Move frog/leg to lib/compiler/implementation.

frog/leg/util/link_implementation.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.
-
-class LinkIterator<T> implements Iterator<T> {
-  Link<T> current;
-  LinkIterator(Link<T> this.current);
-  bool hasNext() => !current.isEmpty();
-  T next() {
-    T result = current.head;
-    current = current.tail;
-    return result;
-  }
-}
-
-class LinkFactory<T> {
-  factory Link(T head, [Link<T> tail]) {
-    if (tail === null) {
-      tail = new LinkTail<T>();
-    }
-    return new LinkEntry<T>(head, tail);
-  }
-
-  factory Link.fromList(List<T> list) {
-    switch (list.length) {
-      case 0:
-        return new LinkTail<T>();
-      case 1:
-        return new Link<T>(list[0]);
-      case 2:
-        return new Link<T>(list[0], new Link<T>(list[1]));
-      case 3:
-        return new Link<T>(list[0], new Link<T>(list[1], new Link<T>(list[2])));
-    }
-    Link link = new Link<T>(list.last());
-    for (int i = list.length - 1; i > 0; i--) {
-      link = link.prepend(list[i - 1]);
-    }
-    return link;
-  }
-}
-
-class LinkTail<T> implements EmptyLink<T> {
-  T get head() => null;
-  Link<T> get tail() => null;
-
-  const LinkTail();
-
-  Link<T> prepend(T element) {
-    // TODO(ahe): Use new Link<T>, but this cost 8% performance on VM.
-    return new LinkEntry<T>(element, this);
-  }
-
-  Iterator<T> iterator() => new LinkIterator<T>(this);
-
-  void printOn(StringBuffer buffer, [separatedBy]) {
-  }
-
-  String toString() => "[]";
-
-  Link<T> reverse() => this;
-
-  Link<T> reversePrependAll(Link<T> from) {
-    if (from.isEmpty()) return this;
-    return from.head.reversePrependAll(from.tail);
-  }
-
-  List toList() => const [];
-
-  bool isEmpty() => true;
-
-  void forEach(void f(T element)) {}
-}
-
-class LinkEntry<T> implements Link<T> {
-  final T head;
-  Link<T> tail;
-
-  LinkEntry(T this.head, Link<T> this.tail);
-
-  Link<T> prepend(T element) {
-    // TODO(ahe): Use new Link<T>, but this cost 8% performance on VM.
-    return new LinkEntry<T>(element, this);
-  }
-
-  Iterator<T> iterator() => new LinkIterator<T>(this);
-
-  void printOn(StringBuffer buffer, [separatedBy]) {
-    buffer.add(head);
-    if (separatedBy === null) separatedBy = '';
-    for (Link link = tail; !link.isEmpty(); link = link.tail) {
-      buffer.add(separatedBy);
-      buffer.add(link.head);
-    }
-  }
-
-  String toString() {
-    StringBuffer buffer = new StringBuffer();
-    buffer.add('[ ');
-    printOn(buffer, ', ');
-    buffer.add(' ]');
-    return buffer.toString();
-  }
-
-  Link<T> reverse() {
-    Link<T> result = const LinkTail();
-    for (Link<T> link = this; !link.isEmpty(); link = link.tail) {
-      result = result.prepend(link.head);
-    }
-    return result;
-  }
-
-  Link<T> reversePrependAll(Link<T> from) {
-    Link<T> result;
-    for (result = this; !from.isEmpty(); from = from.tail) {
-      result = result.prepend(from.head);
-    }
-    return result;
-  }
-
-
-  bool isEmpty() => false;
-
-  List<T> toList() {
-    List<T> list = new List<T>();
-    for (Link<T> link = this; !link.isEmpty(); link = link.tail) {
-      list.addLast(link.head);
-    }
-    return list;
-  }
-
-  void forEach(void f(T element)) {
-    for (Link<T> link = this; !link.isEmpty(); link = link.tail) {
-      f(link.head);
-    }
-  }
-}
-
-class LinkBuilderImplementation<T> implements LinkBuilder<T> {
-  LinkEntry<T> head = null;
-  LinkEntry<T> lastLink = null;
-  int length = 0;
-
-  LinkBuilderImplementation();
-
-  Link<T> toLink() {
-    if (head === null) return const LinkTail();
-    lastLink.tail = const LinkTail();
-    Link<T> link = head;
-    lastLink = null;
-    head = null;
-    return link;
-  }
-
-  void addLast(T t) {
-    length++;
-    LinkEntry<T> entry = new LinkEntry<T>(t, null);
-    if (head === null) {
-      head = entry;
-    } else {
-      lastLink.tail = entry;
-    }
-    lastLink = entry;
-  }
-}