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

pkg/compiler/lib/src/util/link.dart

-// Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
-// for details. All rights reserved. Use of this source code is governed by a
-// BSD-style license that can be found in the LICENSE file.
-
-part of dart2js.util;
-
-class Link<T> {
-  T get head => throw new StateError("no elements");
-  Link<T> get tail => null;
-
-  const Link();
-
-  Link<T> prepend(T element) {
-    return new LinkEntry<T>(element, this);
-  }
-
-  Iterator<T> get iterator => new LinkIterator<T>(this);
-
-  void printOn(StringBuffer buffer, [separatedBy]) {
-  }
-
-  List<T> toList({ bool growable: true }) {
-    List<T> result;
-    if (!growable) {
-      result = new List<T>(slowLength());
-    } else {
-      result = new List<T>();
-      result.length = slowLength();
-    }
-    int i = 0;
-    for (Link<T> link = this; !link.isEmpty; link = link.tail) {
-      result[i++] = link.head;
-    }
-    return result;
-  }
-
-  /// Lazily maps over this linked list, returning an [Iterable].
-  Iterable map(dynamic fn(T item)) {
-    return new MappedLinkIterable<T,dynamic>(this, fn);
-  }
-
-  /// Invokes `fn` for every item in the linked list and returns the results
-  /// in a [List].
-  List mapToList(dynamic fn(T item), { bool growable: true }) {
-    List result;
-    if (!growable) {
-      result = new List(slowLength());
-    } else {
-      result = new List();
-      result.length = slowLength();
-    }
-    int i = 0;
-    for (Link<T> link = this; !link.isEmpty; link = link.tail) {
-      result[i++] = fn(link.head);
-    }
-    return result;
-  }
-
-  /// Invokes `fn` for every item in the linked list and returns the results
-  /// in a [Set].
-  Set mapToSet(dynamic fn(T item)) {
-    Set result = new Set();
-    for (Link<T> link = this; !link.isEmpty; link = link.tail) {
-      result.add(fn(link.head));
-    }
-    return result;
-  }
-
-  bool get isEmpty => true;
-
-  Link<T> reverse() => this;
-
-  Link<T> reversePrependAll(Link<T> from) {
-    if (from.isEmpty) return this;
-    return this.prepend(from.head).reversePrependAll(from.tail);
-  }
-
-  Link<T> skip(int n) {
-    if (n == 0) return this;
-    throw new RangeError('Index $n out of range');
-  }
-
-  void forEach(void f(T element)) {}
-
-  bool operator ==(other) {
-    if (other is !Link<T>) return false;
-    return other.isEmpty;
-  }
-
-  int get hashCode => throw new UnsupportedError('Link.hashCode');
-
-  String toString() => "[]";
-
-  get length {
-    throw new UnsupportedError('get:length');
-  }
-
-  int slowLength() => 0;
-
-  // TODO(ahe): Remove this method?
-  bool contains(T element) {
-    for (Link<T> link = this; !link.isEmpty; link = link.tail) {
-      if (link.head == element) return true;
-    }
-    return false;
-  }
-
-  // TODO(ahe): Remove this method?
-  T get single {
-    if (isEmpty) throw new StateError('No elements');
-    if (!tail.isEmpty) throw new StateError('More than one element');
-    return head;
-  }
-
-  // TODO(ahe): Remove this method?
-  T get first {
-    if (isEmpty) throw new StateError('No elements');
-    return head;
-  }
-
-  /// Returns true if f returns true for all elements of this list.
-  ///
-  /// Returns true for the empty list.
-  bool every(bool f(T)) {
-    for (Link<T> link = this; !link.isEmpty; link = link.tail){
-      if (!f(link.head)) return false;
-    }
-    return true;
-  }
-}
-
-abstract class LinkBuilder<T> {
-  factory LinkBuilder() = LinkBuilderImplementation;
-
-  /**
-   * Prepends all elements added to the builder to [tail]. The resulting list is
-   * returned and the builder is cleared.
-   */
-  Link<T> toLink([Link<T> tail = const Link()]);
-
-  List<T> toList();
-
-  void addLast(T t);
-
-  final int length;
-  final bool isEmpty;
-}