Implement _SameResolutionValidator as AstComparator.

pkg/analyzer/lib/src/generated/incremental_resolution_validator.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.generated.incremental_resolution_validator;
 
 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/utilities.dart';
 import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/member.dart';
 
 /**
  * Validates that the [actual] and the [expected] units have the same structure
  * and resolution. Throws [IncrementalResolutionMismatch] otherwise.
  */
 void assertSameResolution(CompilationUnit actual, CompilationUnit expected,
     {bool validateTypes: false}) {
-  _SameResolutionValidator validator =
-      new _SameResolutionValidator(validateTypes, expected);
-  actual.accept(validator);
+  _SameResolutionValidator validator = new _SameResolutionValidator(validateTypes);
+  validator.isEqualNodes(expected, actual);
 }
 
 /**
  * This exception is thrown when a mismatch between actual and expected AST
  * or resolution is found.
  */
 class IncrementalResolutionMismatch {
   final String message;
   IncrementalResolutionMismatch(this.message);
 
   @override
   String toString() => "IncrementalResolutionMismatch: $message";
 }
 
-class _SameResolutionValidator implements AstVisitor {
+/**
+ * An [AstVisitor] that compares the structure of two [AstNode]s and their
+ * resolution to see whether they are equal.
+ */
+class _SameResolutionValidator extends AstComparator {
   final bool validateTypes;
 
-  /// The expected node to compare with the visited node.
-  AstNode other;
-
-  _SameResolutionValidator(this.validateTypes, this.other);
+  _SameResolutionValidator(this.validateTypes);
 
   @override
-  visitAdjacentStrings(AdjacentStrings node) {}
-
-  @override
-  visitAnnotation(Annotation node) {
-    Annotation other = this.other;
-    _visitNode(node.name, other.name);
-    _visitNode(node.constructorName, other.constructorName);
-    _visitNode(node.arguments, other.arguments);
-    _verifyElement(node.element, other.element);
+  bool failDifferentLength(List expectedList, List actualList) {
+    int expectedLength = expectedList.length;
+    int actualLength = actualList.length;
+    String message = '';
+    message += 'Expected length: $expectedLength\n';
+    message += 'but $actualLength found\n';
+    message += 'in $actualList';
+    _fail(message);
+    return false;
   }
 
   @override
-  visitArgumentList(ArgumentList node) {
-    ArgumentList other = this.other;
-    _visitList(node.arguments, other.arguments);
+  bool failIfNotNull(Object expected, Object actual) {
+    if (actual != null) {
+      _fail('Expected null, but found $actual');
+      return false;
+    }
+    return true;
   }
 
   @override
-  visitAsExpression(AsExpression node) {
-    AsExpression other = this.other;
-    _visitExpression(node, other);
-    _visitNode(node.expression, other.expression);
-    _visitNode(node.type, other.type);
+  bool failIsNull(Object expected, Object actual) {
+    _fail('Expected not null, but found null');
+    return false;
   }
 
   @override
-  visitAssertStatement(AssertStatement node) {
-    AssertStatement other = this.other;
-    _visitNode(node.condition, other.condition);
-    _visitNode(node.message, other.message);
+  bool failRuntimeType(Object expected, Object actual) {
+    _fail('Expected ${expected.runtimeType}, but found ${actual.runtimeType}');
+    return false;
   }
 
