fixes #25477, downward inference of generic methods

pkg/analyzer/lib/src/dart/ast/ast.dart

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.src.dart.ast.ast;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
@@ skipping 5036 matching lines @@
 
 /**
  * The invocation of a function resulting from evaluating an expression.
  * Invocations of methods and other forms of functions are represented by
  * [MethodInvocation] nodes. Invocations of getters and setters are represented
  * by either [PrefixedIdentifier] or [PropertyAccess] nodes.
  *
  * > functionExpressionInvocation ::=
  * >     [Expression] [TypeArgumentList]? [ArgumentList]
  */
-class FunctionExpressionInvocationImpl extends ExpressionImpl
+class FunctionExpressionInvocationImpl extends InvocationExpressionImpl
     implements FunctionExpressionInvocation {
   /**
    * The expression producing the function being invoked.
    */
   Expression _function;
 
   /**
-   * The type arguments to be applied to the method being invoked, or `null` if
-   * no type arguments were provided.
-   */
-  TypeArgumentList _typeArguments;
-
-  /**
-   * The list of arguments to the function.
-   */
-  ArgumentList _argumentList;
-
-  /**
    * The element associated with the function being invoked based on static type
    * information, or `null` if the AST structure has not been resolved or the
    * function could not be resolved.
    */
   ExecutableElement staticElement;
 
   /**
-   * The function type of the method invocation, or `null` if the AST
-   * structure has not been resolved, or if the invoke could not be resolved.
-   *
-   * This will usually be a [FunctionType], but it can also be an
-   * [InterfaceType] with a `call` method, `dynamic`, `Function`, or a `@proxy`
-   * interface type that implements `Function`.
-   */
-  DartType staticInvokeType;
-
-  /**
    * The element associated with the function being invoked based on propagated
    * type information, or `null` if the AST structure has not been resolved or
    * the function could not be resolved.
    */
   ExecutableElement propagatedElement;
 
   /**
-   * Like [staticInvokeType], but reflects propagated type information.
-   */
-  DartType propagatedInvokeType;
-
-  /**
    * Initialize a newly created function expression invocation.
    */
   FunctionExpressionInvocationImpl(Expression function,
-      TypeArgumentList typeArguments, ArgumentList argumentList) {
+      TypeArgumentList typeArguments, ArgumentList argumentList)
+      : super(typeArguments, argumentList) {
     _function = _becomeParentOf(function);
-    _typeArguments = _becomeParentOf(typeArguments);
-    _argumentList = _becomeParentOf(argumentList);
   }
 
   @override
-  ArgumentList get argumentList => _argumentList;
-
-  @override
-  void set argumentList(ArgumentList argumentList) {
-    _argumentList = _becomeParentOf(argumentList);
-  }
-
-  @override
   Token get beginToken => _function.beginToken;
 
   @override
   ExecutableElement get bestElement {
     ExecutableElement element = propagatedElement;
     if (element == null) {
       element = staticElement;
     }
     return element;
   }
@@ skipping 10 matching lines @@
 
   @override
   void set function(Expression expression) {
     _function = _becomeParentOf(expression);
   }
 
   @override
   int get precedence => 15;
 
   @override
-  TypeArgumentList get typeArguments => _typeArguments;
-
-  @override
-  void set typeArguments(TypeArgumentList typeArguments) {
-    _typeArguments = _becomeParentOf(typeArguments);
-  }
-
-  @override
   accept(AstVisitor visitor) => visitor.visitFunctionExpressionInvocation(this);
 
   @override
   void visitChildren(AstVisitor visitor) {
     _safelyVisitChild(_function, visitor);
     _safelyVisitChild(_typeArguments, visitor);
     _safelyVisitChild(_argumentList, visitor);
   }
 }
 
@@ skipping 989 matching lines @@
   Token get endToken => contents;
 
   @override
   accept(AstVisitor visitor) => visitor.visitInterpolationString(this);
 
   @override
   void visitChildren(AstVisitor visitor) {}
 }
 
 /**
+ * Common base class for [FunctionExpressionInvocationImpl] and
+ * [MethodInvocationImpl].
+ */
+abstract class InvocationExpressionImpl extends ExpressionImpl
+    implements InvocationExpression {
+  /**
+   * The type arguments to be applied to the method being invoked, or `null` if
+   * no type arguments were provided.
+   */
+  TypeArgumentList _typeArguments;
+
+  /**
+   * The list of arguments to the function.
+   */
+  ArgumentList _argumentList;
+
+  @override
+  DartType propagatedInvokeType;
+
+  @override
+  DartType staticInvokeType;
+
+  /**
+   * Initialize a newly created invocation.
+   */
+  InvocationExpressionImpl(
+      TypeArgumentList typeArguments, ArgumentList argumentList) {
+    _typeArguments = _becomeParentOf(typeArguments);
+    _argumentList = _becomeParentOf(argumentList);
+  }
+
+  @override
+  ArgumentList get argumentList => _argumentList;
+
+  @override
+  void set argumentList(ArgumentList argumentList) {
+    _argumentList = _becomeParentOf(argumentList);
+  }
+
+  @override
+  TypeArgumentList get typeArguments => _typeArguments;
+
+  @override
+  void set typeArguments(TypeArgumentList typeArguments) {
+    _typeArguments = _becomeParentOf(typeArguments);
+  }
+}
+
+/**
  * An is expression.
  *
  * > isExpression ::=
  * >     [Expression] 'is' '!'? [TypeName]
  */
 class IsExpressionImpl extends ExpressionImpl implements IsExpression {
   /**
    * The expression used to compute the value whose type is being tested.
    */
   Expression _expression;
@@ skipping 772 matching lines @@
 
