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现代化的JVM语言 Kotli v1.0.2发布

2010年，长达是十年之久的Java开发让JetBrains的工程师认为老旧的Java语言已经严重阻碍了生产力。他们认为是时候开发一款现代化的JVM语言了，这也是因为他们有足够的资源和专家。本身做各种IDEs起家的JetBrains就开始着手新工具的开发——一个编程语言。

Kotlin可以通过versa调用Java方法，源码可在同一项目中混合使用，甚至生成的.class文件完全兼容Java工具。JetBrains内部现在已经有一个超过20个开发人员的团队使用Kotlin开发。目前已经有大量的开发人员使用Kotlin开发web服务后端和Android应用。

更新日志

Analysis & diagnostics

KT-7437, KT-7971, KT-7051, KT-6125, KT-6186, KT-11649 Implement missing checks for protected visibility
KT-11666 Report "Implicit nothing return type" on non-override member functions
KT-4328, KT-11497, KT-10493, KT-10820, KT-11368 Report error if some classes were not found due to missing or conflicting dependencies
KT-11280 Do not perform smart casts for values with custom equals compared with ==
KT-3856 Fix wrong "inner class inaccessible" diagnostic for extension to outer class
KT-3896, KT-3883, KT-4986 do...while (true) is now considered an infinite loop
KT-10445 Prohibit initialization of captured val in lambda or in local function
KT-10042 Correctly handle local classes and anonymous objects in control flow analysis
KT-11043 Prohibit complex expressions with class literals in annotation arguments
KT-10992, KT-11007 Fix multiple problems related to smart casts
KT-11490 Prohibit nested intersection types in return position
KT-11411 Report "illegal noinline/crossinline" on parameter of subtype of function type
KT-3083 Report "conflicting overloads" for functions with parameter of type parameter type
KT-7265 Parse anonymous functions in blocks as expressions
KT-8246 Handle break/continue for outer loop correctly in case of try/finally in between
KT-11300 Report error on increment or augmented assignment when get is an operator but set is not
Report warning about unused anonymous functions
Improve callable reference type in some ambiguous cases
Improve multiple diagnostic messages: KT-10761, KT-9760, KT-10949, KT-9887, KT-9550, KT-11239, KT-11819
Fix several compiler bugs leading to exceptions: KT-9820, KT-11597, KT-10983, KT-10972, KT-11287, KT-11492, KT-11765, KT-11869

JVM code generation

KT-8269, KT-9246, KT-10143 Fix visibility of protected classes in bytecode
KT-11363 Fix potential binary compatibility breakage on using when over enums in inline functions
KT-11762 Fix VerifyError caused by explicit loop variable type
KT-11645 Fix NoSuchFieldError on private const property in multi-file class
KT-9670 Optimize Class <-> KClass wrapping/unwrapping when getting values from annotation
KT-6842 Optimize unnecessary boxing and interface calls on iterating over ranges
KT-11025 Don't inline const val properties in non-annotation contexts
KT-5429 Write nullability annotations on extension receiver parameters
KT-11347 Preserve source file and line number of call site when inlining certain standard library functions
KT-11677 Write correct generic signatures for local classes in inlined lambdas
KT-12127 Do not write unnecessary generic signature for property delegate backing field
Fix multiple issues leading to exceptions or bad bytecode being generated: KT-11034, KT-11519,KT-11117, KT-11479

Java interoperability

KT-3068 Load contravariantly projected collections in Java (List<? super T>) as mutable collections in Kotlin (MutableList<in T>)
KT-11322 Do not lose type nullability information in SAM constructors
KT-11721 Fix wrong "Typechecker has run into recursive problem" error on calling Kotlin get function as synthetic Java property
KT-10691 Fix wrong "Inherited platform declarations clash" error on inheritance from generic Java class with overloaded methods

Command line compiler

KT-9546 Flush stdout and stderr before shutdown when executing scripts
KT-10605 Disable colored output on certain platforms to prevent crashes
Report warning instead of error on unknown "-X" flags
Remove the compiler option "Xmultifile-facades-open"

Compiler daemon

Reduce read disk activity
Fix compiler daemon JAR cache clearing on IDEA Ultimate

Standard library

KT-11410 Reduce method count of the standard library by ~2k
KT-9990 Optimize snapshot operations to return special collection implementations when result is empty or has single element
KT-10794 EmptyList now implements RandomAccess
KT-10821 Create at most one wrapper sequence for adjacent drop/take operations on sequences
KT-11301 Make Map.plus accept Map out-projected by key type as either operand (receiver or parameter)
KT-11485 Remove implementations of some internal intrinsic functions
KT-11648 Add deprecated extension MutableList.remove to redirect to valid function removeAt
KT-11348 kotlin.test: Make inline methods todo and currentStackTrace @InlineOnly not to lose stack trace
KT-11745 Rename parameters of String.subSequence to match those of CharSequence.subSequence
KT-10953 Clarify parameter order of lambda function parameter of *Indexed functions
KT-10198 Improve docs for binarySearch functions
KT-9786 Improve docs for trimIndent/trimMargin