   @override
-  visitAssignmentExpression(AssignmentExpression node) {
-    AssignmentExpression other = this.other;
-    _visitExpression(node, other);
-    _verifyElement(node.staticElement, other.staticElement);
-    _verifyElement(node.propagatedElement, other.propagatedElement);
-    _visitNode(node.leftHandSide, other.leftHandSide);
-    _visitNode(node.rightHandSide, other.rightHandSide);
+  bool isEqualNodes(AstNode first, AstNode second) {
+    super.isEqualNodes(first, second);
+    if (first is SimpleIdentifier && second is SimpleIdentifier) {
+      int offset = first.offset;
+      _verifyElement(
+          first.staticElement, second.staticElement, 'staticElement[$offset]');
+      _verifyElement(first.propagatedElement, second.propagatedElement,
+          'propagatedElement[$offset]');
+    } else if (first is Declaration && second is Declaration) {
+      int offset = first.offset;
+      _verifyElement(first.element, second.element, 'declaration[$offset]');
+    } else if (first is Directive && second is Directive) {
+      int offset = first.offset;
+      _verifyElement(first.element, second.element, 'directive[$offset]');
+    } else if (first is Expression && second is Expression) {
+      int offset = first.offset;
+      _verifyType(first.staticType, second.staticType, 'staticType[$offset]');
+      _verifyType(first.propagatedType, second.propagatedType,
+          'propagatedType[$offset]');
+      _verifyElement(first.staticParameterElement,
+          second.staticParameterElement, 'staticParameterElement[$offset]');
+      _verifyElement(
+          first.propagatedParameterElement,
+          second.propagatedParameterElement,
+          'propagatedParameterElement[$offset]');
+    }
+    return true;
   }
 
