什么是Java 8“视图”？ [英] What is a Java 8 "view"?

问题描述

我正在观看Paul Philips的演讲：

I'm watching a talk by Paul Philips :

http://www.youtube.com/watch?v=TS1lpKBMkgg

在12:48他说在Java 8中他们的观点实际上有效比较Scala和Java

at 12:48 he says "in Java 8 their views actually work" when comparing Scala and Java

什么是Java视图以及什么是Scala的等价物？

What are Java "views" and what is Scala's equivalent ?

更新：感谢Daniel的回答我发现这篇文章很有帮助： http://www.scala-lang.org/ docu / files / collections-api / collections_42.html

update : Thanks to Daniel's answer I found this article helpful : http://www.scala-lang.org/docu/files/collections-api/collections_42.html

推荐答案

Java 8的 Stream 是他的意见。它们有两个重要属性：

Java 8's Stream is what he means by views. They have two important properties:

1. 它们是非严格的，这意味着它们只按需生成结果。


2. 他们将多个操作融合在一起，因此您可以执行多个 map 或过滤器调用，并且原始集合仍将只迭代一次。

1. They are non-strict, which means they only produce the result on-demand.
2. They "fuse" together multiple operations, so you can do multiple map or filter calls, and the original collection will still be iterated only once.

Scala的等价物是各种视图集合，您可以通过在现有集合上调用 .view 来获取。他们确实拥有这些属性 - 毕竟它们是定义属性 - 但却充满了缺陷和缺陷，更不用说非常复杂的实现了。

Scala's equivalent are the various View collections, which you can get by calling .view on an existing collection. They do have these properties -- they are the defining properties, after all -- but are plagued with deficiencies and bugs, not to mention a very complex implementation.

Paul has玩弄了替代它的实现，但从来没有优先取代它们。

Paul has toyed with alternative implementations for it on and off, but it has never been a priority replacing them.

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