Remove unnecessary casts and general code clean-up

pkg/analyzer/lib/src/dart/element/element.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.element.element;
 
 import 'dart:collection';
 import 'dart:math' show min;
 
 import 'package:analyzer/dart/ast/ast.dart';
@@ skipping 1700 matching lines @@
       if (element is ConstructorElement) {
         return element.enclosingElement.name == _DEPRECATED_CLASS_NAME;
       } else if (element is PropertyAccessorElement) {
         return element.name == _DEPRECATED_VARIABLE_NAME;
       }
     }
     return false;
   }
 
   @override
-  bool get isJS => element is ConstructorElement &&
-        element.enclosingElement.name == _JS_CLASS_NAME &&
-        element.library?.name == _JS_LIB_NAME;
+  bool get isJS =>
+      element is ConstructorElement &&
+      element.enclosingElement.name == _JS_CLASS_NAME &&
+      element.library?.name == _JS_LIB_NAME;
 
   @override
   bool get isMustCallSuper =>
       element is PropertyAccessorElement &&
       element.name == _MUST_CALL_SUPER_VARIABLE_NAME &&
       element.library?.name == _META_LIB_NAME;
 
   @override
   bool get isOverride =>
       element is PropertyAccessorElement &&
@@ skipping 1542 matching lines @@
   /**
    * Initialize a newly created library element in the given [context] to have
    * the given [name].
    */
   LibraryElementImpl.forNode(this.context, LibraryIdentifier name)
       : nameLength = name != null ? name.length : 0,
         super.forNode(name);
 
   @override
   int get codeLength {
-    if (_definingCompilationUnit is CompilationUnitElementImpl) {
-      return (_definingCompilationUnit as CompilationUnitElementImpl)
-          .codeLength;
+    CompilationUnitElement unit = _definingCompilationUnit;
+    if (unit is CompilationUnitElementImpl) {
+      return unit.codeLength;
     }
     return null;
   }
 
   @override
   int get codeOffset {
-    if (_definingCompilationUnit is CompilationUnitElementImpl) {
-      return (_definingCompilationUnit as CompilationUnitElementImpl)
-          .codeOffset;
+    CompilationUnitElement unit = _definingCompilationUnit;
+    if (unit is CompilationUnitElementImpl) {
+      return unit.codeOffset;
     }
     return null;
   }
 
   @override
   CompilationUnitElement get definingCompilationUnit =>
       _definingCompilationUnit;
 
   /**
    * Set the compilation unit that defines this library to the given compilation
@@ skipping 369 matching lines @@
     // represents a new back edge.  It would be sufficient to invalidate the
     // cycle information for all nodes that are between the target and the
     // node in the topological order.  For simplicity, we simply invalidate
     // all nodes which are reachable from the the source node.
     // Note that in the invalidation phase, we do not cut off when we encounter
     // a node with no library cycle information, since we do not know whether
     // we are in the case where invalidation has already been performed, or we
     // are in the case where library cycles have simply never been computed from
     // a newly reachable node.
     Set<LibraryElementImpl> active = new HashSet();
-    void invalidate(LibraryElement library) {
-      if (library is LibraryElementHandle) {
-        library = (library as LibraryElementHandle).actualElement;
-      }
-      LibraryElementImpl libraryImpl = library;
-      if (active.add(libraryImpl)) {
-        if (libraryImpl._libraryCycle != null) {
-          libraryImpl._libraryCycle.forEach(invalidate);
-          libraryImpl._libraryCycle = null;
+    void invalidate(LibraryElement element) {
+      LibraryElementImpl library =
+          element is LibraryElementHandle ? element.actualElement : element;
+      if (active.add(library)) {
+        if (library._libraryCycle != null) {
+          library._libraryCycle.forEach(invalidate);
+          library._libraryCycle = null;
         }
         library.exportedLibraries.forEach(invalidate);
         library.importedLibraries.forEach(invalidate);
       }
     }
     invalidate(this);
   }
 
   @override
   bool isUpToDate(int timeStamp) {
@@ skipping 987 matching lines @@
     super.appendTo(buffer);
   }
 
   @override
   AstNode computeNode() {
     if (isSynthetic) {
       return null;
     }
     if (enclosingElement is ClassElement) {
       return getNodeMatching((node) => node is MethodDeclaration);
-    }
-    if (enclosingElement is CompilationUnitElement) {
+    } else if (enclosingElement is CompilationUnitElement) {
       return getNodeMatching((node) => node is FunctionDeclaration);
     }
     return null;
   }
 }
 
 /**
  * A concrete implementation of a [PropertyInducingElement].
  */
 abstract class PropertyInducingElementImpl extends VariableElementImpl
@@ skipping 309 matching lines @@
 
   @override
   void visitElement(Element element) {
     int offset = element.nameOffset;
     if (offset != -1) {
       map[offset] = element;
     }
     super.visitElement(element);
   }
 }