   @override
-  visitAwaitExpression(AwaitExpression node) {
-    AwaitExpression other = this.other;
-    _visitExpression(node, other);
-    _visitNode(node.expression, other.expression);
-  }
-
-  @override
-  visitBinaryExpression(BinaryExpression node) {
-    BinaryExpression other = this.other;
-    _visitExpression(node, other);
-    _verifyElement(node.staticElement, other.staticElement);
-    _verifyElement(node.propagatedElement, other.propagatedElement);
-    _visitNode(node.leftOperand, other.leftOperand);
-    _visitNode(node.rightOperand, other.rightOperand);
-  }
-
-  @override
-  visitBlock(Block node) {
-    Block other = this.other;
-    _visitList(node.statements, other.statements);
-  }
-
-  @override
-  visitBlockFunctionBody(BlockFunctionBody node) {
-    BlockFunctionBody other = this.other;
-    _visitNode(node.block, other.block);
-  }
-
-  @override
-  visitBooleanLiteral(BooleanLiteral node) {
-    BooleanLiteral other = this.other;
-    _visitExpression(node, other);
-  }
-
-  @override
-  visitBreakStatement(BreakStatement node) {
-    BreakStatement other = this.other;
-    _visitNode(node.label, other.label);
-  }
-
-  @override
-  visitCascadeExpression(CascadeExpression node) {
-    CascadeExpression other = this.other;
-    _visitExpression(node, other);
-    _visitNode(node.target, other.target);
-    _visitList(node.cascadeSections, other.cascadeSections);
-  }
-
-  @override
-  visitCatchClause(CatchClause node) {
-    CatchClause other = this.other;
-    _visitNode(node.exceptionType, other.exceptionType);
-    _visitNode(node.exceptionParameter, other.exceptionParameter);
-    _visitNode(node.stackTraceParameter, other.stackTraceParameter);
-    _visitNode(node.body, other.body);
-  }
-
-  @override
-  visitClassDeclaration(ClassDeclaration node) {
-    ClassDeclaration other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.name, other.name);
-    _visitNode(node.typeParameters, other.typeParameters);
-    _visitNode(node.extendsClause, other.extendsClause);
-    _visitNode(node.implementsClause, other.implementsClause);
-    _visitNode(node.withClause, other.withClause);
-    _visitList(node.members, other.members);
-  }
-
-  @override
-  visitClassTypeAlias(ClassTypeAlias node) {
-    ClassTypeAlias other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.name, other.name);
-    _visitNode(node.typeParameters, other.typeParameters);
-    _visitNode(node.superclass, other.superclass);
-    _visitNode(node.withClause, other.withClause);
-  }
-
-  @override
-  visitComment(Comment node) {
-    Comment other = this.other;
-    _visitList(node.references, other.references);
-  }
-
-  @override
-  visitCommentReference(CommentReference node) {
-    CommentReference other = this.other;
-    _visitNode(node.identifier, other.identifier);
-  }
-
-  @override
-  visitCompilationUnit(CompilationUnit node) {
-    CompilationUnit other = this.other;
-    _verifyElement(node.element, other.element);
-    _visitList(node.directives, other.directives);
-    _visitList(node.declarations, other.declarations);
-  }
-
-  @override
-  visitConditionalExpression(ConditionalExpression node) {
-    ConditionalExpression other = this.other;
-    _visitExpression(node, other);
-    _visitNode(node.condition, other.condition);
-    _visitNode(node.thenExpression, other.thenExpression);
-    _visitNode(node.elseExpression, other.elseExpression);
-  }
-
-  @override
-  visitConfiguration(Configuration node) {
-    Configuration other = this.other;
-    _visitNode(node.name, other.name);
-    _visitNode(node.value, other.value);
-    _visitNode(node.libraryUri, other.libraryUri);
-  }
-
-  @override
-  visitConstructorDeclaration(ConstructorDeclaration node) {
-    ConstructorDeclaration other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.returnType, other.returnType);
-    _visitNode(node.name, other.name);
-    _visitNode(node.parameters, other.parameters);
-    _visitNode(node.redirectedConstructor, other.redirectedConstructor);
-    _visitList(node.initializers, other.initializers);
-  }
-
-  @override
-  visitConstructorFieldInitializer(ConstructorFieldInitializer node) {
-    ConstructorFieldInitializer other = this.other;
-    _visitNode(node.fieldName, other.fieldName);
-    _visitNode(node.expression, other.expression);
-  }
-
-  @override
-  visitConstructorName(ConstructorName node) {
-    ConstructorName other = this.other;
-    _verifyElement(node.staticElement, other.staticElement);
-    _visitNode(node.type, other.type);
-    _visitNode(node.name, other.name);
-  }
-
-  @override
-  visitContinueStatement(ContinueStatement node) {
-    ContinueStatement other = this.other;
-    _visitNode(node.label, other.label);
-  }
-
-  @override
-  visitDeclaredIdentifier(DeclaredIdentifier node) {
-    DeclaredIdentifier other = this.other;
-    _visitNode(node.type, other.type);
-    _visitNode(node.identifier, other.identifier);
-  }
-
-  @override
-  visitDefaultFormalParameter(DefaultFormalParameter node) {
-    DefaultFormalParameter other = this.other;
-    _visitNode(node.parameter, other.parameter);
-    _visitNode(node.defaultValue, other.defaultValue);
-  }
-
-  @override
-  visitDoStatement(DoStatement node) {
-    DoStatement other = this.other;
-    _visitNode(node.condition, other.condition);
-    _visitNode(node.body, other.body);
-  }
-
-  @override
-  visitDottedName(DottedName node) {
-    DottedName other = this.other;
-    _visitList(node.components, other.components);
-  }
-
-  @override
-  visitDoubleLiteral(DoubleLiteral node) {
-    DoubleLiteral other = this.other;
-    _visitExpression(node, other);
