Move dart2js from sdk/lib/_internal/compiler to pkg/compiler

sdk/lib/_internal/compiler/implementation/elements/elements.dart

Index: sdk/lib/_internal/compiler/implementation/elements/elements.dart
diff --git a/sdk/lib/_internal/compiler/implementation/elements/elements.dart b/sdk/lib/_internal/compiler/implementation/elements/elements.dart
deleted file mode 100644
index 442e12b22701773a76c374dde646b3d4dcc2f264..0000000000000000000000000000000000000000
--- a/sdk/lib/_internal/compiler/implementation/elements/elements.dart
+++ /dev/null
@@ -1,1611 +0,0 @@
-// 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.
-
-library elements;
-
-
-import '../constants/expressions.dart';
-import '../tree/tree.dart';
-import '../util/util.dart';
-import '../resolution/resolution.dart';
-
-import '../dart2jslib.dart' show InterfaceType,
-                                 DartType,
-                                 TypeVariableType,
-                                 TypedefType,
-                                 DualKind,
-                                 MessageKind,
-                                 DiagnosticListener,
-                                 Script,
-                                 FunctionType,
-                                 Selector,
-                                 Constant,
-                                 Compiler,
-                                 Backend,
-                                 isPrivateName;
-
-import '../dart_types.dart';
-import '../helpers/helpers.dart';
-
-import '../scanner/scannerlib.dart' show Token,
-                                         isUserDefinableOperator,
-                                         isMinusOperator;
-
-import '../ordered_typeset.dart' show OrderedTypeSet;
-
-import 'visitor.dart' show ElementVisitor;
-
-part 'names.dart';
-
-const int STATE_NOT_STARTED = 0;
-const int STATE_STARTED = 1;
-const int STATE_DONE = 2;
-
-class ElementCategory {
-  /**
-   * Represents things that we don't expect to find when looking in a
-   * scope.
-   */
-  static const int NONE = 0;
-
-  /** Field, parameter, or variable. */
-  static const int VARIABLE = 1;
-
-  /** Function, method, or foreign function. */
-  static const int FUNCTION = 2;
-
-  static const int CLASS = 4;
-
-  static const int PREFIX = 8;
-
-  /** Constructor or factory. */
-  static const int FACTORY = 16;
-
-  static const int ALIAS = 32;
-
-  static const int SUPER = 64;
-
-  /** Type variable */
-  static const int TYPE_VARIABLE = 128;
-
-  static const int IMPLIES_TYPE = CLASS | ALIAS | TYPE_VARIABLE;
-}
-
-class ElementKind {
-  final String id;
-  final int category;
-
-  const ElementKind(String this.id, this.category);
-
-  static const ElementKind VARIABLE =
-      const ElementKind('variable', ElementCategory.VARIABLE);
-  static const ElementKind PARAMETER =
-      const ElementKind('parameter', ElementCategory.VARIABLE);
-  // Parameters in constructors that directly initialize fields. For example:
-  // [:A(this.field):].
-  static const ElementKind INITIALIZING_FORMAL =
-      const ElementKind('initializing_formal', ElementCategory.VARIABLE);
-  static const ElementKind FUNCTION =
-      const ElementKind('function', ElementCategory.FUNCTION);
-  static const ElementKind CLASS =
-      const ElementKind('class', ElementCategory.CLASS);
-  static const ElementKind GENERATIVE_CONSTRUCTOR =
-      const ElementKind('generative_constructor', ElementCategory.FACTORY);
-  static const ElementKind FIELD =
-      const ElementKind('field', ElementCategory.VARIABLE);
-  static const ElementKind FIELD_LIST =
-      const ElementKind('field_list', ElementCategory.NONE);
-  static const ElementKind GENERATIVE_CONSTRUCTOR_BODY =
-      const ElementKind('generative_constructor_body', ElementCategory.NONE);
-  static const ElementKind COMPILATION_UNIT =
-      const ElementKind('compilation_unit', ElementCategory.NONE);
-  static const ElementKind GETTER =
-      const ElementKind('getter', ElementCategory.NONE);
-  static const ElementKind SETTER =
-      const ElementKind('setter', ElementCategory.NONE);
-  static const ElementKind TYPE_VARIABLE =
-      const ElementKind('type_variable', ElementCategory.TYPE_VARIABLE);
-  static const ElementKind ABSTRACT_FIELD =
-      const ElementKind('abstract_field', ElementCategory.VARIABLE);
-  static const ElementKind LIBRARY =
-      const ElementKind('library', ElementCategory.NONE);
-  static const ElementKind PREFIX =
-      const ElementKind('prefix', ElementCategory.PREFIX);
-  static const ElementKind TYPEDEF =
-      const ElementKind('typedef', ElementCategory.ALIAS);
-
-  static const ElementKind AMBIGUOUS =
-      const ElementKind('ambiguous', ElementCategory.NONE);
-  static const ElementKind WARN_ON_USE =
-      const ElementKind('warn_on_use', ElementCategory.NONE);
-  static const ElementKind ERROR =
-      const ElementKind('error', ElementCategory.NONE);
-
-  toString() => id;
-}
-
-/// Abstract interface for entities.
-///
-/// Implement this directly if the entity is not a Dart language entity.
-/// Entities defined within the Dart language should implement [Element].
-///
-/// For instance, the JavaScript backend need to create synthetic variables for
-/// calling intercepted classes and such variables do not correspond to an
-/// entity in the Dart source code nor in the terminology of the Dart language
-/// and should therefore implement [Entity] directly.
-abstract class Entity implements Spannable {
-  String get name;
-}
-
-/**
- * A declared element of a program.
- *
- * The declared elements of a program include classes, methods,
- * fields, variables, parameters, etc.
- *
- * Sometimes it makes sense to construct "synthetic" elements that
- * have not been declared anywhere in a program, for example, there
- * are elements corresponding to "dynamic", "null", and unresolved
- * references.
- *
- * Elements are distinct from types ([DartType]). For example, there
- * is one declaration of the class List, but several related types,
- * for example, List, List<int>, List<String>, etc.
- *
- * Elements are distinct from AST nodes ([Node]), and there normally is a
- * one-to-one correspondence between an AST node and an element
- * (except that not all kinds of AST nodes have an associated
- * element).
- *
- * AST nodes represent precisely what is written in source code, for
- * example, when a user writes "class MyClass {}", the corresponding
- * AST node does not have a superclass. On the other hand, the
- * corresponding element (once fully resolved) will record the
- * information about the implicit superclass as defined by the
- * language semantics.
- *
- * Generally, the contents of a method are represented as AST nodes
- * without additional elements, but things like local functions, local
- * variables, and labels have a corresponding element.
- *
- * We generally say that scanning, parsing, resolution, and type
- * checking comprise the "front-end" of the compiler. The "back-end"
- * includes things like SSA graph construction, optimizations, and
- * code generation.
- *
- * The front-end data structures are designed to be reusable by
- * several back-ends.  For example, we may want to support emitting
- * minified Dart and JavaScript code in one go.  Also, we're planning
- * on adding an incremental compilation server that should be able to
- * reuse elements between compilations.  So to keep things simple, it
- * is best if the backends avoid setting state directly in elements.
