Reapply "Add support for generic function type syntax, part 1"

pkg/analyzer/lib/src/generated/resolver.dart

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 2e1b856312f52d726e107c78bcbf743e86831b60..6e3ecfcfdb5f744d75d8850096b2936b3b3c9fae 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -372,13 +372,13 @@ class BestPracticesVerifier extends RecursiveAstVisitor<Object> {
    */
   bool _checkAllTypeChecks(IsExpression node) {
     Expression expression = node.expression;
-    TypeName typeName = node.type;
+    TypeAnnotation typeName = node.type;
     DartType lhsType = expression.staticType;
     DartType rhsType = typeName.type;
     if (lhsType == null || rhsType == null) {
       return false;
     }
-    String rhsNameStr = typeName.name.name;
+    String rhsNameStr = typeName is TypeName ? typeName.name.name : null;
     // if x is dynamic
     if (rhsType.isDynamic && rhsNameStr == Keyword.DYNAMIC.syntax) {
       if (node.notOperator == null) {
@@ -884,7 +884,7 @@ class BestPracticesVerifier extends RecursiveAstVisitor<Object> {
    * @return `true` if and only if a hint code is generated on the passed node
    * See [HintCode.MISSING_RETURN].
    */
-  void _checkForMissingReturn(TypeName returnType, FunctionBody body) {
+  void _checkForMissingReturn(TypeAnnotation returnType, FunctionBody body) {
     // Check that the method or function has a return type, and a function body
     if (returnType == null || body == null) {
       return;
@@ -1847,8 +1847,7 @@ class Dart2JSVerifier extends RecursiveAstVisitor<Object> {
    * [HintCode.IS_NOT_INT].
    */
   bool _checkForIsDoubleHints(IsExpression node) {
-    TypeName typeName = node.type;
-    DartType type = typeName.type;
+    DartType type = node.type.type;
     Element element = type?.element;
     if (element != null) {
       String typeNameStr = element.name;
@@ -3020,6 +3019,9 @@ class ExitDetector extends GeneralizingAstVisitor<bool> {
   }
 
   @override
+  bool visitGenericFunctionType(GenericFunctionType node) => false;
+
+  @override
   bool visitIdentifier(Identifier node) => false;
 
   @override
@@ -6092,6 +6094,9 @@ class ResolverVisitor extends ScopedVisitor {
   }
 
   @override
+  Object visitGenericFunctionType(GenericFunctionType node) => null;
+
+  @override
   Object visitHideCombinator(HideCombinator node) => null;
 
   @override
@@ -8025,7 +8030,7 @@ class ToDoFinder {
 }
 
 /**
- * Helper for resolving [TypeName]s.
+ * Helper for resolving types.
  *
  * The client must set [nameScope] before calling [resolveTypeName].
  */
@@ -8304,15 +8309,14 @@ class TypeNameResolver {
       return;
     }
     if (argumentList != null) {
-      NodeList<TypeName> arguments = argumentList.arguments;
+      NodeList<TypeAnnotation> arguments = argumentList.arguments;
       int argumentCount = arguments.length;
       List<DartType> parameters = typeSystem.typeFormalsAsTypes(type);
       int parameterCount = parameters.length;
       List<DartType> typeArguments = new List<DartType>(parameterCount);
       if (argumentCount == parameterCount) {
         for (int i = 0; i < parameterCount; i++) {
-          TypeName argumentTypeName = arguments[i];
-          DartType argumentType = _getType(argumentTypeName);
+          DartType argumentType = _getType(arguments[i]);
           if (argumentType == null) {
             argumentType = dynamicType;
           }
@@ -8334,16 +8338,12 @@ class TypeNameResolver {
   }
 