-  }
-
-  @override
-  visitEmptyFunctionBody(EmptyFunctionBody node) {}
-
-  @override
-  visitEmptyStatement(EmptyStatement node) {}
-
-  @override
-  visitEnumConstantDeclaration(EnumConstantDeclaration node) {
-    EnumConstantDeclaration other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.name, other.name);
-  }
-
-  @override
-  visitEnumDeclaration(EnumDeclaration node) {
-    EnumDeclaration other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.name, other.name);
-    _visitList(node.constants, other.constants);
-  }
-
-  @override
-  visitExportDirective(ExportDirective node) {
-    ExportDirective other = this.other;
-    _visitDirective(node, other);
-  }
-
-  @override
-  visitExpressionFunctionBody(ExpressionFunctionBody node) {
-    ExpressionFunctionBody other = this.other;
-    _visitNode(node.expression, other.expression);
-  }
-
-  @override
-  visitExpressionStatement(ExpressionStatement node) {
-    ExpressionStatement other = this.other;
-    _visitNode(node.expression, other.expression);
-  }
-
-  @override
-  visitExtendsClause(ExtendsClause node) {
-    ExtendsClause other = this.other;
-    _visitNode(node.superclass, other.superclass);
-  }
-
-  @override
-  visitFieldDeclaration(FieldDeclaration node) {
-    FieldDeclaration other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.fields, other.fields);
-  }
-
-  @override
-  visitFieldFormalParameter(FieldFormalParameter node) {
-    FieldFormalParameter other = this.other;
-    _visitNormalFormalParameter(node, other);
-    _visitNode(node.type, other.type);
-    _visitNode(node.parameters, other.parameters);
-  }
-
-  @override
-  visitForEachStatement(ForEachStatement node) {
-    ForEachStatement other = this.other;
-    _visitNode(node.identifier, other.identifier);
-    _visitNode(node.loopVariable, other.loopVariable);
-    _visitNode(node.iterable, other.iterable);
-  }
-
-  @override
-  visitFormalParameterList(FormalParameterList node) {
-    FormalParameterList other = this.other;
-    _visitList(node.parameters, other.parameters);
-  }
-
-  @override
-  visitForStatement(ForStatement node) {
-    ForStatement other = this.other;
-    _visitNode(node.variables, other.variables);
-    _visitNode(node.initialization, other.initialization);
-    _visitNode(node.condition, other.condition);
-    _visitList(node.updaters, other.updaters);
-    _visitNode(node.body, other.body);
-  }
-
-  @override
-  visitFunctionDeclaration(FunctionDeclaration node) {
-    FunctionDeclaration other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.returnType, other.returnType);
-    _visitNode(node.name, other.name);
-    _visitNode(node.functionExpression, other.functionExpression);
-  }
-
-  @override
-  visitFunctionDeclarationStatement(FunctionDeclarationStatement node) {
-    FunctionDeclarationStatement other = this.other;
-    _visitNode(node.functionDeclaration, other.functionDeclaration);
-  }
-
-  @override
-  visitFunctionExpression(FunctionExpression node) {
-    FunctionExpression other = this.other;
-    _visitExpression(node, other);
-    _verifyElement(node.element, other.element);
-    _visitNode(node.parameters, other.parameters);
-    _visitNode(node.body, other.body);
-  }
-
-  @override
-  visitFunctionExpressionInvocation(FunctionExpressionInvocation node) {
-    FunctionExpressionInvocation other = this.other;
-    _visitExpression(node, other);
-    _verifyElement(node.staticElement, other.staticElement);
-    _verifyElement(node.propagatedElement, other.propagatedElement);
-    _visitNode(node.function, other.function);
-    _visitNode(node.argumentList, other.argumentList);
-  }
-
-  @override
-  visitFunctionTypeAlias(FunctionTypeAlias node) {
-    FunctionTypeAlias other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.returnType, other.returnType);
-    _visitNode(node.name, other.name);
-    _visitNode(node.typeParameters, other.typeParameters);
-    _visitNode(node.parameters, other.parameters);
-  }
-
-  @override
-  visitFunctionTypedFormalParameter(FunctionTypedFormalParameter node) {
-    FunctionTypedFormalParameter other = this.other;
-    _visitNormalFormalParameter(node, other);
-    _visitNode(node.returnType, other.returnType);
-    _visitNode(node.parameters, other.parameters);
-  }
-
-  @override
-  visitHideCombinator(HideCombinator node) {
-    HideCombinator other = this.other;
-    _visitList(node.hiddenNames, other.hiddenNames);
-  }
-
-  @override
-  visitIfStatement(IfStatement node) {
-    IfStatement other = this.other;
-    _visitNode(node.condition, other.condition);
-    _visitNode(node.thenStatement, other.thenStatement);
-    _visitNode(node.elseStatement, other.elseStatement);
-  }
-
-  @override
-  visitImplementsClause(ImplementsClause node) {
-    ImplementsClause other = this.other;
-    _visitList(node.interfaces, other.interfaces);
-  }
-
-  @override
-  visitImportDirective(ImportDirective node) {
-    ImportDirective other = this.other;
-    _visitDirective(node, other);
-    _visitNode(node.prefix, other.prefix);
-    _verifyElement(node.uriElement, other.uriElement);
-  }
-
-  @override
-  visitIndexExpression(IndexExpression node) {
-    IndexExpression other = this.other;
-    _visitExpression(node, other);
-    _verifyElement(node.staticElement, other.staticElement);
-    _verifyElement(node.propagatedElement, other.propagatedElement);
-    _visitNode(node.target, other.target);
-    _visitNode(node.index, other.index);
-  }
-
-  @override
-  visitInstanceCreationExpression(InstanceCreationExpression node) {
-    InstanceCreationExpression other = this.other;
-    _visitExpression(node, other);