- * It is better to keep such state in a table on the side.
- */
-abstract class Element implements Entity {
-  String get name;
-  ElementKind get kind;
-  Element get enclosingElement;
-  Link<MetadataAnnotation> get metadata;
-
-  /// Do not use [computeType] outside of the resolver; instead retrieve the
-  /// type from the corresponding field:
-  /// - `type` for fields, variables, type variable, and function elements.
-  /// - `thisType` or `rawType` for [TypeDeclarationElement]s (classes and
-  ///    typedefs), depending on the use case.
-  /// Trying to access a type that has not been computed in resolution is an
-  /// error and calling [computeType] covers that error.
-  /// This method will go away!
-  @deprecated DartType computeType(Compiler compiler);
-
-  /// `true` if this element is a library.
-  bool get isLibrary => kind == ElementKind.LIBRARY;
-
-  /// `true` if this element is a compilation unit.
-  bool get isCompilationUnit => kind == ElementKind.COMPILATION_UNIT;
-
-  /// `true` if this element is defines the scope of prefix used by one or
-  /// more import declarations.
-  bool get isPrefix => kind == ElementKind.PREFIX;
-
-  /// `true` if this element is a class declaration or a mixin application.
-  bool get isClass => kind == ElementKind.CLASS;
-
-  /// `true` if this element is a type variable declaration.
-  bool get isTypeVariable => kind == ElementKind.TYPE_VARIABLE;
-
-  /// `true` if this element is a typedef declaration.
-  bool get isTypedef => kind == ElementKind.TYPEDEF;
-
-  /// `true` if this element is a top level function, static or instance
-  /// method, local function or closure defined by a function expression.
-  ///
-  /// This property is `true` for operator methods and factory constructors but
-  /// `false` for getter and setter methods, and generative constructors.
-  ///
-  /// See also [isConstructor], [isGenerativeConstructor], and
-  /// [isFactoryConstructor] for constructor properties, and [isAccessor],
-  /// [isGetter] and [isSetter] for getter/setter properties.
-  bool get isFunction => kind == ElementKind.FUNCTION;
-
-  /// `true` if this element is an operator method.
-  bool get isOperator;
-
-  /// `true` if this element is an accessor, that is either an explicit
-  /// getter or an explicit setter.
-  bool get isAccessor => isGetter || isSetter;
-
-  /// `true` if this element is an explicit getter method.
-  bool get isGetter => kind == ElementKind.GETTER;
-
-  /// `true` if this element is an explicit setter method.
-  bool get isSetter => kind == ElementKind.SETTER;
-
-  /// `true` if this element is a generative or factory constructor.
-  bool get isConstructor => isGenerativeConstructor ||  isFactoryConstructor;
-
-  /// `true` if this element is a generative constructor, potentially
-  /// redirecting.
-  bool get isGenerativeConstructor =>
-      kind == ElementKind.GENERATIVE_CONSTRUCTOR;
-
-  /// `true` if this element is the body of a generative constructor.
-  ///
-  /// This is a synthetic element kind used only be the JavaScript backend.
-  bool get isGenerativeConstructorBody =>
-      kind == ElementKind.GENERATIVE_CONSTRUCTOR_BODY;
-
-  /// `true` if this element is a factory constructor,
-  /// potentially redirecting.
-  bool get isFactoryConstructor;
-
-  /// `true` if this element is a local variable.
-  bool get isVariable => kind == ElementKind.VARIABLE;
-
-  /// `true` if this element is a top level variable, static or instance field.
-  bool get isField => kind == ElementKind.FIELD;
-
-  /// `true` if this element is the abstract field implicitly defined by an
-  /// explicit getter and/or setter.
-  bool get isAbstractField => kind == ElementKind.ABSTRACT_FIELD;
-
-  /// `true` if this element is formal parameter either from a constructor,
-  /// method, or typedef declaration or from an inlined function typed
-  /// parameter.
-  ///
-  /// This property is `false` if this element is an initializing formal.
-  /// See [isInitializingFormal].
-  bool get isParameter => kind == ElementKind.PARAMETER;
-
-  /// `true` if this element is an initializing formal of constructor, that
-  /// is a formal of the form `this.foo`.
-  bool get isInitializingFormal => kind == ElementKind.INITIALIZING_FORMAL;
-
-  /// `true` if this element represents a resolution error.
-  bool get isErroneous => kind == ElementKind.ERROR;
-
-  /// `true` if this element represents an ambiguous name.
-  ///
-  /// Ambiguous names occur when two imports/exports contain different entities
-  /// by the same name. If an ambiguous name is resolved an warning or error
-  /// is produced.
-  bool get isAmbiguous => kind == ElementKind.AMBIGUOUS;
-
-  /// `true` if this element represents an entity whose access causes one or
-  /// more warnings.
-  bool get isWarnOnUse => kind == ElementKind.WARN_ON_USE;
-
-  bool get isClosure;
-
-  /// `true` if the element is a (static or instance) member of a class.
-  ///
-  /// Members are constructors, methods and fields.
-  bool get isClassMember;
-
-  /// `true` if the element is a nonstatic member of a class.
-  ///
-  /// Instance members are methods and fields but not constructors.
-  bool get isInstanceMember;
-
-  /// Returns true if this [Element] is a top level element.
-  /// That is, if it is not defined within the scope of a class.
-  ///
-  /// This means whether the enclosing element is a compilation unit.
-  /// With the exception of [ClosureClassElement] that is considered top level
-  /// as all other classes.
-  bool get isTopLevel;
-  bool get isAssignable;
-  bool get isNative;
-  bool get isDeferredLoaderGetter;
-
-  /// True if the element is declared in a patch library but has no
-  /// corresponding declaration in the origin library.
-  bool get isInjected;
-
-  /// `true` if this element is a constructor, top level or local variable,
-  /// or static field that is declared `const`.
-  bool get isConst;
-
-  /// `true` if this element is a top level or local variable, static or
-  /// instance field, or parameter that is declared `final`.
-  bool get isFinal;
-
-  /// `true` if this element is a method, getter, setter or field that
-  /// is declared `static`.
-  bool get isStatic;
-
-  /// `true` if this element is local element, that is, a local variable,
-  /// local function or parameter.
-  bool get isLocal;
-
-  bool get impliesType;
-
-  Token get position;
-
-  CompilationUnitElement get compilationUnit;
-  LibraryElement get library;
-  LibraryElement get implementationLibrary;
-  ClassElement get enclosingClass;
-  Element get enclosingClassOrCompilationUnit;
-  Element get outermostEnclosingMemberOrTopLevel;
-
-  /// The enclosing class that defines the type environment for this element.
-  ClassElement get contextClass;
-
-  FunctionElement asFunctionElement();
-
-  /// Is [:true:] if this element has a corresponding patch.
-  ///
-  /// If [:true:] this element has a non-null [patch] field.
-  ///
-  /// See [:patch_parser.dart:] for a description of the terminology.
-  bool get isPatched;
-
-  /// Is [:true:] if this element is a patch.
-  ///
-  /// If [:true:] this element has a non-null [origin] field.
-  ///
-  /// See [:patch_parser.dart:] for a description of the terminology.