 /**
  * The invocation of either a function or a method. Invocations of functions
  * resulting from evaluating an expression are represented by
  * [FunctionExpressionInvocation] nodes. Invocations of getters and setters are
  * represented by either [PrefixedIdentifier] or [PropertyAccess] nodes.
  *
  * > methodInvocation ::=
  * >     ([Expression] '.')? [SimpleIdentifier] [TypeArgumentList]? [ArgumentList]
  */
-class MethodInvocationImpl extends ExpressionImpl implements MethodInvocation {
+class MethodInvocationImpl extends InvocationExpressionImpl
+    implements MethodInvocation {
   /**
    * The expression producing the object on which the method is defined, or
    * `null` if there is no target (that is, the target is implicitly `this`).
    */
   Expression _target;
 
   /**
    * The operator that separates the target from the method name, or `null`
    * if there is no target. In an ordinary method invocation this will be a
    * period ('.'). In a cascade section this will be the cascade operator
    * ('..').
    */
   Token operator;
 
   /**
    * The name of the method being invoked.
    */
   SimpleIdentifier _methodName;
 
   /**
-   * The type arguments to be applied to the method being invoked, or `null` if
-   * no type arguments were provided.
-   */
-  TypeArgumentList _typeArguments;
-
-  /**
-   * The list of arguments to the method.
-   */
-  ArgumentList _argumentList;
-
-  /**
-   * The function type of the method invocation, or `null` if the AST
-   * structure has not been resolved, or if the invoke could not be resolved.
-   *
-   * This will usually be a [FunctionType], but it can also be an
-   * [InterfaceType] with a `call` method, `dynamic`, `Function`, or a `@proxy`
-   * interface type that implements `Function`.
-   */
-  DartType staticInvokeType;
-
-  /**
-   * Like [staticInvokeType], but reflects propagated type information.
-   */
-  DartType propagatedInvokeType;
-
-  /**
    * Initialize a newly created method invocation. The [target] and [operator]
    * can be `null` if there is no target.
    */
   MethodInvocationImpl(
       Expression target,
       this.operator,
       SimpleIdentifier methodName,
       TypeArgumentList typeArguments,
-      ArgumentList argumentList) {
+      ArgumentList argumentList)
+      : super(typeArguments, argumentList) {
     _target = _becomeParentOf(target);
     _methodName = _becomeParentOf(methodName);
-    _typeArguments = _becomeParentOf(typeArguments);
-    _argumentList = _becomeParentOf(argumentList);
   }
 
   @override
-  ArgumentList get argumentList => _argumentList;
-
-  @override
-  void set argumentList(ArgumentList argumentList) {
-    _argumentList = _becomeParentOf(argumentList);
-  }
-
-  @override
   Token get beginToken {
     if (_target != null) {
       return _target.beginToken;
     } else if (operator != null) {
       return operator;
     }
     return _methodName.beginToken;
   }
 
   @override
   Iterable get childEntities => new ChildEntities()
     ..add(_target)
     ..add(operator)
     ..add(_methodName)
     ..add(_argumentList);
 
   @override
   Token get endToken => _argumentList.endToken;
 
   @override
+  Expression get function => methodName;
+
+  @override
   bool get isCascaded =>
       operator != null && operator.type == TokenType.PERIOD_PERIOD;
 
   @override
   SimpleIdentifier get methodName => _methodName;
 
   @override
   void set methodName(SimpleIdentifier identifier) {
     _methodName = _becomeParentOf(identifier);
   }
@@ skipping 18 matching lines @@
 
   @override
   Expression get target => _target;
 
   @override
   void set target(Expression expression) {
     _target = _becomeParentOf(expression);
   }
 
   @override
-  TypeArgumentList get typeArguments => _typeArguments;
-
-  @override
-  void set typeArguments(TypeArgumentList typeArguments) {
-    _typeArguments = _becomeParentOf(typeArguments);
-  }
-
-  @override
   accept(AstVisitor visitor) => visitor.visitMethodInvocation(this);
 
   @override
   void visitChildren(AstVisitor visitor) {
     _safelyVisitChild(_target, visitor);
     _safelyVisitChild(_methodName, visitor);
     _safelyVisitChild(_typeArguments, visitor);
     _safelyVisitChild(_argumentList, visitor);
   }
 }
@@ skipping 3739 matching lines @@
   }
 
   @override
   accept(AstVisitor visitor) => visitor.visitYieldStatement(this);
 
   @override
   void visitChildren(AstVisitor visitor) {
     _safelyVisitChild(_expression, visitor);
   }
 }