-    _verifyElement(node.staticElement, other.staticElement);
-    _visitNode(node.constructorName, other.constructorName);
-    _visitNode(node.argumentList, other.argumentList);
-  }
-
-  @override
-  visitIntegerLiteral(IntegerLiteral node) {
-    IntegerLiteral other = this.other;
-    _visitExpression(node, other);
-  }
-
-  @override
-  visitInterpolationExpression(InterpolationExpression node) {
-    InterpolationExpression other = this.other;
-    _visitNode(node.expression, other.expression);
-  }
-
-  @override
-  visitInterpolationString(InterpolationString node) {}
-
-  @override
-  visitIsExpression(IsExpression node) {
-    IsExpression other = this.other;
-    _visitExpression(node, other);
-    _visitNode(node.expression, other.expression);
-    _visitNode(node.type, other.type);
-  }
-
-  @override
-  visitLabel(Label node) {
-    Label other = this.other;
-    _visitNode(node.label, other.label);
-  }
-
-  @override
-  visitLabeledStatement(LabeledStatement node) {
-    LabeledStatement other = this.other;
-    _visitList(node.labels, other.labels);
-    _visitNode(node.statement, other.statement);
-  }
-
-  @override
-  visitLibraryDirective(LibraryDirective node) {
-    LibraryDirective other = this.other;
-    _visitDirective(node, other);
-    _visitNode(node.name, other.name);
-  }
-
-  @override
-  visitLibraryIdentifier(LibraryIdentifier node) {
-    LibraryIdentifier other = this.other;
-    _visitList(node.components, other.components);
-  }
-
-  @override
-  visitListLiteral(ListLiteral node) {
-    ListLiteral other = this.other;
-    _visitExpression(node, other);
-    _visitList(node.elements, other.elements);
-  }
-
-  @override
-  visitMapLiteral(MapLiteral node) {
-    MapLiteral other = this.other;
-    _visitExpression(node, other);
-    _visitList(node.entries, other.entries);
-  }
-
-  @override
-  visitMapLiteralEntry(MapLiteralEntry node) {
-    MapLiteralEntry other = this.other;
-    _visitNode(node.key, other.key);
-    _visitNode(node.value, other.value);
-  }
-
-  @override
-  visitMethodDeclaration(MethodDeclaration node) {
-    MethodDeclaration other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.name, other.name);
-    _visitNode(node.parameters, other.parameters);
-    _visitNode(node.body, other.body);
-  }
-
-  @override
-  visitMethodInvocation(MethodInvocation node) {
-    MethodInvocation other = this.other;
-    _visitNode(node.target, other.target);
-    _visitNode(node.methodName, other.methodName);
-    _visitNode(node.argumentList, other.argumentList);
-  }
-
-  @override
-  visitNamedExpression(NamedExpression node) {
-    NamedExpression other = this.other;
-    _visitNode(node.name, other.name);
-    _visitNode(node.expression, other.expression);
-  }
-
-  @override
-  visitNativeClause(NativeClause node) {}
-
-  @override
-  visitNativeFunctionBody(NativeFunctionBody node) {}
-
-  @override
-  visitNullLiteral(NullLiteral node) {
-    NullLiteral other = this.other;
-    _visitExpression(node, other);
-  }
-
-  @override
-  visitParenthesizedExpression(ParenthesizedExpression node) {
-    ParenthesizedExpression other = this.other;
-    _visitNode(node.expression, other.expression);
-  }
-
-  @override
-  visitPartDirective(PartDirective node) {
-    PartDirective other = this.other;
-    _visitDirective(node, other);
-  }
-
-  @override
-  visitPartOfDirective(PartOfDirective node) {
-    PartOfDirective other = this.other;
-    _visitDirective(node, other);
-    _visitNode(node.libraryName, other.libraryName);
-  }
-
-  @override
-  visitPostfixExpression(PostfixExpression node) {
-    PostfixExpression other = this.other;
-    _visitExpression(node, other);
-    _verifyElement(node.staticElement, other.staticElement);
-    _verifyElement(node.propagatedElement, other.propagatedElement);
-    _visitNode(node.operand, other.operand);
-  }
-
-  @override
-  visitPrefixedIdentifier(PrefixedIdentifier node) {
-    PrefixedIdentifier other = this.other;
-    _visitExpression(node, other);
-    _visitNode(node.prefix, other.prefix);
-    _visitNode(node.identifier, other.identifier);
-  }
-
-  @override
-  visitPrefixExpression(PrefixExpression node) {
-    PrefixExpression other = this.other;
-    _visitExpression(node, other);
-    _verifyElement(node.staticElement, other.staticElement);
-    _verifyElement(node.propagatedElement, other.propagatedElement);
-    _visitNode(node.operand, other.operand);
-  }
-
-  @override
-  visitPropertyAccess(PropertyAccess node) {
-    PropertyAccess other = this.other;
-    _visitExpression(node, other);
-    _visitNode(node.target, other.target);
-    _visitNode(node.propertyName, other.propertyName);
-  }
-
-  @override
-  visitRedirectingConstructorInvocation(RedirectingConstructorInvocation node) {
-    RedirectingConstructorInvocation other = this.other;
-    _verifyElement(node.staticElement, other.staticElement);
-    _visitNode(node.constructorName, other.constructorName);
-    _visitNode(node.argumentList, other.argumentList);
-  }
-
-  @override
-  visitRethrowExpression(RethrowExpression node) {
-    RethrowExpression other = this.other;
-    _visitExpression(node, other);
-  }
-
-  @override
-  visitReturnStatement(ReturnStatement node) {
-    ReturnStatement other = this.other;
-    _visitNode(node.expression, other.expression);
-  }
-
-  @override
-  visitScriptTag(ScriptTag node) {}
-
-  @override
-  visitShowCombinator(ShowCombinator node) {
-    ShowCombinator other = this.other;
-    _visitList(node.shownNames, other.shownNames);
-  }
-
-  @override
-  visitSimpleFormalParameter(SimpleFormalParameter node) {