-  bool get isPatch;
-
-  /// Is [:true:] if this element defines the implementation for the entity of
-  /// this element.
-  ///
-  /// See [:patch_parser.dart:] for a description of the terminology.
-  bool get isImplementation;
-
-  /// Is [:true:] if this element introduces the entity of this element.
-  ///
-  /// See [:patch_parser.dart:] for a description of the terminology.
-  bool get isDeclaration;
-
-  /// Returns the element which defines the implementation for the entity of
-  /// this element.
-  ///
-  /// See [:patch_parser.dart:] for a description of the terminology.
-  Element get implementation;
-
-  /// Returns the element which introduces the entity of this element.
-  ///
-  /// See [:patch_parser.dart:] for a description of the terminology.
-  Element get declaration;
-
-  /// Returns the patch for this element if this element is patched.
-  ///
-  /// See [:patch_parser.dart:] for a description of the terminology.
-  Element get patch;
-
-  /// Returns the origin for this element if this element is a patch.
-  ///
-  /// See [:patch_parser.dart:] for a description of the terminology.
-  Element get origin;
-
-  bool get isSynthesized;
-  bool get isForwardingConstructor;
-  bool get isMixinApplication;
-
-  bool get hasFixedBackendName;
-  String get fixedBackendName;
-
-  bool get isAbstract;
-  bool isForeign(Backend backend);
-
-  void addMetadata(MetadataAnnotation annotation);
-  void setNative(String name);
-  void setFixedBackendName(String name);
-
-  Scope buildScope();
-
-  void diagnose(Element context, DiagnosticListener listener);
-
-  // TODO(johnniwinther): Move this to [AstElement].
-  /// Returns the [Element] that holds the [TreeElements] for this element.
-  AnalyzableElement get analyzableElement;
-
-  accept(ElementVisitor visitor);
-}
-
-class Elements {
-  static bool isUnresolved(Element e) {
-    return e == null || e.isErroneous;
-  }
-  static bool isErroneousElement(Element e) => e != null && e.isErroneous;
-
-  /// Unwraps [element] reporting any warnings attached to it, if any.
-  static Element unwrap(Element element,
-                        DiagnosticListener listener,
-                        Spannable spannable) {
-    if (element != null && element.isWarnOnUse) {
-      WarnOnUseElement wrappedElement = element;
-      element = wrappedElement.unwrap(listener, spannable);
-    }
-    return element;
-  }
-
-  static bool isClass(Element e) => e != null && e.kind == ElementKind.CLASS;
-  static bool isTypedef(Element e) {
-    return e != null && e.kind == ElementKind.TYPEDEF;
-  }
-
-  static bool isLocal(Element element) {
-    return !Elements.isUnresolved(element) && element.isLocal;
-  }
-
-  static bool isInstanceField(Element element) {
-    return !Elements.isUnresolved(element)
-           && element.isInstanceMember
-           && (identical(element.kind, ElementKind.FIELD)
-               || identical(element.kind, ElementKind.GETTER)
-               || identical(element.kind, ElementKind.SETTER));
-  }
-
-  static bool isStaticOrTopLevel(Element element) {
-    // TODO(johnniwinther): Clean this up. This currently returns true for a
-    // PartialConstructorElement, SynthesizedConstructorElementX, and
-    // TypeVariableElementX though neither `element.isStatic` nor
-    // `element.isTopLevel` is true.
-    if (Elements.isUnresolved(element)) return false;
-    if (element.isStatic || element.isTopLevel) return true;
-    return !element.isAmbiguous
-           && !element.isInstanceMember
-           && !element.isPrefix
-           && element.enclosingElement != null
-           && (element.enclosingElement.kind == ElementKind.CLASS ||
-               element.enclosingElement.kind == ElementKind.COMPILATION_UNIT ||
-               element.enclosingElement.kind == ElementKind.LIBRARY ||
-               element.enclosingElement.kind == ElementKind.PREFIX);
-  }
-
-  static bool isInStaticContext(Element element) {
-    if (isUnresolved(element)) return true;
-    if (element.enclosingElement.isClosure) {
-      var closureClass = element.enclosingElement;
-      element = closureClass.methodElement;
-    }
-    Element outer = element.outermostEnclosingMemberOrTopLevel;
-    if (isUnresolved(outer)) return true;
-    if (outer.isTopLevel) return true;
-    if (outer.isGenerativeConstructor) return false;
-    if (outer.isInstanceMember) return false;
-    return true;
-  }
-
-  static bool isStaticOrTopLevelField(Element element) {
-    return isStaticOrTopLevel(element)
-           && (identical(element.kind, ElementKind.FIELD)
-               || identical(element.kind, ElementKind.GETTER)
-               || identical(element.kind, ElementKind.SETTER));
-  }
-
-  static bool isStaticOrTopLevelFunction(Element element) {
-    return isStaticOrTopLevel(element)
-           && (identical(element.kind, ElementKind.FUNCTION));
-  }
-
-  static bool isInstanceMethod(Element element) {
-    return !Elements.isUnresolved(element)
-           && element.isInstanceMember
-           && (identical(element.kind, ElementKind.FUNCTION));
-  }
-
-  /// Also returns true for [ConstructorBodyElement]s and getters/setters.
-  static bool isNonAbstractInstanceMember(Element element) {
-    // The generative constructor body is not a function. We therefore treat
-    // it specially.
-    if (element.isGenerativeConstructorBody) return true;
-    return !Elements.isUnresolved(element) &&
-        !element.isAbstract &&
-        element.isInstanceMember &&
-        (element.isFunction || element.isAccessor);
-  }
-
-  static bool isNativeOrExtendsNative(ClassElement element) {
-    if (element == null) return false;
-    if (element.isNative) return true;
-    assert(element.resolutionState == STATE_DONE);
-    return isNativeOrExtendsNative(element.superclass);
-  }
-
-  static bool isInstanceSend(Send send, TreeElements elements) {
-    Element element = elements[send];
-    if (element == null) return !isClosureSend(send, element);
-    return isInstanceMethod(element) || isInstanceField(element);
-  }
-
-  static bool isClosureSend(Send send, Element element) {
-    if (send.isPropertyAccess) return false;
-    if (send.receiver != null) return false;
-    Node selector = send.selector;
-    // this().
-    if (selector.isThis()) return true;
-    // (o)() or foo()().
-    if (element == null && selector.asIdentifier() == null) return true;
-    if (element == null) return false;
-    // foo() with foo a local or a parameter.
-    return isLocal(element);
-  }
-
-  static String reconstructConstructorNameSourceString(Element element) {
-    if (element.name == '') {
-      return element.enclosingClass.name;
-    } else {
-      return reconstructConstructorName(element);
-    }
-  }
-
-  // TODO(johnniwinther): Remove this method.
-  static String reconstructConstructorName(Element element) {
-    String className = element.enclosingClass.name;
-    if (element.name == '') {
-      return className;
-    } else {
-      return '$className\$${element.name}';
-    }
-  }
-
-  static String constructorNameForDiagnostics(String className,
-                                              String constructorName) {
-    String classNameString = className;
-    String constructorNameString = constructorName;
-    return (constructorName == '')
-        ? classNameString
-        : "$classNameString.$constructorNameString";
-  }
-
-  /// Returns `true` if [name] is the name of an operator method.
