Add ImportElement and ExportElement

pkg/compiler/lib/src/elements/elements.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.
 
 library elements;
 
 import '../compiler.dart' show
     Compiler;
 import '../constants/constructors.dart';
 import '../constants/expressions.dart';
@@ skipping 88 matching lines @@
   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 IMPORT =
+      const ElementKind('import', ElementCategory.NONE);
+  static const ElementKind EXPORT =
+      const ElementKind('export', 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 =
@@ skipping 61 matching lines @@
  */
 abstract class Element implements Entity {
   String get name;
   ElementKind get kind;
   Element get enclosingElement;
   Iterable<MetadataAnnotation> get metadata;
 
   /// `true` if this element is a library.
   bool get isLibrary;
 
+  /// `true` if this element is an import declaration.
+  bool get isImport => kind == ElementKind.IMPORT;
+
+  /// `true` if this element is an export declaration.
+  bool get isExport => kind == ElementKind.EXPORT;
+
   /// `true` if this element is a compilation unit.
   bool get isCompilationUnit;
 
   /// `true` if this element is defines the scope of prefix used by one or
   /// more import declarations.
   bool get isPrefix;
 
   /// `true` if this element is a class declaration or a mixin application.
   bool get isClass;
 
@@ skipping 625 matching lines @@
   @deprecated
   get enclosingElement;
 
   Script get script;
 
   void forEachLocalMember(f(Element element));
 
   int compareTo(CompilationUnitElement other);
 }
 
+abstract class ImportElement extends Element {
+  Uri get uri;
+  LibraryElement get importedLibrary;
+  bool get isDeferred;
+  PrefixElement get prefix;
+  // TODO(johnniwinther): Remove this when no longer needed in source mirrors.
+  Import get node;
+}
+
+abstract class ExportElement extends Element {
+  Uri get uri;
+  LibraryElement get exportedLibrary;
+  // TODO(johnniwinther): Remove this when no longer needed in source mirrors.
+  Export get node;
+}
+
 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;
+
+  /// The import declarations in this library, including the implicit import of
+  /// 'dart:core', if present.
+  Iterable<ImportElement> get imports;
+
+  /// The export declarations in this library.
+  Iterable<ExportElement> 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;
 
   LibraryElement get implementation;
 
-  /// Return the library element corresponding to an import or export.
-  LibraryElement getLibraryFromTag(LibraryDependency tag);
-
   Element find(String elementName);
   Element findLocal(String elementName);
   Element findExported(String elementName);
   void forEachExport(f(Element element));
 
   /// Calls [f] for each [Element] imported into this library.
   void forEachImport(f(Element element));
 
   /// Returns the imports that import element into this library.
-  Link<Import> getImportsFor(Element element);
+  Iterable<ImportElement> getImportsFor(Element element);
 
-  bool hasLibraryName();
-  String getLibraryName();
+  /// `true` if this library has name as given through a library tag.
+  bool get hasLibraryName;
 
-  /**
-   * Returns the library name (as defined by the library tag) or for script
-   * (which have no library tag) the script file name. The latter case is used
-   * to provide a 'library name' for scripts to use for instance in dartdoc.
-   *
-   * Note: the returned filename is still escaped ("a%20b.dart" instead of
-   * "a b.dart").
-   */
-  String getLibraryOrScriptName();
+  /// The library name, which is either the name given in the library tag
+  /// or the empty string if there is no library tag.
+  String get libraryName;
+
+  /// Returns the library name (as defined by the library tag) or for script
+  /// (which have no library tag) the script file name. The latter case is used
+  /// to provide a 'library name' for scripts to use for instance in dartdoc.
+  ///
+  /// Note: the returned filename is still escaped ("a%20b.dart" instead of
+  /// "a b.dart").
+  String get libraryOrScriptName;
 
   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;
+
+  /// Import that declared this deferred prefix.
+  ImportElement 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)`.
@@ skipping 728 matching lines @@
   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;
 }