Reflection

KT-9952 Improve toString() for lambdas and function expressions when kotlin-reflect.jar is available
KT-11433 Fix multiple resource leaks by closing InputStream instances
KT-8131 Fix exception from calling KProperty.javaField on a subclass
KT-10690 Support javaMethod and kotlinFunction for top level functions in a different file
KT-11447 Support reflection calls to multifile class members
KT-10892 Load annotations of const properties from multifile classes
KT-11258 Don't crash on requesting members of Java collection classes
KT-11502 Clarify KClass equality

JS

KT-4124 Support nested classes
KT-11030 Support local classes
KT-7819 Support non-local returns in local lambdas
KT-6912 Safe calls (x?.let { it }) are now inlined
KT-2670 Support unsafe casts (as)
KT-7016, KT-8012 Fix is-checks for reified type parameters
KT-7038 Avoid unwanted side effects on is-checks for nullable types
KT-10614 Copy array on vararg call with spread operator
KT-10785 Correctly translate property names and receiver instances in assignment operations
KT-11611 Fix translation of default value of secondary constructor's functional parameter
KT-11100 Fix generation of invoke on objects and companion objects
KT-11823 Fix capturing of outer class' this in inner's lambdas
KT-11996 Fix translation of a call to a private member of an outer class from an inner class which is a subtype of the outer class
KT-10667 Support inheritance from nested built-in types such as Map.Entry
KT-7480 Remove declarations of LinkedList, SortedSet, TreeSet, Enumeration
KT-3064 Implement CharSequence.repeat

IDE

New features:

Spring Support
- KT-11098 Inspection on final classes/functions annotated with Spring@Configuration/@Component/@Bean
- KT-11405 Navigation and Find Usages for Spring beans referenced in annotation arguments and BeanFactory method calls
- KT-3741 Show Spring-specific line markers on Kotlin classes
- KT-11406 Support Spring EL injections inside of Kotlin string literals
- KT-11604 Support "Configure Spring facet" inspection on Kotlin classes
- KT-11407 Implement "Generate Spring Dependency..." actions
- KT-11408 Implement "Generate @Autowired Dependency..." action
- KT-11652 Rename bean attributes mentioned in Spring XML config together with corresponding Kotlin declarations
Enable precise incremental compilation by default in non-Maven/Gradle projects
KT-11612 Highlight named arguments
KT-7715 Highlight vars that can be replaced by vals
KT-5208 Intention action to convert string to raw string and back
KT-11078 Quick fix to remove .java when KClass is expected
KT-1494 Inspection to highlight public members with no documentation
KT-8473 Intention action to implement interface or abstract class
KT-10299 Inspection to warn on array properties in data classes
KT-6674 Inspection to warn on protected symbols in effectively final classes
KT-11576 Quick fix to suppress "Unused symbol" warning based on annotations on the declaration
KT-10063 Quick fix for adding arrayOf wrapper for annotation parameters
KT-10476 Quick fix for converting primitive types
KT-10859 Quick fix to make var with private setter final
KT-9498 Quick fix to specify property type
KT-10509 Quick fix to simplify condition with senseless comparison
KT-11404 Quick fix to let type implement missing interface
KT-6785, KT-10013, KT-9996, KT-11675 Support Smart Enter for trailing lambda argument, try/catch/finally, property setter, init block
Add kotlinClassName() and kotlinFunctionName() macros for use in live templates
Auto-configure EAP-repository during Kotlin Maven and Gradle project set up

Issues fixed:

