamp(int, int)` to resolve to `int` rather than `num`).
         // - We don't check that T2 and T3 are subtypes of num because the
         //   signature of `num.clamp` requires it.
-        var numType = typeProvider.numType;
-        var numTypeQuestion = makeNullable(numType as InterfaceTypeImpl);
+        var numTypeQuestion = typeProvider.numTypeQuestion;
         if (isSubtypeOf(t1, numTypeQuestion) && !t2.isBottom && !t3.isBottom) {
           assert(!t1.isBottom);
           assert(isSubtypeOf(t2, numTypeQuestion));
@@ -1766,26 +1757,23 @@ class TypeSystemImpl extends TypeSystem2 {
           //   int.
           // (Note: as above, we check against `int?` because it's equivalent
           // and leads to better error recovery.)
-          var intType = typeProvider.intType;
-          var intTypeQuestion = makeNullable(intType as InterfaceTypeImpl);
+          var intTypeQuestion = typeProvider.intTypeQuestion;
           if (isSubtypeOf(t1, intTypeQuestion) &&
               isSubtypeOf(t2, intTypeQuestion) &&
               isSubtypeOf(t3, intTypeQuestion)) {
-            return intType;
+            return typeProvider.intType;
           }
           // If T1, T2 and T3 are all subtypes of double, the static type of e
           // is double.
           // (As above, we check against `double?` for error recovery.)
-          var doubleType = typeProvider.doubleType;
-          var doubleTypeQuestion =
-              makeNullable(doubleType as InterfaceTypeImpl);
+          var doubleTypeQuestion = typeProvider.doubleTypeQuestion;
           if (isSubtypeOf(t1, doubleTypeQuestion) &&
               isSubtypeOf(t2, doubleTypeQuestion) &&
               isSubtypeOf(t3, doubleTypeQuestion)) {
-            return doubleType;
+            return typeProvider.doubleType;
           }
           // Otherwise the static type of e is num.
-          return numType;
+          return typeProvider.numType;
         }
       }
     }