-  static bool isOperatorName(String name) {
-    return name == 'unary-' || isUserDefinableOperator(name);
-  }
-
-  /**
-   * Map an operator-name to a valid JavaScript identifier.
-   *
-   * For non-operator names, this method just returns its input.
-   *
-   * The results returned from this method are guaranteed to be valid
-   * JavaScript identifers, except it may include reserved words for
-   * non-operator names.
-   */
-  static String operatorNameToIdentifier(String name) {
-    if (name == null) {
-      return name;
-    } else if (identical(name, '==')) {
-      return r'operator$eq';
-    } else if (identical(name, '~')) {
-      return r'operator$not';
-    } else if (identical(name, '[]')) {
-      return r'operator$index';
-    } else if (identical(name, '[]=')) {
-      return r'operator$indexSet';
-    } else if (identical(name, '*')) {
-      return r'operator$mul';
-    } else if (identical(name, '/')) {
-      return r'operator$div';
-    } else if (identical(name, '%')) {
-      return r'operator$mod';
-    } else if (identical(name, '~/')) {
-      return r'operator$tdiv';
-    } else if (identical(name, '+')) {
-      return r'operator$add';
-    } else if (identical(name, '<<')) {
-      return r'operator$shl';
-    } else if (identical(name, '>>')) {
-      return r'operator$shr';
-    } else if (identical(name, '>=')) {
-      return r'operator$ge';
-    } else if (identical(name, '>')) {
-      return r'operator$gt';
-    } else if (identical(name, '<=')) {
-      return r'operator$le';
-    } else if (identical(name, '<')) {
-      return r'operator$lt';
-    } else if (identical(name, '&')) {
-      return r'operator$and';
-    } else if (identical(name, '^')) {
-      return r'operator$xor';
-    } else if (identical(name, '|')) {
-      return r'operator$or';
-    } else if (identical(name, '-')) {
-      return r'operator$sub';
-    } else if (identical(name, 'unary-')) {
-      return r'operator$negate';
-    } else {
-      return name;
-    }
-  }
-
-  static String constructOperatorNameOrNull(String op, bool isUnary) {
-    if (isMinusOperator(op)) {
-      return isUnary ? 'unary-' : op;
-    } else if (isUserDefinableOperator(op)) {
-      return op;
-    } else {
-      return null;
-    }
-  }
-
-  static String constructOperatorName(String op, bool isUnary) {
-    String operatorName = constructOperatorNameOrNull(op, isUnary);
-    if (operatorName == null) throw 'Unhandled operator: $op';
-    else return operatorName;
-  }
-
-  static String mapToUserOperatorOrNull(String op) {
-    if (identical(op, '!=')) return '==';
-    if (identical(op, '*=')) return '*';
-    if (identical(op, '/=')) return '/';
-    if (identical(op, '%=')) return '%';
-    if (identical(op, '~/=')) return '~/';
-    if (identical(op, '+=')) return '+';
-    if (identical(op, '-=')) return '-';
-    if (identical(op, '<<=')) return '<<';
-    if (identical(op, '>>=')) return '>>';
-    if (identical(op, '&=')) return '&';
-    if (identical(op, '^=')) return '^';
-    if (identical(op, '|=')) return '|';
-
-    return null;
-  }
-
-  static String mapToUserOperator(String op) {
-    String userOperator = mapToUserOperatorOrNull(op);
-    if (userOperator == null) throw 'Unhandled operator: $op';
-    else return userOperator;
-  }
-
-  static bool isNumberOrStringSupertype(Element element, Compiler compiler) {
-    LibraryElement coreLibrary = compiler.coreLibrary;
-    return (element == coreLibrary.find('Comparable'));
-  }
-
-  static bool isStringOnlySupertype(Element element, Compiler compiler) {
-    LibraryElement coreLibrary = compiler.coreLibrary;
-    return element == coreLibrary.find('Pattern');
-  }
-
-  static bool isListSupertype(Element element, Compiler compiler) {
-    LibraryElement coreLibrary = compiler.coreLibrary;
-    return element == coreLibrary.find('Iterable');
-  }
-
-  /// A `compareTo` function that places [Element]s in a consistent order based
-  /// on the source code order.
-  static int compareByPosition(Element a, Element b) {
-    if (identical(a, b)) return 0;
-    int r = a.library.compareTo(b.library);
-    if (r != 0) return r;
-    r = a.compilationUnit.compareTo(b.compilationUnit);
-    if (r != 0) return r;
-    Token positionA = a.position;
-    Token positionB = b.position;
-    int offsetA = positionA == null ? -1 : positionA.charOffset;
-    int offsetB = positionB == null ? -1 : positionB.charOffset;
-    r = offsetA.compareTo(offsetB);
-    if (r != 0) return r;
-    r = a.name.compareTo(b.name);
-    if (r != 0) return r;
-    // Same file, position and name.  If this happens, we should find out why
-    // and make the order total and independent of hashCode.
-    return a.hashCode.compareTo(b.hashCode);
-  }
-
-  static List<Element> sortedByPosition(Iterable<Element> elements) {
-    return elements.toList()..sort(compareByPosition);
-  }
-
-  static bool isFixedListConstructorCall(Element element,
-                                         Send node,
-                                         Compiler compiler) {
-    return element == compiler.unnamedListConstructor
-        && node.isCall
-        && !node.arguments.isEmpty
-        && node.arguments.tail.isEmpty;
-  }
-
-  static bool isGrowableListConstructorCall(Element element,
-                                            Send node,
-                                            Compiler compiler) {
-    return element == compiler.unnamedListConstructor
-        && node.isCall
-        && node.arguments.isEmpty;
-  }
-
-  static bool isFilledListConstructorCall(Element element,
-                                          Send node,
-                                          Compiler compiler) {
-    return element == compiler.filledListConstructor
-        && node.isCall
-        && !node.arguments.isEmpty
-        && !node.arguments.tail.isEmpty
-        && node.arguments.tail.tail.isEmpty;
-  }
-
-  static bool isConstructorOfTypedArraySubclass(Element element,
-                                                Compiler compiler) {
-    if (compiler.typedDataLibrary == null) return false;
-    if (!element.isConstructor) return false;
-    ConstructorElement constructor = element.implementation;
-    constructor = constructor.effectiveTarget;
-    ClassElement cls = constructor.enclosingClass;
-    return cls.library == compiler.typedDataLibrary
-        && cls.isNative
-        && compiler.world.isSubtypeOf(cls, compiler.typedDataClass)
-        && compiler.world.isSubtypeOf(cls, compiler.listClass)
-        && constructor.name == '';
-  }
-
-  static bool switchStatementHasContinue(SwitchStatement node,
-                                         TreeElements elements) {
-    for (SwitchCase switchCase in node.cases) {
-      for (Node labelOrCase in switchCase.labelsAndCases) {
-        Node label = labelOrCase.asLabel();
-        if (label != null) {
-          LabelDefinition labelElement = elements.getLabelDefinition(label);
-          if (labelElement != null && labelElement.isContinueTarget) {
-            return true;
-          }
-        }
-      }
-    }
-    return false;
-  }
-
-  static bool isUnusedLabel(LabeledStatement node, TreeElements elements) {
-    Node body = node.statement;
-    JumpTarget element = elements.getTargetDefinition(body);
-    // Labeled statements with no element on the body have no breaks.
