新闻 Kotlin 1.0 RC 发布，基于 JVM 的编程语言 下载

Kotlin 1.0 RC 发布，更新如下：

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  Language
  
  
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    new @delegate: use-site target for annotation (e.g. @delegate:Transient)
    
    
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    private top-level Kotlin classes should be compiled to package private java classes
    
    
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    unfinished multiline comment is an error
    
    
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    previously deprecated language constructs are now errors
    
    
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    type ckecking for use-site variance fixed
    
    
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    generic functions are compared for specificity through solving a constraint system
    
    
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    having multiple vararg parameters for one function is prohibited
    
    
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    super-calls to functions with default parameters are prohibited (pass all arguments explicitly)
    
    
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    implicit receiver behavior fixed
    
    
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    as-import removes original names if they were imported before
    
    
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    user code is not allowed in kotlin.** packages
    
    
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    type parameters of extension properties allowed to be indirectly used by the receiver type
    
    
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    members of private classes can-not be accessed from non-private inline functions
    
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  Java interop
  
  
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    forEach from Kotlin's library is preferred to forEach from java.lang.Iterable
    
    
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    synthesized declarations (like JavaBeans properties and SAM-converted methods) are now resolved on par with members
    
    
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    support added for Java setters that return values
    
    
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    previously depreacted Java declarations removed from generated code
    
    
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    private setters allowed for lateinit properties
    
    
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    wildcards are not generated for redundant type projections (use List<@JvmWildcard Foo> instead of List<out Foo>)
    
    
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    @Nullable/@NotNull annotations from different standard Java packages recognized (javax.annotations, Guava, Android, etc)
    
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  Standard Library
  
  
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    diagnostics for multiple conflicting Kotlin runtime versions in classpath
    
    
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    some functions have been made inline
    
    
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    many inline functions (most of them one-liners) can no longer be called from Java code. This will help us reduce the size of the runtime library in the future.
    
    
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    library code rearranged into more granular packages (no source changes should be required)
    
    
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    associate and associateBy are added to aid construction of maps associate and associateBy (instead of toMap/toMapBy)
    
    
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    groupBy with key- and value-selector functions
    
    
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    Map.getOrElse() and Map.getOrPut() now treat keys associated with null values as missing.
    
    
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    Map.getOrImplicitDefault() has been made internal
    
    
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    mutableListOf, mutableSetOf, mutableMapOf added to construct mutable collections. linkedListOf is deprecated
    
    
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    toMutableList added instead of toArrayList. The latter is deprecated
    
    
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    kotlin.system.exitProcess instead of System.exit
    
    
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    File.deleteRecursively only returns false in case of incomplete deletion
    
    
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    File.copyRecursively allows overwriting by specifying argument overwrite=true
    
    
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    changed File.copyTo behavior to be like Files.copy from JDK8.
    
    
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    more specific return type for File.inputStream, File.outputStream, String.byteInputStream.
    
    
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    IO utility functions taking charset name as a string are deprecated, use ones with Charset parameter.
    
    
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    File.useLines and Reader.readLines are introduced
    
    
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    File.(buffered)reader/writer now return less specific InputStreamReader/OutputStreamWriter and use UTF-8 encoding by default
    
    
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    Sequence and Iterable SAM constructor-like functions
    
    
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    Comparator- and comparison-related functions are moved to kotlin.comparisons package (not imported by default)
    
    
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    new properties in MatchResult: groupValues and destructured — provided for easier handling of regular expression match results
    
    
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    Lazy is now an interface open for implementation
    
    
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    kotlin.system.measureTimeNano renamed to measureNanoTime.
    
    
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    plusElement and minusElement functions as a synonyms for list + element and list - element.
    
    
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    kotlin.test.assertFailsWith with Class<T> parameter is deprecated, use an overload with KClass<T>.
    
    
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    toLinkedMap is deprecated.
    
    
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    UTF_32 charset properties added to Chatsets
    
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  Tools
  
  
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    To enable Android Extensions, use: apply plugin: 'kotlin-android-extensions'
    
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  IDE
  
  
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    Intention to replace iteration over map entries with a loop using a destructuring declaration
    
    
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    Inspection and quickfix to cleanup redundant visibility modifiers
    
    
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    Inspection to replace 'assert' calls checking that a variable is not null with !! or ?: error(...)
    
    
  • 
    Show "Kotlin not configured" notification when opening a .kt file in the IDE if the Kotlin runtime is not configured for the corresponding module
    
    
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    Action to generate the toString() method
    
    
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    Support for implementing members by primary constructor parameters
    
    
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    Parameter info popup works for showing type parameters
    
    
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    Completion offers name variants based on unresolved identifiers in current file
    
    
  • 
    Quickfix for adding missing branches to a when expression
    
    
  • 
    Support for moving nested classes to the upper level or into another top-level class
    
    
  • 
    @Suppress now works for IDE inspections
    

详情请看：发行说明

下载：here

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：

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  创建一种兼容Java的语言
  
  
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  让它比Java更安全，能够静态检测常见的陷阱。如：引用空指针
  
  
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  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。
  
  
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  让它比最成熟的竞争对手Scala语言更加简单。
  

Kotlin 1.0 RC 发布，基于 JVM 的编程语言下载地址