Hide collection-dev library.

sdk/lib/collection_dev/iterable.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 dart.collection.dev;
-
-typedef T _Transformation<S, T>(S value);
-
-class MappedIterable<S, T> extends Iterable<T> {
-  final Iterable<S> _iterable;
-  // TODO(ahe): Restore type when feature is implemented in dart2js
-  // checked mode. http://dartbug.com/7733
-  final /* _Transformation<S, T> */ _f;
-
-  MappedIterable(this._iterable, T this._f(S element));
-
-  Iterator<T> get iterator => new MappedIterator<S, T>(_iterable.iterator, _f);
-
-  // Length related functions are independent of the mapping.
-  int get length => _iterable.length;
-  bool get isEmpty => _iterable.isEmpty;
-}
-
-class MappedIterator<S, T> extends Iterator<T> {
-  T _current;
-  final Iterator<S> _iterator;
-  // TODO(ahe): Restore type when feature is implemented in dart2js
-  // checked mode. http://dartbug.com/7733
-  final /* _Transformation<S, T> */ _f;
-
-  MappedIterator(this._iterator, T this._f(S element));
-
-  bool moveNext() {
-    if (_iterator.moveNext()) {
-      _current = _f(_iterator.current);
-      return true;
-    } else {
-      _current = null;
-      return false;
-    }
-  }
-
-  T get current => _current;
-}
-
-typedef bool _ElementPredicate<E>(E element);
-
-class WhereIterable<E> extends Iterable<E> {
-  final Iterable<E> _iterable;
-  // TODO(ahe): Restore type when feature is implemented in dart2js
-  // checked mode. http://dartbug.com/7733
-  final /* _ElementPredicate */ _f;
-
-  WhereIterable(this._iterable, bool this._f(E element));
-
-  Iterator<E> get iterator => new WhereIterator<E>(_iterable.iterator, _f);
-}
-
-class WhereIterator<E> extends Iterator<E> {
-  final Iterator<E> _iterator;
-  // TODO(ahe): Restore type when feature is implemented in dart2js
-  // checked mode. http://dartbug.com/7733
-  final /* _ElementPredicate */ _f;
-
-  WhereIterator(this._iterator, bool this._f(E element));
-
-  bool moveNext() {
-    while (_iterator.moveNext()) {
-      if (_f(_iterator.current)) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  E get current => _iterator.current;
-}
-
-class TakeIterable<E> extends Iterable<E> {
-  final Iterable<E> _iterable;
-  final int _takeCount;
-
-  TakeIterable(this._iterable, this._takeCount) {
-    if (_takeCount is! int || _takeCount < 0) {
-      throw new ArgumentError(_takeCount);
-    }
-  }
-
-  Iterator<E> get iterator {
-    return new TakeIterator<E>(_iterable.iterator, _takeCount);
-  }
-}
-
-class TakeIterator<E> extends Iterator<E> {
-  final Iterator<E> _iterator;
-  int _remaining;
-
-  TakeIterator(this._iterator, this._remaining) {
-    assert(_remaining is int && _remaining >= 0);
-  }
-
-  bool moveNext() {
-    _remaining--;
-    if (_remaining >= 0) {
-      return _iterator.moveNext();
-    }
-    _remaining = -1;
-    return false;
-  }
-
-  E get current {
-    if (_remaining < 0) return null;
-    return _iterator.current;
-  }
-}
-
-class TakeWhileIterable<E> extends Iterable<E> {
-  final Iterable<E> _iterable;
-  // TODO(ahe): Restore type when feature is implemented in dart2js
-  // checked mode. http://dartbug.com/7733
-  final /* _ElementPredicate */ _f;
-
-  TakeWhileIterable(this._iterable, bool this._f(E element));
-
-  Iterator<E> get iterator {
-    return new TakeWhileIterator<E>(_iterable.iterator, _f);
-  }
-}
-
-class TakeWhileIterator<E> extends Iterator<E> {
-  final Iterator<E> _iterator;
-  // TODO(ahe): Restore type when feature is implemented in dart2js
-  // checked mode. http://dartbug.com/7733
-  final /* _ElementPredicate */ _f;
-  bool _isFinished = false;
-
-  TakeWhileIterator(this._iterator, bool this._f(E element));
-
-  bool moveNext() {
-    if (_isFinished) return false;
-    if (!_iterator.moveNext() || !_f(_iterator.current)) {
-      _isFinished = true;
-      return false;
-    }
-    return true;
-  }
-
-  E get current {
-    if (_isFinished) return null;
-    return _iterator.current;
-  }
-}
-
-class SkipIterable<E> extends Iterable<E> {
-  final Iterable<E> _iterable;
-  final int _skipCount;
-
-  SkipIterable(this._iterable, this._skipCount) {
-    if (_skipCount is! int || _skipCount < 0) {
-      throw new ArgumentError(_skipCount);
-    }
-  }
-
-  Iterable<E> skip(int n) {
-    if (n is! int || n < 0) {
-      throw new ArgumentError(n);
-    }
-    return new SkipIterable<E>(_iterable, _skipCount + n);
-  }
-
-  Iterator<E> get iterator {
-    return new SkipIterator<E>(_iterable.iterator, _skipCount);
-  }
-}
-
-class SkipIterator<E> extends Iterator<E> {
-  final Iterator<E> _iterator;
-  int _skipCount;
-
-  SkipIterator(this._iterator, this._skipCount) {
-    assert(_skipCount is int && _skipCount >= 0);
-  }
-
-  bool moveNext() {
-    for (int i = 0; i < _skipCount; i++) _iterator.moveNext();
-    _skipCount = 0;
-    return _iterator.moveNext();
-  }
-
-  E get current => _iterator.current;
-}
-
-class SkipWhileIterable<E> extends Iterable<E> {
-  final Iterable<E> _iterable;
-  // TODO(ahe): Restore type when feature is implemented in dart2js
-  // checked mode. http://dartbug.com/7733
-  final /* _ElementPredicate */ _f;
-
-  SkipWhileIterable(this._iterable, bool this._f(E element));
-
-  Iterator<E> get iterator {
-    return new SkipWhileIterator<E>(_iterable.iterator, _f);
-  }
-}
-
-class SkipWhileIterator<E> extends Iterator<E> {
-  final Iterator<E> _iterator;
-  // TODO(ahe): Restore type when feature is implemented in dart2js
-  // checked mode. http://dartbug.com/7733
-  final /* _ElementPredicate */ _f;
-  bool _hasSkipped = false;
-
-  SkipWhileIterator(this._iterator, bool this._f(E element));
-
-  bool moveNext() {
-    if (!_hasSkipped) {
-      _hasSkipped = true;
-      while (_iterator.moveNext()) {
-        if (!_f(_iterator.current)) return true;
-      }
-    }
-    return _iterator.moveNext();
-  }
-
-  E get current => _iterator.current;
-}