-    // A different target statement only happens if the body is itself
-    // a break or continue for a different target. In that case, this
-    // label is also always unused.
-    return element == null || element.statement != body;
-  }
-}
-
-/// An element representing an erroneous resolution.
-///
-/// An [ErroneousElement] is used instead of `null` to provide additional
-/// information about the error that caused the element to be unresolvable
-/// or otherwise invalid.
-///
-/// Accessing any field or calling any method defined on [ErroneousElement]
-/// except [isErroneous] will currently throw an exception. (This might
-/// change when we actually want more information on the erroneous element,
-/// e.g., the name of the element we were trying to resolve.)
-///
-/// Code that cannot not handle an [ErroneousElement] should use
-/// `Element.isUnresolved(element)` to check for unresolvable elements instead
-/// of `element == null`.
-abstract class ErroneousElement extends Element implements ConstructorElement {
-  MessageKind get messageKind;
-  Map get messageArguments;
-  String get message;
-}
-
-/// An [Element] whose usage should cause one or more warnings.
-abstract class WarnOnUseElement extends Element {
-  /// The element whose usage cause a warning.
-  Element get wrappedElement;
-
-  /// Reports the attached warning and returns the wrapped element.
-  /// [usageSpannable] is used to report messages on the reference of
-  /// [wrappedElement].
-  Element unwrap(DiagnosticListener listener, Spannable usageSpannable);
-}
-
-/// An ambiguous element represents multiple elements accessible by the same
-/// name.
-///
-/// Ambiguous elements are created during handling of import/export scopes. If
-/// an ambiguous element is encountered during resolution a warning/error is
-/// reported.
-abstract class AmbiguousElement extends Element {
-  MessageKind get messageKind;
-  Map get messageArguments;
-  Element get existingElement;
-  Element get newElement;
-}
-
-// TODO(kasperl): This probably shouldn't be called an element. It's
-// just an interface shared by classes and libraries.
-abstract class ScopeContainerElement implements Element {
-  Element localLookup(String elementName);
-
-  void forEachLocalMember(f(Element element));
-}
-
-abstract class CompilationUnitElement extends Element {
-  Script get script;
-  PartOf get partTag;
-
-  void forEachLocalMember(f(Element element));
-  void addMember(Element element, DiagnosticListener listener);
-  void setPartOf(PartOf tag, DiagnosticListener listener);
-  bool get hasMembers;
-
-  int compareTo(CompilationUnitElement other);
-}
-
-abstract class LibraryElement extends Element
-    implements ScopeContainerElement, AnalyzableElement {
-  /**
-   * The canonical uri for this library.
-   *
-   * For user libraries the canonical uri is the script uri. For platform
-   * libraries the canonical uri is of the form [:dart:x:].
-   */
-  Uri get canonicalUri;
-
-  /// Returns `true` if this library is 'dart:core'.
-  bool get isDartCore;
-
-  CompilationUnitElement get entryCompilationUnit;
-  Link<CompilationUnitElement> get compilationUnits;
-  Iterable<LibraryTag> get tags;
-  LibraryName get libraryTag;
-  Link<Element> get exports;
-
-  /**
-   * [:true:] if this library is part of the platform, that is, its canonical
-   * uri has the scheme 'dart'.
-   */
-  bool get isPlatformLibrary;
-
-  /**
-   * [:true:] if this library is from a package, that is, its canonical uri has
-   * the scheme 'package'.
-   */
-  bool get isPackageLibrary;
-
-  /**
-   * [:true:] if this library is a platform library whose path starts with
-   * an underscore.
-   */
-  bool get isInternalLibrary;
-  bool get canUseNative;
-  bool get exportsHandled;
-
-  // TODO(kasperl): We should try to get rid of these.
-  void set canUseNative(bool value);
-  void set libraryTag(LibraryName value);
-
-  LibraryElement get implementation;
-
-  void addCompilationUnit(CompilationUnitElement element);
-  void addTag(LibraryTag tag, DiagnosticListener listener);
-  void addImport(Element element, Import import, DiagnosticListener listener);
-
-  /// Record which element an import or export tag resolved to.
-  /// (Belongs on builder object).
-  void recordResolvedTag(LibraryDependency tag, LibraryElement library);
-
-  /// Return the library element corresponding to an import or export.
-  LibraryElement getLibraryFromTag(LibraryDependency tag);
-
-  void addMember(Element element, DiagnosticListener listener);
-  void addToScope(Element element, DiagnosticListener listener);
-
-  // TODO(kasperl): Get rid of this method.
-  Iterable<Element> getNonPrivateElementsInScope();
-
-  void setExports(Iterable<Element> exportedElements);
-
-  Element find(String elementName);
-  Element findLocal(String elementName);
-  Element findExported(String elementName);
-  void forEachExport(f(Element element));
-
-  /// Returns the imports that import element into this library.
-  Link<Import> getImportsFor(Element element);
-
-  bool hasLibraryName();
-  String getLibraryName();
-  String getLibraryOrScriptName();
-
-  int compareTo(LibraryElement other);
-}
-
-/// The implicit scope defined by a import declaration with a prefix clause.
-abstract class PrefixElement extends Element {
-  void addImport(Element element, Import import, DiagnosticListener listener);
-  Element lookupLocalMember(String memberName);
-  /// Is true if this prefix belongs to a deferred import.
-  bool get isDeferred;
-  void markAsDeferred(Import import);
-  Import get deferredImport;
-}
-
-/// A type alias definition.
-abstract class TypedefElement extends Element
-    implements AstElement, TypeDeclarationElement, FunctionTypedElement {
-
-  /// The type defined by this typedef with the type variables as its type
-  /// arguments.
-  ///
-  /// For instance `F<T>` for `typedef void F<T>(T t)`.
-  TypedefType get thisType;
-
-  /// The type defined by this typedef with `dynamic` as its type arguments.
-  ///
-  /// For instance `F<dynamic>` for `typedef void F<T>(T t)`.
-  TypedefType get rawType;
-
-  /// The type, function type if well-defined, for which this typedef is an
-  /// alias.
-  ///
-  /// For instance `(int)->void` for `typedef void F(int)`.
-  DartType get alias;
-
-  void checkCyclicReference(Compiler compiler);
-}
-
-/// An executable element is an element that can hold code.
-///
-/// These elements variables (fields, parameters and locals), which can hold
-/// code in their initializer, and functions (including methods and
-/// constructors), which can hold code in their body.
-abstract class ExecutableElement extends Element
-    implements TypedElement, AstElement {
-  /// The outermost member that contains this element.
-  ///
-  /// For top level, static or instance members, the member context is the
-  /// element itself. For parameters, local variables and nested closures, the
-  /// member context is the top level, static or instance member in which it is
-  /// defined.
-  MemberElement get memberContext;
-}
-
-/// A top-level, static or instance field or method, or a constructor.
-///
-/// A [MemberElement] is the outermost executable element for any executable
-/// context.
-abstract class MemberElement extends Element implements ExecutableElement {
-  /// The local functions defined within this member.
