| // Copyright 2013 Google Inc. All Rights Reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| part of quiver.iterables; |
| |
| /// Returns an infinite [Iterable] of [num]s, starting from [start] and |
| /// increasing by [step]. |
| Iterable<num> count([num start = 0, num step = 1]) => new _Count(start, step); |
| |
| class _Count extends InfiniteIterable<num> { |
| final num start, step; |
| |
| _Count(num this.start, num this.step); |
| |
| Iterator<num> get iterator => new _CountIterator(start, step); |
| |
| // TODO(justin): return an infinite list for toList() and a special Set |
| // implmentation for toSet()? |
| } |
| |
| class _CountIterator implements Iterator<num> { |
| final num _start, _step; |
| num _current; |
| |
| _CountIterator(num this._start, this._step); |
| |
| num get current => _current; |
| |
| bool moveNext() { |
| _current = (_current == null) ? _start : _current + _step; |
| return true; |
| } |
| } |