Fix 56 hints in pkg/compiler

pkg/compiler/lib/src/typechecker.dart

 // Copyright (c) 2012, 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.
 
 part of dart2js;
 
 class TypeCheckerTask extends CompilerTask {
   TypeCheckerTask(Compiler compiler) : super(compiler);
   String get name => "Type checker";
 
@@ skipping 576 matching lines @@
   }
 
   DartType visitFunctionDeclaration(FunctionDeclaration node) {
     analyze(node.function);
     return const StatementType();
   }
 
   DartType visitFunctionExpression(FunctionExpression node) {
     DartType type;
     DartType returnType;
-    DartType previousType;
     final FunctionElement element = elements.getFunctionDefinition(node);
     assert(invariant(node, element != null,
                      message: 'FunctionExpression with no element'));
     if (Elements.isUnresolved(element)) return const DynamicType();
     if (element.isGenerativeConstructor) {
       type = const DynamicType();
       returnType = const VoidType();
 
       element.functionSignature.forEachParameter((ParameterElement parameter) {
         if (parameter.isInitializingFormal) {
@@ skipping 379 matching lines @@
           assert(invariant(node, element != null,
               message: 'Prefixed node has no element.'));
           return computeResolvedAccess(node, name, element, memberKind);
         }
       }
       // e.foo() for some expression e.
       DartType receiverType = analyze(node.receiver);
       if (receiverType.treatAsDynamic || receiverType.isVoid) {
         return const DynamicAccess();
       }
-      TypeKind receiverKind = receiverType.kind;
       return lookupMember(node, receiverType, name, memberKind,
           elements[node.receiver],
           lookupClassMember: lookupClassMember ||
               element != null && element.isStatic);
     } else {
       return computeResolvedAccess(node, name, element, memberKind);
     }
   }
 
   /**
@@ skipping 668 matching lines @@
         DartType initializer = analyzeNonVoid(initialization.arguments.head);
         checkAssignable(initialization.assignmentOperator, initializer, type);
       }
     }
     return const StatementType();
   }
 
   DartType visitWhile(While node) {
     checkCondition(node.condition);
     analyze(node.body);
-    Expression cond = node.condition.asParenthesizedExpression().expression;
     return const StatementType();
   }
 
   DartType visitParenthesizedExpression(ParenthesizedExpression node) {
     Expression expression = node.expression;
     DartType type = analyze(expression);
     for (TypePromotion typePromotion in getShownTypePromotionsFor(expression)) {
       showTypePromotion(node, typePromotion);
     }
     return type;
@@ skipping 161 matching lines @@
 
   visitTypedef(Typedef node) {
     // Do not typecheck [Typedef] nodes.
   }
 
   visitNode(Node node) {
     compiler.internalError(node,
         'Unexpected node ${node.getObjectDescription()} in the type checker.');
   }
 }