-  List<FunctionElement> get nestedClosures;
-}
-
-/// A function, variable or parameter defined in an executable context.
-abstract class LocalElement extends Element implements TypedElement, Local {
-}
-
-/// A top level, static or instance field, a formal parameter or local variable.
-abstract class VariableElement extends ExecutableElement {
-  Expression get initializer;
-}
-
-/// An entity that defines a local entity (memory slot) in generated code.
-///
-/// Parameters, local variables and local functions (can) define local entity
-/// and thus implement [Local] through [LocalElement]. For non-element locals,
-/// like `this` and boxes, specialized [Local] classes are created.
-///
-/// Type variables can introduce locals in factories and constructors
-/// but since one type variable can introduce different locals in different
-/// factories and constructors it is not itself a [Local] but instead
-/// a non-element [Local] is created through a specialized class.
-// TODO(johnniwinther): Should [Local] have `isAssignable` or `type`?
-abstract class Local extends Entity {
-  /// The context in which this local is defined.
-  ExecutableElement get executableContext;
-}
-
-/// A variable or parameter that is local to an executable context.
-///
-/// The executable context is the [ExecutableElement] in which this variable
-/// is defined.
-abstract class LocalVariableElement extends VariableElement
-    implements LocalElement {
-}
-
-/// A top-level, static or instance field.
-abstract class FieldElement extends VariableElement implements MemberElement {
-}
-
-/// A parameter-like element of a function signature.
-///
-/// If the function signature comes from a typedef or an inline function-typed
-/// parameter (e.g. the parameter 'f' in `method(void f())`), then its
-/// parameters are not real parameters in that they can take no argument and
-/// hold no value. Such parameter-like elements are modeled by [FormalElement].
-///
-/// If the function signature comes from a function or constructor, its
-/// parameters are real parameters and are modeled by [ParameterElement].
-abstract class FormalElement extends Element
-    implements FunctionTypedElement, TypedElement, AstElement {
-  /// Use [functionDeclaration] instead.
-  @deprecated
-  get enclosingElement;
-
-  /// The function, typedef or inline function-typed parameter on which
-  /// this parameter is declared.
-  FunctionTypedElement get functionDeclaration;
-
-  VariableDefinitions get node;
-}
-
-/// A formal parameter of a function or constructor.
-///
-/// Normal parameter that introduce a local variable are modeled by
-/// [LocalParameterElement] whereas initializing formals, that is parameter of
-/// the form `this.x`, are modeled by [InitializingFormalParameter].
-abstract class ParameterElement extends Element
-    implements VariableElement, FormalElement, LocalElement {
-  /// Use [functionDeclaration] instead.
-  @deprecated
-  get enclosingElement;
-
-  /// The function on which this parameter is declared.
-  FunctionElement get functionDeclaration;
-}
-
-/// A formal parameter on a function or constructor that introduces a local
-/// variable in the scope of the function or constructor.
-abstract class LocalParameterElement extends ParameterElement
-    implements LocalVariableElement {
-}
-
-/// A formal parameter in a constructor that directly initializes a field.
-///
-/// For example: `A(this.field)`.
-abstract class InitializingFormalElement extends ParameterElement {
-  /// The field initialized by this initializing formal.
-  FieldElement get fieldElement;
-
-  /// The function on which this parameter is declared.
-  ConstructorElement get functionDeclaration;
-}
-
-/**
- * A synthetic element which holds a getter and/or a setter.
- *
- * This element unifies handling of fields and getters/setters.  When
- * looking at code like "foo.x", we don't have to look for both a
- * field named "x", a getter named "x", and a setter named "x=".
- */
-abstract class AbstractFieldElement extends Element {
-  FunctionElement get getter;
-  FunctionElement get setter;
-}
-
-abstract class FunctionSignature {
-  FunctionType get type;
-  Link<FormalElement> get requiredParameters;
-  Link<FormalElement> get optionalParameters;
-
-  int get requiredParameterCount;
-  int get optionalParameterCount;
-  bool get optionalParametersAreNamed;
-  FormalElement get firstOptionalParameter;
-  bool get hasOptionalParameters;
-
-  int get parameterCount;
-  List<FormalElement> get orderedOptionalParameters;
-
-  void forEachParameter(void function(FormalElement parameter));
-  void forEachRequiredParameter(void function(FormalElement parameter));
-  void forEachOptionalParameter(void function(FormalElement parameter));
-
-  void orderedForEachParameter(void function(FormalElement parameter));
-
-  bool isCompatibleWith(FunctionSignature constructorSignature);
-}
-
-/// A top level, static or instance method, constructor, local function, or
-/// closure (anonymous local function).
-abstract class FunctionElement extends Element
-    implements AstElement,
-               TypedElement,
-               FunctionTypedElement,
-               ExecutableElement {
-  FunctionExpression get node;
-
-  FunctionElement get patch;
-  FunctionElement get origin;
-
-  /// Used to retrieve a link to the abstract field element representing this
-  /// element.
-  AbstractFieldElement get abstractField;
-
-  /// Do not use [computeSignature] outside of the resolver; instead retrieve
-  /// the signature through the [functionSignature] field.
-  /// Trying to access a function signature that has not been computed in
-  /// resolution is an error and calling [computeSignature] covers that error.
-  /// This method will go away!
-  // TODO(johnniwinther): Rename to `ensureFunctionSignature`.
-  @deprecated FunctionSignature computeSignature(Compiler compiler);
-
-  bool get hasFunctionSignature;
-
-  /// The type of this function.
-  FunctionType get type;
-
-  /// The synchronous/asynchronous marker on this function.
-  AsyncMarker get asyncMarker;
-}
-
-/// Enum for the synchronous/asynchronous function body modifiers.
-class AsyncMarker {
-  /// The default function body marker.
-  static AsyncMarker SYNC = const AsyncMarker._();
-
-  /// The `sync*` function body marker.
-  static AsyncMarker SYNC_STAR = const AsyncMarker._(isYielding: true);
-
-  /// The `async` function body marker.
-  static AsyncMarker ASYNC = const AsyncMarker._(isAsync: true);
-
-  /// The `async*` function body marker.
-  static AsyncMarker ASYNC_STAR =
-      const AsyncMarker._(isAsync: true, isYielding: true);
-
-  /// Is `true` if this marker defines the function body to have an
-  /// asynchronous result, that is, either a [Future] or a [Stream].
-  final bool isAsync;
-
-  /// Is `true` if this marker defines the function body to have a plural
-  /// result, that is, either an [Iterable] or a [Stream].
-  final bool isYielding;
-
-  const AsyncMarker._({this.isAsync: false, this.isYielding: false});
-
-  String toString() {
-    return '${isAsync ? 'async' : 'sync'}${isYielding ? '*' : ''}';
-  }
-}
-
-/// A top level, static or instance function.
-abstract class MethodElement extends FunctionElement
-    implements MemberElement {
-}
-
-/// A local function or closure (anonymous local function).
-abstract class LocalFunctionElement extends FunctionElement
-    implements LocalElement {
-}
-
-/// A constructor.
-abstract class ConstructorElement extends FunctionElement
-    implements MemberElement {
-  /// The effective target of this constructor, that is the non-redirecting
-  /// constructor that is called on invocation of this constructor.