KT-11678, KT-4768 Support navigation to Kotlin libraries from Java sources
KT-9401 Support Change Signature quick fix for Java -> Kotlin case
KT-8592 Fix "Choose sources" for Kotlin files
KT-11256 Fix Navigate to declaration for Java constructor with @NotNull parameter
KT-11018 Fix vars shown in Ctrl + Mouse Hover as vals
KT-5105, KT-11024 Improve incompatible ABI versions editor strap, show the hint on how to resolve the problem
KT-11638 Fixed hashCode() implementation in "Generate equals/hashCode" action
KT-10971 Pull Members Up: Always insert spaces between keywords
KT-11476, KT-4175, KT-10965, KT-11076 Formatter: fix multiple issues regarding space handling
KT-9025 Improve "Create Kotlin Java runtime library" dialog usability
KT-11481 Fix "Add import" intention not being available for is branches in when
KT-10619 Fix completion after package name in annotation
KT-10621 Do not show non-top level packages after @ in completion
KT-11295 "Convert string to template" intention: fix exception on certain code
KT-10750, KT-11424 "Convert if to when" intention now detects effectively else branches in subsequent code and performs more accurate comment handling
Configure Kotlin: show only changed files in the notification "Kotlin not configured", restore all changed files in undo action
KT-11556 Do not show "Kotlin not configured" for Kotlin JS projects
KT-11593 Fix "Configure Kotlin" action for Gradle projects in IDEA 2016
KT-11077 Use new built-in definition file format (.kotlin_builtins files)
KT-5728 Remove closing curly brace in a string template when opening one is deleted
KT-10883 "Explicit get or set call" quick fix: do not move caret too far away
KT-5717 "Replace 'when' with 'if'": do not lose comments
KT-10797 "Replace with operator" intention is not available anymore for non-operator functions
KT-11529 Highlighting range for unresolved annotation name does not include @ now
KT-11178 Don't show "Change type arguments" fix when there's nothing to change
KT-11789 Don't interpret annotations inside Markdown code blocks as KDoc tags
KT-11702 Fixed resolution of Kotlin beans with custom name
KT-11689 Fixed exception on attempt to navigate to Kotlin file from Spring notification balloon
KT-11725 Fixed renaming of injected SpEL references
KT-11720 Fixed renaming of Kotlin beans through SpEL references
KT-11719 Fixed renaming of Kotlin parameters references in XML files
KT-11736 Fixed searching of Java usages for @JvmStatic properties and @JvmStatic @JvmOverloads functions
KT-11862 Fixed bogus warnings about unresolved types in the Change Signature dialog
Fix several issues leading to exceptions: KT-11579, KT-11580, KT-11777, KT-11868, KT-11845, KT-11486
Fixed NoSuchFieldException in Kotlin module settings on IDEA Ultimate

Debugger

KT-11705 "Smart step into" no longer skips methods from subclasses
Debugger can now distinguish nested inline arguments
KT-11326 Support private classes in Evaluate Expression
KT-11455 Fix Evaluate Expression behavior for files with errors in sources
KT-10670 Fix Evaluate Expression behavior for inline functions with default parameters
KT-11380 Evaluate Expression now handles smart casts correctly
KT-10148 Do not suggest methods from outer context in "Smart step into"
Fix Evaluate Expression for expression created for array element
Complete private members from libraries in Evaluate Expression
KT-11578 Evaluate Expression: do not highlight completion variants from nullable receiver with grey
KT-6805 Convert Java expression to Kotlin when opening Evaluate Expression from Variables view
KT-11927 Fix "ambiguous import" error when invoking Evaluate Expression from Variables view for some field
KT-11831 Fix Evaluate Expression for values of raw types
Show error message when debug info for some local variable is corrupted
Avoid 1s delay in completion in debugger fields if session is not stopped on a breakpoint
Avoid cast to runtime type unavailable in current scope
Fix text with line breaks in popup with line breakpoint variants
Fix breakpoints inside inline functions in libraries sources
Allow breakpoints at catch clause declaration
KT-11848 Fix breakpoints inside generic crossinline lambda argument body
KT-11932 Fix Step Over for while loop condition

Java to Kotlin converter

Protected members used outside of inheritors are converted as public
Support conversion for annotation constructor calls
Place comments from the middle of the call to the end
Drop line breaks between operator arguments (except +, -, && and ||)
Add non-null assertions on call site for non-null parameters
Specify type for variables with anonymous type if they have write accesses
KT-11587 Fix conversion of static field accesses from other Java class
KT-6800 Quote $ symbols in converted strings
KT-11126 Convert annotations in annotations parameters correctly
KT-11600 Do not produce unresolved toArray calls for Java Collection#toArray(T[])
KT-11544 Fix conversion of uninitialized non-final field
KT-10604 Fix conversion of scratch files
KT-11543 Do not produce unnecessary casts of non-nullable expression to nullable type
KT-11160 Fix IDE freeze

Android

KT-7729 Add Android Lint checks for Kotlin (from Android Studio 1.5)
KT-11487 Fixed sequential build with kapt and stubs enabled when Kotlin source file was modified and no Java source files were modified
KT-11264 Action to create new activity in Kotlin
KT-11201 Do not ignore items with similar names in kapt
KT-11944 Rename Android Extensions imports when the layout file is renamed/deleted/added
KT-10321 Do not upcast ViewStub to View
KT-10841 Support @android:id/* IDs in Android Extensions

Maven

KT-2917, KT-11261 Maven archetype for new Kotlin projects

Gradle

KT-8487 Experimental support for incremental compilation with project property kotlin.incremental
KT-11350 Fixed a bug causing Java rebuild when both Java and Kotlin are up-to-date
KT-10507 Fix IllegalArgumentException "Missing extension point" on parallel builds
KT-10932 Prevent compile tasks from running when nothing changes
KT-11993 Fix NoSuchMethodError on access to internal members in production from tests (IDEA 2016+)