   /**
-   * The number of type arguments in the given type name does not match the number of parameters in
-   * the corresponding class element. Return the error code that should be used to report this
-   * error.
-   *
-   * @param node the type name with the wrong number of type arguments
-   * @return the error code that should be used to report that the wrong number of type arguments
-   *         were provided
+   * The number of type arguments in the given [typeName] does not match the
+   * number of parameters in the corresponding class element. Return the error
+   * code that should be used to report this error.
    */
-  ErrorCode _getInvalidTypeParametersErrorCode(TypeName node) {
-    AstNode parent = node.parent;
+  ErrorCode _getInvalidTypeParametersErrorCode(TypeName typeName) {
+    AstNode parent = typeName.parent;
     if (parent is ConstructorName) {
       parent = parent.parent;
       if (parent is InstanceCreationExpression) {
@@ -8358,11 +8358,7 @@ class TypeNameResolver {
   }
 
   /**
-   * Checks if the given type name is the target in a redirected constructor.
-   *
-   * @param typeName the type name to analyze
-   * @return some [RedirectingConstructorKind] if the given type name is used as the type in a
-   *         redirected constructor, or `null` otherwise
+   * Checks if the given [typeName] is the target in a redirected constructor.
    */
   RedirectingConstructorKind _getRedirectingConstructorKind(TypeName typeName) {
     AstNode parent = typeName.parent;
@@ -8381,13 +8377,10 @@ class TypeNameResolver {
   }
 
   /**
-   * Return the type represented by the given type name.
-   *
-   * @param typeName the type name representing the type to be returned
-   * @return the type represented by the type name
+   * Return the type represented by the given type [annotation].
    */
-  DartType _getType(TypeName typeName) {
-    DartType type = typeName.type;
+  DartType _getType(TypeAnnotation annotation) {
+    DartType type = annotation.type;
     if (type == null) {
       return undefinedType;
     }
@@ -8431,10 +8424,7 @@ class TypeNameResolver {
   }
 
   /**
-   * Checks if the given type name is used as the type in an as expression.
-   *
-   * @param typeName the type name to analyzer
-   * @return `true` if the given type name is used as the type in an as expression
+   * Checks if the given [typeName] is used as the type in an as expression.
    */
   bool _isTypeNameInAsExpression(TypeName typeName) {
     AstNode parent = typeName.parent;
@@ -8445,10 +8435,8 @@ class TypeNameResolver {
   }
 
   /**
-   * Checks if the given type name is used as the exception type in a catch clause.
-   *
-   * @param typeName the type name to analyzer
-   * @return `true` if the given type name is used as the exception type in a catch clause
+   * Checks if the given [typeName] is used as the exception type in a catch
+   * clause.
    */
   bool _isTypeNameInCatchClause(TypeName typeName) {
     AstNode parent = typeName.parent;
@@ -8459,11 +8447,8 @@ class TypeNameResolver {
   }
 
   /**
-   * Checks if the given type name is used as the type in an instance creation expression.
-   *
-   * @param typeName the type name to analyzer
-   * @return `true` if the given type name is used as the type in an instance creation
-   *         expression
+   * Checks if the given [typeName] is used as the type in an instance creation
+   * expression.
    */
   bool _isTypeNameInInstanceCreationExpression(TypeName typeName) {
     AstNode parent = typeName.parent;
@@ -8475,10 +8460,7 @@ class TypeNameResolver {
   }
 
   /**
-   * Checks if the given type name is used as the type in an is expression.
-   *
-   * @param typeName the type name to analyzer
-   * @return `true` if the given type name is used as the type in an is expression
+   * Checks if the given [typeName] is used as the type in an is expression.
    */
   bool _isTypeNameInIsExpression(TypeName typeName) {
     AstNode parent = typeName.parent;
@@ -8489,10 +8471,7 @@ class TypeNameResolver {
   }
 
   /**
-   * Checks if the given type name used in a type argument list.
-   *
-   * @param typeName the type name to analyzer
-   * @return `true` if the given type name is in a type argument list
+   * Checks if the given [typeName] used in a type argument list.
    */
   bool _isTypeNameInTypeArgumentList(TypeName typeName) =>
       typeName.parent is TypeArgumentList;
@@ -8515,24 +8494,24 @@ class TypeNameResolver {
   }
 