-  ///
-  /// Consider for instance this hierachy:
-  ///
-  ///     class C { factory C.c() = D.d; }
-  ///     class D { factory D.d() = E.e2; }
-  ///     class E { E.e1();
-  ///               E.e2() : this.e1(); }
-  ///
-  /// The effective target of both `C.c`, `D.d`, and `E.e2` is `E.e2`, and the
-  /// effective target of `E.e1` is `E.e1` itself.
-  ConstructorElement get effectiveTarget;
-
-  /// The immediate redirection target of a redirecting factory constructor.
-  ///
-  /// Consider for instance this hierachy:
-  ///
-  ///     class C { factory C() = D; }
-  ///     class D { factory D() = E; }
-  ///     class E { E(); }
-  ///
-  /// The immediate redirection target of `C` is `D` and the immediate
-  /// redirection target of `D` is `E`. `E` is not a redirecting factory
-  /// constructor so its immediate redirection target is `null`.
-  ConstructorElement get immediateRedirectionTarget;
-
-  /// Is `true` if this constructor is a redirecting factory constructor.
-  bool get isRedirectingFactory;
-
-  /// Compute the type of the effective target of this constructor for an
-  /// instantiation site with type [:newType:].
-  InterfaceType computeEffectiveTargetType(InterfaceType newType);
-
-  /// If this is a synthesized constructor [definingConstructor] points to
-  /// the generative constructor from which this constructor was created.
-  /// Otherwise [definingConstructor] is `null`.
-  ///
-  /// Consider for instance this hierarchy:
-  ///
-  ///     class C { C.c(a, {b});
-  ///     class D {}
-  ///     class E = C with D;
-  ///
-  /// Class `E` has a synthesized constructor, `E.c`, whose defining constructor
-  /// is `C.c`.
-  ConstructorElement get definingConstructor;
-
-  /// Use [enclosingClass] instead.
-  @deprecated
-  get enclosingElement;
-}
-
-/// JavaScript backend specific element for the body of constructor.
-// TODO(johnniwinther): Remove this class for the element model.
-abstract class ConstructorBodyElement extends FunctionElement {
-  FunctionElement get constructor;
-}
-
-/// [TypeDeclarationElement] defines the common interface for class/interface
-/// declarations and typedefs.
-abstract class TypeDeclarationElement extends Element implements AstElement {
-  /**
-   * The `this type` for this type declaration.
-   *
-   * The type of [:this:] is the generic type based on this element in which
-   * the type arguments are the declared type variables. For instance,
-   * [:List<E>:] for [:List:] and [:Map<K,V>:] for [:Map:].
-   *
-   * For a class declaration this is the type of [:this:].
-   */
-  GenericType get thisType;
-
-  /**
-   * The raw type for this type declaration.
-   *
-   * The raw type is the generic type base on this element in which the type
-   * arguments are all [dynamic]. For instance [:List<dynamic>:] for [:List:]
-   * and [:Map<dynamic,dynamic>:] for [:Map:]. For non-generic classes [rawType]
-   * is the same as [thisType].
-   *
-   * The [rawType] field is a canonicalization of the raw type and should be
-   * used to distinguish explicit and implicit uses of the [dynamic]
-   * type arguments. For instance should [:List:] be the [rawType] of the
-   * [:List:] class element whereas [:List<dynamic>:] should be its own
-   * instantiation of [InterfaceType] with [:dynamic:] as type argument. Using
-   * this distinction, we can print the raw type with type arguments only when
-   * the input source has used explicit type arguments.
-   */
-  GenericType get rawType;
-
-  /**
-   * The type variables declared on this declaration. The type variables are not
-   * available until the type of the element has been computed through
-   * [computeType].
-   */
-  List<DartType> get typeVariables;
-
-  bool get isResolved;
-
-  int get resolutionState;
-
-  void ensureResolved(Compiler compiler);
-}
-
-abstract class ClassElement extends TypeDeclarationElement
-    implements ScopeContainerElement {
-  int get id;
-
-  /// The length of the longest inheritance path from [:Object:].
-  int get hierarchyDepth;
-
-  InterfaceType get rawType;
-  InterfaceType get thisType;
-  ClassElement get superclass;
-
-  /// The direct supertype of this class.
-  DartType get supertype;
-
-  /// Ordered set of all supertypes of this class including the class itself.
-  OrderedTypeSet get allSupertypesAndSelf;
-
-  /// A list of all supertypes of this class excluding the class itself.
-  Link<DartType> get allSupertypes;
-
-  /// Returns the this type of this class as an instance of [cls].
-  InterfaceType asInstanceOf(ClassElement cls);
-
-  /// A list of all direct superinterfaces of this class.
-  Link<DartType> get interfaces;
-
-  bool get hasConstructor;
-  Link<Element> get constructors;
-
-  ClassElement get patch;
-  ClassElement get origin;
-  ClassElement get declaration;
-  ClassElement get implementation;
-
-  int get supertypeLoadState;
-  String get nativeTagInfo;
-
-  bool get isMixinApplication;
-  bool get isUnnamedMixinApplication;
-  bool get hasBackendMembers;
-  bool get hasLocalScopeMembers;
-
-  /// Returns `true` if this class is `Object` from dart:core.
-  bool get isObject;
-
-  bool isSubclassOf(ClassElement cls);
-  /// Returns true if `this` explicitly/nominally implements [intrface].
-  ///
-  /// Note that, if [intrface] is the `Function` class, this method returns
-  /// falso for a class that has a `call` method but does not explicitly
-  /// implement `Function`.
-  bool implementsInterface(ClassElement intrface);
-  bool hasFieldShadowedBy(Element fieldMember);
-
-  /// Returns `true` if this class has a @proxy annotation.
-  bool get isProxy;
-
-  /// Returns `true` if the class hierarchy for this class contains errors.
-  bool get hasIncompleteHierarchy;
-
-  void addMember(Element element, DiagnosticListener listener);
-  void addToScope(Element element, DiagnosticListener listener);
-
-  void setDefaultConstructor(FunctionElement constructor, Compiler compiler);
-
-  void addBackendMember(Element element);
-  void reverseBackendMembers();
-
-  Element lookupMember(String memberName);
-  Element lookupSelector(Selector selector);
-  Element lookupSuperSelector(Selector selector);
-
-  Element lookupLocalMember(String memberName);
-  Element lookupBackendMember(String memberName);
-  Element lookupSuperMember(String memberName);
-
-  Element lookupSuperMemberInLibrary(String memberName,
-                                     LibraryElement library);
-
-  Element validateConstructorLookupResults(Selector selector,
-                                           Element result,
-                                           Element noMatch(Element));
-
-  Element lookupConstructor(Selector selector, [Element noMatch(Element)]);
-
-  void forEachMember(void f(ClassElement enclosingClass, Element member),
-                     {bool includeBackendMembers: false,
-                      bool includeSuperAndInjectedMembers: false});
-
-  void forEachInstanceField(void f(ClassElement enclosingClass,
-                                   FieldElement field),
-                            {bool includeSuperAndInjectedMembers: false});
-
-  /// Similar to [forEachInstanceField] but visits static fields.
