Remove more type casts

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

 // Copyright (c) 2016, 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.
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/src/dart/ast/token.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/member.dart';
 import 'package:analyzer/src/dart/element/type.dart';
 import 'package:analyzer/src/generated/error.dart';
+import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/generated/type_system.dart';
 import 'package:analyzer/src/generated/utilities_dart.dart';
 
 /**
  * Instances of the class `InheritanceManager` manage the knowledge of where class members
  * (methods, getters & setters) are inherited from.
  */
 class InheritanceManager {
   /**
    * The [LibraryElement] that is managed by this manager.
@@ skipping 793 matching lines @@
 
   /**
    * Loop through all of the members in the given [map], performing type
    * parameter  substitutions using a passed [supertype].
    */
   void _substituteTypeParametersDownHierarchy(
       InterfaceType superType, Map<String, ExecutableElement> map) {
     for (String memberName in map.keys) {
       ExecutableElement executableElement = map[memberName];
       if (executableElement is MethodMember) {
-        executableElement =
-            MethodMember.from(executableElement as MethodMember, superType);
-        map[memberName] = executableElement;
+        map[memberName] = MethodMember.from(executableElement, superType);
       } else if (executableElement is PropertyAccessorMember) {
-        executableElement = PropertyAccessorMember.from(
-            executableElement as PropertyAccessorMember, superType);
-        map[memberName] = executableElement;
+        map[memberName] =
+            PropertyAccessorMember.from(executableElement, superType);
       }
     }
   }
 
   /**
    * Union all of the [lookupMaps] together into a single map, grouping the ExecutableElements
    * into a list where none of the elements are equal where equality is determined by having equal
    * function types. (We also take note too of the kind of the element: ()->int and () -> int may
    * not be equal if one is a getter and the other is a method.)
    *
@@ skipping 103 matching lines @@
     DynamicTypeImpl dynamicType = DynamicTypeImpl.instance;
     SimpleIdentifier nameIdentifier =
         new SimpleIdentifier(new StringToken(TokenType.IDENTIFIER, name, 0));
     ExecutableElementImpl executable;
     ExecutableElement elementToMerge = elementArrayToMerge[0];
     if (elementToMerge is MethodElement) {
       MultiplyInheritedMethodElementImpl unionedMethod =
           new MultiplyInheritedMethodElementImpl(nameIdentifier);
       unionedMethod.inheritedElements = elementArrayToMerge;
       executable = unionedMethod;
-    } else {
+    } else if (elementToMerge is PropertyAccessorElement) {
       MultiplyInheritedPropertyAccessorElementImpl unionedPropertyAccessor =
           new MultiplyInheritedPropertyAccessorElementImpl(nameIdentifier);
-      unionedPropertyAccessor.getter =
-          (elementToMerge as PropertyAccessorElement).isGetter;
-      unionedPropertyAccessor.setter =
-          (elementToMerge as PropertyAccessorElement).isSetter;
+      unionedPropertyAccessor.getter = elementToMerge.isGetter;
+      unionedPropertyAccessor.setter = elementToMerge.isSetter;
       unionedPropertyAccessor.inheritedElements = elementArrayToMerge;
       executable = unionedPropertyAccessor;
+    } else {
+      throw new AnalysisException(
+          'Invalid class of element in merge: ${elementToMerge.runtimeType}');
     }
     int numOfParameters = numOfRequiredParameters +
         numOfPositionalParameters +
         namedParameters.length;
     List<ParameterElement> parameters =
         new List<ParameterElement>(numOfParameters);
     int i = 0;
     for (int j = 0; j < numOfRequiredParameters; j++, i++) {
       ParameterElementImpl parameter = new ParameterElementImpl("", 0);
       parameter.type = dynamicType;
@@ skipping 253 matching lines @@
   }
 
   /**
    * Initializes [keys] and [values].
    */
   void _initArrays(int initialCapacity) {
     _keys = new List<String>(initialCapacity);
     _values = new List<ExecutableElement>(initialCapacity);
   }
 }