Kotlin 1.0 Beta 3 发布基于 JVM 的编程语言

Kotlin 1.0 Beta 3 发布，此版本主要是要完成标准库开发，还有移除一些废弃的语言结构。同时还有一些 bug 修复，性能提升。此版本包括库，语言，IDE 和 Android 扩展方面的改进和修复。详细改进内容请看发行说明。

改进列表：

Library
- increment deprecated in Progressions in favor of step property to Progressions,for-loops updated to refer to step
- contains() and other similar extensions now accept supertypes of the element of the collection
- Delegates.mapVal and mapVar, MapVal, MapVar, FixedMapVal, FixedMapVar are deprecated
- String.toCharArray() introduced instead of String.getChars(); String.toCharList()deprecated
- MutableCollection.removeAll(predicate: (T) -> Boolean) and similar for retainAlladded
- sequence(initialValueFunction, nextValueFunction) doesn’t evaluate first value until it’s requested by sequence iterator
- sequenceOf(Progression) deprecated
- flatten operation for Sequence<Iterable<...>> added
Langauge
- No references to PropertyMetadata are generated in the byte code
- Suffixes to numeric literals, such as 1baz are prohibited
- Comma-separated conditions in when without an argument are prohibited (KT-5143)
- Annotation classes can’t be instantiated (KT-4391)
- Arrays of annotations supported as annotation arguments (KT-10136)
- Generic types in catch clauses (including reified T) are prohibited (KT-9816)
- protected members are allowed in companion objects
- Calls to non-@JvmStatic protected members of companion objects from subclasses are marked as errors (unsupported)
- “…” is reserved as a token (KT-9708)
- Enum entry can not be used as a type (KT-5401)
- Enum.values is deprecated in favor of Enum.values()
- private setters are now deprecated for open properties
- Local sealed classes are deprecated
- Use of uninitialized variables in lambdas / object literals / local functions is forbidden
- Overriding setter cannot weaken visibility
- Inner classes are no longer allowed inside enum entries
- Implicit receiver smart casts are supported
- Older deprecations have become errors

下载：

kotlin-compiler-1.0.0-beta-3595.zip

Kotlin 是一个基于 JVM 的新的编程语言，由 JetBrains 开发。

其主要设计目标：

创建一种兼容Java的语言
让它比Java更安全，能够静态检测常见的陷阱。如：引用空指针
让它比Java更简洁，通过支持variable type inference，higher-order functions (closures)，extension functions，mixins and first-class delegation等实现。
让它比最成熟的竞争对手scala”>Scala语言更加简单。