   /**
-   * @return `true` if the name of the given [TypeName] is an built-in identifier.
+   * Return `true` if the name of the given [typeName] is an built-in identifier.
    */
-  static bool _isBuiltInIdentifier(TypeName node) {
-    Token token = node.name.beginToken;
+  static bool _isBuiltInIdentifier(TypeName typeName) {
+    Token token = typeName.name.beginToken;
     return token.type == TokenType.KEYWORD;
   }
 
   /**
-   * @return `true` if given [TypeName] is used as a type annotation.
+   * @return `true` if given [typeName] is used as a type annotation.
    */
-  static bool _isTypeAnnotation(TypeName node) {
-    AstNode parent = node.parent;
+  static bool _isTypeAnnotation(TypeName typeName) {
+    AstNode parent = typeName.parent;
     if (parent is VariableDeclarationList) {
-      return identical(parent.type, node);
+      return identical(parent.type, typeName);
     } else if (parent is FieldFormalParameter) {
-      return identical(parent.type, node);
+      return identical(parent.type, typeName);
     } else if (parent is SimpleFormalParameter) {
-      return identical(parent.type, node);
+      return identical(parent.type, typeName);
     }
     return false;
   }
@@ -8800,10 +8779,15 @@ class TypeParameterBoundsResolver {
     }
   }
 
-  void _resolveTypeName(TypeName typeName) {
-    typeName.typeArguments?.arguments?.forEach(_resolveTypeName);
-    typeNameResolver.resolveTypeName(typeName);
-    // TODO(scheglov) report error when don't apply type bounds for type bounds
+  void _resolveTypeName(TypeAnnotation type) {
+    if (type is TypeName) {
+      type.typeArguments?.arguments?.forEach(_resolveTypeName);
+      typeNameResolver.resolveTypeName(type);
+      // TODO(scheglov) report error when don't apply type bounds for type bounds
+    } else {
+      // TODO(brianwilkerson) Add resolution of GenericFunctionType
+      throw new ArgumentError('Cannot resolve a ${type.runtimeType}');
+    }
   }
 
   void _resolveTypeParameters(
@@ -8811,13 +8795,19 @@ class TypeParameterBoundsResolver {
     if (typeParameters != null) {
       Scope typeParametersScope = null;
       for (TypeParameter typeParameter in typeParameters.typeParameters) {
-        TypeName bound = typeParameter.bound;
+        TypeAnnotation bound = typeParameter.bound;
         if (bound != null) {
           Element typeParameterElement = typeParameter.name.staticElement;
           if (typeParameterElement is TypeParameterElementImpl) {
             if (LibraryElementImpl.hasResolutionCapability(
                 library, LibraryResolutionCapability.resolvedTypeNames)) {
-              bound.type = typeParameterElement.bound;
+              if (bound is TypeName) {
+                bound.type = typeParameterElement.bound;
+              } else {
+                // TODO(brianwilkerson) Add resolution of GenericFunctionType
+                throw new ArgumentError(
+                    'Cannot resolve a ${bound.runtimeType}');
+              }
             } else {
               libraryScope ??= new LibraryScope(library);
               typeParametersScope ??= createTypeParametersScope();
@@ -9495,7 +9485,7 @@ class TypeResolverVisitor extends ScopedVisitor {
   TypeSystem _typeSystem;
 
   /**
-   * The helper to resolve [TypeName]s.
+   * The helper to resolve types.
    */
   TypeNameResolver _typeNameResolver;
 