-    SimpleFormalParameter other = this.other;
-    _visitNormalFormalParameter(node, other);
-    _visitNode(node.type, other.type);
-  }
-
-  @override
-  visitSimpleIdentifier(SimpleIdentifier node) {
-    SimpleIdentifier other = this.other;
-    _verifyElement(node.staticElement, other.staticElement);
-    _verifyElement(node.propagatedElement, other.propagatedElement);
-    _visitExpression(node, other);
-  }
-
-  @override
-  visitSimpleStringLiteral(SimpleStringLiteral node) {}
-
-  @override
-  visitStringInterpolation(StringInterpolation node) {
-    StringInterpolation other = this.other;
-    _visitList(node.elements, other.elements);
-  }
-
-  @override
-  visitSuperConstructorInvocation(SuperConstructorInvocation node) {
-    SuperConstructorInvocation other = this.other;
-    _verifyElement(node.staticElement, other.staticElement);
-    _visitNode(node.constructorName, other.constructorName);
-    _visitNode(node.argumentList, other.argumentList);
-  }
-
-  @override
-  visitSuperExpression(SuperExpression node) {
-    SuperExpression other = this.other;
-    _visitExpression(node, other);
-  }
-
-  @override
-  visitSwitchCase(SwitchCase node) {
-    SwitchCase other = this.other;
-    _visitList(node.labels, other.labels);
-    _visitNode(node.expression, other.expression);
-    _visitList(node.statements, other.statements);
-  }
-
-  @override
-  visitSwitchDefault(SwitchDefault node) {
-    SwitchDefault other = this.other;
-    _visitList(node.statements, other.statements);
-  }
-
-  @override
-  visitSwitchStatement(SwitchStatement node) {
-    SwitchStatement other = this.other;
-    _visitNode(node.expression, other.expression);
-    _visitList(node.members, other.members);
-  }
-
-  @override
-  visitSymbolLiteral(SymbolLiteral node) {}
-
-  @override
-  visitThisExpression(ThisExpression node) {
-    ThisExpression other = this.other;
-    _visitExpression(node, other);
-  }
-
-  @override
-  visitThrowExpression(ThrowExpression node) {
-    ThrowExpression other = this.other;
-    _visitNode(node.expression, other.expression);
-  }
-
-  @override
-  visitTopLevelVariableDeclaration(TopLevelVariableDeclaration node) {
-    TopLevelVariableDeclaration other = this.other;
-    _visitNode(node.variables, other.variables);
-  }
-
-  @override
-  visitTryStatement(TryStatement node) {
-    TryStatement other = this.other;
-    _visitNode(node.body, other.body);
-    _visitList(node.catchClauses, other.catchClauses);
-    _visitNode(node.finallyBlock, other.finallyBlock);
-  }
-
-  @override
-  visitTypeArgumentList(TypeArgumentList node) {
-    TypeArgumentList other = this.other;
-    _visitList(node.arguments, other.arguments);
-  }
-
-  @override
-  visitTypeName(TypeName node) {
-    TypeName other = this.other;
-    _verifyType(node.type, other.type);
-    _visitNode(node.name, node.name);
-    _visitNode(node.typeArguments, other.typeArguments);
-  }
-
-  @override
-  visitTypeParameter(TypeParameter node) {
-    TypeParameter other = this.other;
-    _visitNode(node.name, other.name);
-    _visitNode(node.bound, other.bound);
-  }
-
-  @override
-  visitTypeParameterList(TypeParameterList node) {
-    TypeParameterList other = this.other;
-    _visitList(node.typeParameters, other.typeParameters);
-  }
-
-  @override
-  visitVariableDeclaration(VariableDeclaration node) {
-    VariableDeclaration other = this.other;
-    _visitDeclaration(node, other);
-    _visitNode(node.name, other.name);
-    _visitNode(node.initializer, other.initializer);
-  }
-
-  @override
-  visitVariableDeclarationList(VariableDeclarationList node) {
-    VariableDeclarationList other = this.other;
-    _visitNode(node.type, other.type);
-    _visitList(node.variables, other.variables);
-  }
-
-  @override
-  visitVariableDeclarationStatement(VariableDeclarationStatement node) {
-    VariableDeclarationStatement other = this.other;
-    _visitNode(node.variables, other.variables);
-  }
-
-  @override
-  visitWhileStatement(WhileStatement node) {
-    WhileStatement other = this.other;
-    _visitNode(node.condition, other.condition);
-    _visitNode(node.body, other.body);
-  }
-
-  @override
-  visitWithClause(WithClause node) {
-    WithClause other = this.other;
-    _visitList(node.mixinTypes, other.mixinTypes);
-  }
-
-  @override
-  visitYieldStatement(YieldStatement node) {
-    YieldStatement other = this.other;
-    _visitNode(node.expression, other.expression);
-  }
-
-  void _assertNode(AstNode a, AstNode b) {
-    _expectEquals(a.offset, b.offset);
-    _expectEquals(a.length, b.length);
-  }
-
-  void _expectEquals(actual, expected) {
-    if (actual != expected) {
-      String message = '';
-      message += 'Expected: $expected\n';
-      message += '  Actual: $actual\n';
-      _fail(message);
-    }
-  }
-
-  void _expectIsNull(obj) {
-    if (obj != null) {
-      String message = '';
-      message += 'Expected: null\n';
-      message += '  Actual: $obj\n';
-      _fail(message);
-    }
-  }
-
-  void _expectLength(List actualList, int expected) {
-    String message = '';
-    message += 'Expected length: $expected\n';
-    if (actualList == null) {
-      message += 'but null found.';
-      _fail(message);
-    }
-    int actual = actualList.length;
-    if (actual != expected) {
-      message += 'but $actual found\n';
-      message += 'in $actualList';
-      _fail(message);
-    }
+  bool isEqualTokensNotNull(Token expected, Token actual) {
+    _verifyEqual('lexeme', expected.lexeme, actual.lexeme);
+    _verifyEqual('offset', expected.offset, actual.offset);
+    _verifyEqual('offset', expected.length, actual.length);
+    return true;
   }
 