-  void forEachStaticField(void f(ClassElement enclosingClass, Element field));
-
-  void forEachBackendMember(void f(Element member));
-
-  List<DartType> computeTypeParameters(Compiler compiler);
-
-  /// Looks up the member [name] in this class.
-  Member lookupClassMember(Name name);
-
-  /// Calls [f] with each member of this class.
-  void forEachClassMember(f(Member member));
-
-  /// Looks up the member [name] in the interface of this class.
-  MemberSignature lookupInterfaceMember(Name name);
-
-  /// Calls [f] with each member of the interface of this class.
-  void forEachInterfaceMember(f(MemberSignature member));
-
-  /// Returns the type of the 'call' method in the interface of this class, or
-  /// `null` if the interface has no 'call' method.
-  FunctionType get callType;
-}
-
-abstract class MixinApplicationElement extends ClassElement {
-  ClassElement get mixin;
-  InterfaceType get mixinType;
-  void set mixinType(InterfaceType value);
-  void addConstructor(FunctionElement constructor);
-}
-
-/// The label entity defined by a labeled statement.
-abstract class LabelDefinition extends Entity {
-  Label get label;
-  String get labelName;
-  JumpTarget get target;
-
-  bool get isTarget;
-  bool get isBreakTarget;
-  bool get isContinueTarget;
-
-  void setBreakTarget();
-  void setContinueTarget();
-}
-
-/// A jump target is the reference point of a statement or switch-case,
-/// either by label or as the default target of a break or continue.
-abstract class JumpTarget extends Local {
-  Node get statement;
-  int get nestingLevel;
-  Link<LabelDefinition> get labels;
-
-  bool get isTarget;
-  bool get isBreakTarget;
-  bool get isContinueTarget;
-  bool get isSwitch;
-
-  // TODO(kasperl): Try to get rid of these.
-  void set isBreakTarget(bool value);
-  void set isContinueTarget(bool value);
-
-  LabelDefinition addLabel(Label label, String labelName);
-}
-
-/// The [Element] for a type variable declaration on a generic class or typedef.
-abstract class TypeVariableElement extends Element
-    implements AstElement, TypedElement {
-
-  /// Use [typeDeclaration] instead.
-  @deprecated
-  get enclosingElement;
-
-  /// The class or typedef on which this type variable is defined.
-  TypeDeclarationElement get typeDeclaration;
-
-  /// The [type] defined by the type variable.
-  TypeVariableType get type;
-
-  /// The upper bound on the type variable. If not explicitly declared, this is
-  /// `Object`.
-  DartType get bound;
-}
-
-abstract class MetadataAnnotation implements Spannable {
-  /// The front-end constant of this metadata annotation.
-  ConstantExpression get constant;
-  Element get annotatedElement;
-  int get resolutionState;
-  Token get beginToken;
-  Token get endToken;
-
-  bool get hasNode;
-  Node get node;
-
-  MetadataAnnotation ensureResolved(Compiler compiler);
-}
-
-/// An [Element] that has a type.
-abstract class TypedElement extends Element {
-  DartType get type;
-}
-
-/// An [Element] that can define a function type.
-abstract class FunctionTypedElement extends Element {
-  /// The function signature for the function type defined by this element,
-  /// if any.
-  FunctionSignature get functionSignature;
-}
-
-/// An [Element] that holds a [TreeElements] mapping.
-abstract class AnalyzableElement extends Element {
-  /// Return `true` if [treeElements] have been (partially) computed for this
-  /// element.
-  bool get hasTreeElements;
-
-  /// Returns the [TreeElements] that hold the resolution information for the
-  /// AST nodes of this element.
-  TreeElements get treeElements;
-}
-
-/// An [Element] that (potentially) has a node.
-///
-/// Synthesized elements may return `null` from [node].
-abstract class AstElement extends AnalyzableElement {
-  /// `true` if [node] is available and non-null.
-  bool get hasNode;
-
-  /// The AST node of this element.
-  Node get node;
-
-  /// `true` if [resolvedAst] is available.
-  bool get hasResolvedAst;
-
-  /// The defining AST node of this element with is corresponding
-  /// [TreeElements]. This is not available if [hasResolvedAst] is `false`.
-  ResolvedAst get resolvedAst;
-}
-
-class ResolvedAst {
-  final Element element;
-  final Node node;
-  final TreeElements elements;
-
-  ResolvedAst(this.element, this.node, this.elements);
-}
-
-/// A [MemberSignature] is a member of an interface.
-///
-/// A signature is either a method or a getter or setter, possibly implicitly
-/// defined by a field declarations. Fields themselves are not members of an
-/// interface.
-///
-/// A [MemberSignature] may be defined by a member declaration or may be
-/// synthetized from a set of declarations.
-abstract class MemberSignature {
-  /// The name of this member.
-  Name get name;
-
-  /// The type of the member when accessed. For getters and setters this is the
-  /// return type and argument type, respectively. For methods the type is the
-  /// [functionType] defined by the return type and parameters.
-  DartType get type;
-
-  /// The function type of the member. For a getter `Foo get foo` this is
-  /// `() -> Foo`, for a setter `void set foo(Foo _)` this is `(Foo) -> void`.
-  /// For methods the function type is defined by the return type and
-  /// parameters.
-  FunctionType get functionType;
-
-  /// Returns `true` if this member is a getter, possibly implictly defined by a
-  /// field declaration.
-  bool get isGetter;
-
-  /// Returns `true` if this member is a setter, possibly implictly defined by a
-  /// field declaration.
-  bool get isSetter;
-
-  /// Returns `true` if this member is a method, that is neither a getter nor
-  /// setter.
-  bool get isMethod;
-
-  /// Returns an iterable of the declarations that define this member.
-  Iterable<Member> get declarations;
-}
-
-/// A [Member] is a member of a class, that is either a method or a getter or
-/// setter, possibly implicitly defined by a field declarations. Fields
-/// themselves are not members of a class.
-///
-/// A [Member] of a class also defines a signature which is a member of the
-/// corresponding interface type.
-///
-/// A [Member] is implicitly concrete. An abstract declaration only declares
-/// a signature in the interface of its class.
-///
-/// A [Member] is always declared by an [Element] which is accessibly through
-/// the [element] getter.
-abstract class Member extends MemberSignature {
-  /// The [Element] that declared this member, possibly implicitly in case of
-  /// a getter or setter defined by a field.
-  Element get element;
-
-  /// The instance of the class that declared this member.
-  ///
-  /// For instance:
-  ///   class A<T> { T m() {} }
-  ///   class B<S> extends A<S> {}
-  /// The declarer of `m` in `A` is `A<T>` whereas the declarer of `m` in `B` is
-  /// `A<S>`.
-  InterfaceType get declarer;
-
-  /// Returns `true` if this member is static.
-  bool get isStatic;
-
-  /// Returns `true` if this member is a getter or setter implicitly declared
-  /// by a field.
-  bool get isDeclaredByField;
-
-  /// Returns `true` if this member is abstract.
-  bool get isAbstract;
-
-  /// If abstract, [implementation] points to the overridden concrete member,
-  /// if any. Otherwise [implementation] points to the member itself.
-  Member get implementation;
-}
-