Immutable.js 3.8.1 发布了，Immutable 是 Facebook 开发的不可变数据集合。不可变数据一旦创建就不能被修改，是的应用开发更简单，允许使用函数式编程技术，比如惰性评估。Immutable JS 提供一个惰性 Sequence，允许高效的队列方法链，类似 map 和 filter ，不用创建中间代表。 immutable 通过惰性队列和哈希映射提供 Sequence, Range, Repeat, Map, OrderedMap, Set 和一个稀疏 Vector。 新特性： The methods keyOf, findKey, lastKeyOf, and findLastKey were moved from KeyedIterable to Iterable, so they may be also used on Lists and Sets. (#740) Bug 修复: Some issues with the flow definitions have been polished out thanks to @marudor. (#840, #841, #845) Collections which contain Symbol keys or values can now be stringified. (#620) Negative indexing into the keySeq of an IndexedIterable returns correct results. (#811) Can use the value Infinity as a key in a Collection without crashing. (#797) 下载地址：https://github.com/facebook/immutable-js/releases/tag/v3.8.1 Immutable.js 3.8.1 发布，不可变数据集合下载地址