@@ -9577,7 +9567,7 @@ class TypeResolverVisitor extends ScopedVisitor {
       // If an 'on' clause is provided the type of the exception parameter is
       // the type in the 'on' clause. Otherwise, the type of the exception
       // parameter is 'Object'.
-      TypeName exceptionTypeName = node.exceptionType;
+      TypeAnnotation exceptionTypeName = node.exceptionType;
       DartType exceptionType;
       if (exceptionTypeName == null) {
         exceptionType = typeProvider.dynamicType;
@@ -9716,7 +9706,7 @@ class TypeResolverVisitor extends ScopedVisitor {
   Object visitDeclaredIdentifier(DeclaredIdentifier node) {
     super.visitDeclaredIdentifier(node);
     DartType declaredType;
-    TypeName typeName = node.type;
+    TypeAnnotation typeName = node.type;
     if (typeName == null) {
       declaredType = _dynamicType;
     } else {
@@ -9735,7 +9725,7 @@ class TypeResolverVisitor extends ScopedVisitor {
       FormalParameterList parameterList = node.parameters;
       if (parameterList == null) {
         DartType type;
-        TypeName typeName = node.type;
+        TypeAnnotation typeName = node.type;
         if (typeName == null) {
           element.hasImplicitType = true;
           if (element is FieldFormalParameterElement) {
@@ -9958,7 +9948,7 @@ class TypeResolverVisitor extends ScopedVisitor {
   Object visitSimpleFormalParameter(SimpleFormalParameter node) {
     super.visitSimpleFormalParameter(node);
     DartType declaredType;
-    TypeName typeName = node.type;
+    TypeAnnotation typeName = node.type;
     if (typeName == null) {
       declaredType = _dynamicType;
     } else {
@@ -9997,7 +9987,7 @@ class TypeResolverVisitor extends ScopedVisitor {
       // Bounds of parameters of classes and function type aliases are
       // already resolved.
     } else {
-      TypeName bound = node.bound;
+      TypeAnnotation bound = node.bound;
       if (bound != null) {
         TypeParameterElementImpl typeParameter =
             node.name.staticElement as TypeParameterElementImpl;
@@ -10022,7 +10012,7 @@ class TypeResolverVisitor extends ScopedVisitor {
     }
     // Resolve the type.
     DartType declaredType;
-    TypeName typeName = variableList.type;
+    TypeAnnotation typeName = variableList.type;
     if (typeName == null) {
       declaredType = _dynamicType;
     } else {
@@ -10036,13 +10026,10 @@ class TypeResolverVisitor extends ScopedVisitor {
   }
 
   /**
-   * Given a type name representing the return type of a function, compute the return type of the
+   * Given the [returnType] of a function, compute the return type of the
    * function.
-   *
-   * @param returnType the type name representing the return type of the function
-   * @return the return type that was computed
    */
-  DartType _computeReturnType(TypeName returnType) {
+  DartType _computeReturnType(TypeAnnotation returnType) {
     if (returnType == null) {
       return _dynamicType;
     } else {
@@ -10124,13 +10111,8 @@ class TypeResolverVisitor extends ScopedVisitor {
   }
 
   /**
-   * Resolve the types in the given with and implements clauses and associate those types with the
-   * given class element.
-   *
-   * @param classElement the class element with which the mixin and interface types are to be
-   *          associated
-   * @param withClause the with clause to be resolved
-   * @param implementsClause the implements clause to be resolved
+   * Resolve the types in the given [withClause] and [implementsClause] and
+   * associate those types with the given [classElement].
    */
   void _resolve(ClassElementImpl classElement, WithClause withClause,
       ImplementsClause implementsClause) {
@@ -10239,15 +10221,12 @@ class TypeResolverVisitor extends ScopedVisitor {
   }
 
   /**
-   * Given a parameter element, create a function type based on the given return type and parameter
-   * list and associate the created type with the element.
-   *
-   * @param element the parameter element whose type is to be set
-   * @param returnType the (possibly `null`) return type of the function
-   * @param parameterList the list of parameters to the function
+   * Given a parameter [element], create a function type based on the given
+   * [returnType] and [parameterList] and associate the created type with the
+   * element.
    */
   void _setFunctionTypedParameterType(ParameterElementImpl element,
-      TypeName returnType, FormalParameterList parameterList) {
+      TypeAnnotation returnType, FormalParameterList parameterList) {
     List<ParameterElement> parameters = _getElements(parameterList);
     FunctionElementImpl functionElement = new FunctionElementImpl.forNode(null);
     functionElement.isSynthetic = true;