   void _fail(String message) {
     throw new IncrementalResolutionMismatch(message);
   }
 
-  void _verifyElement(Element a, Element b) {
+  void _verifyElement(Element a, Element b, String desc) {
     if (a is Member && b is Member) {
       a = (a as Member).baseElement;
       b = (b as Member).baseElement;
     }
     String locationA = _getElementLocationWithoutUri(a);
     String locationB = _getElementLocationWithoutUri(b);
     if (locationA != locationB) {
-      int offset = other.offset;
-      _fail('[$offset]\nExpected: $b ($locationB)\n  Actual: $a ($locationA)');
+      _fail('$desc\nExpected: $b ($locationB)\n  Actual: $a ($locationA)');
     }
     if (a == null && b == null) {
       return;
     }
     _verifyEqual('nameOffset', a.nameOffset, b.nameOffset);
     if (a is ElementImpl && b is ElementImpl) {
       _verifyEqual('codeOffset', a.codeOffset, b.codeOffset);
       _verifyEqual('codeLength', a.codeLength, b.codeLength);
     }
     if (a is LocalElement && b is LocalElement) {
       _verifyEqual('visibleRange', a.visibleRange, b.visibleRange);
     }
     _verifyEqual(
         'documentationComment', a.documentationComment, b.documentationComment);
   }
 
   void _verifyEqual(String name, actual, expected) {
     if (actual != expected) {
       _fail('$name\nExpected: $expected\n  Actual: $actual');
     }
   }
 
-  void _verifyType(DartType a, DartType b) {
+  void _verifyType(DartType a, DartType b, String desc) {
     if (!validateTypes) {
       return;
     }
     if (a != b) {
-      int offset = other.offset;
-      _fail('[$offset]\nExpected: $b\n  Actual: $a');
+      _fail('$desc\nExpected: $b\n  Actual: $a');
     }
   }
 
-  void _visitAnnotatedNode(AnnotatedNode node, AnnotatedNode other) {
-    _visitNode(node.documentationComment, other.documentationComment);
-    _visitList(node.metadata, other.metadata);
-  }
-
-  _visitDeclaration(Declaration node, Declaration other) {
-    _verifyElement(node.element, other.element);
-    _visitAnnotatedNode(node, other);
-  }
-
-  _visitDirective(Directive node, Directive other) {
-    _verifyElement(node.element, other.element);
-    _visitAnnotatedNode(node, other);
-  }
-
-  void _visitExpression(Expression a, Expression b) {
-//    print('[${a.offset}] |$a| vs. [${b.offset}] |$b|');
-    _verifyType(a.staticType, b.staticType);
-    _verifyType(a.propagatedType, b.propagatedType);
-    _verifyElement(a.staticParameterElement, b.staticParameterElement);
-    _verifyElement(a.propagatedParameterElement, b.propagatedParameterElement);
-    _assertNode(a, b);
-  }
-
-  void _visitList(NodeList nodeList, NodeList expected) {
-    int length = nodeList.length;
-    _expectLength(nodeList, expected.length);
-    for (int i = 0; i < length; i++) {
-      _visitNode(nodeList[i], expected[i]);
-    }
-  }
-
-  void _visitNode(AstNode node, AstNode other) {
-    if (node == null) {
-      _expectIsNull(other);
-    } else {
-      this.other = other;
-      _assertNode(node, other);
-      node.accept(this);
-    }
-  }
-
-  void _visitNormalFormalParameter(
-      NormalFormalParameter node, NormalFormalParameter other) {
-    _verifyElement(node.element, other.element);
-    _visitNode(node.documentationComment, other.documentationComment);
-    _visitList(node.metadata, other.metadata);
-    _visitNode(node.identifier, other.identifier);
-  }
-
   /**
    * Returns an URI scheme independent version of the [element] location.
    */
   static String _getElementLocationWithoutUri(Element element) {
     if (element == null) {
       return '<null>';
     }
     if (element is UriReferencedElementImpl) {
       return '<ignored>';
     }
@@ skipping 26 matching lines @@
    *     package:project/my_lib.dart      -> my_lib.dart
    */
   static String _getShortElementLocationUri(String uri) {
     int index = uri.lastIndexOf('/');
     if (index == -1) {
       return uri;
     }
     return uri.substring(index + 1);
   }
 }