new @delegate: use-site target for annotation (e.g. @delegate:Transient)
private top-level Kotlin classes should be compiled to package private java classes
unfinished multiline comment is an error
previously deprecated language constructs are now errors
type ckecking for use-site variance fixed
generic functions are compared for specificity through solving a constraint system
having multiple vararg parameters for one function is prohibited
super-calls to functions with default parameters are prohibited (pass all arguments explicitly)
implicit receiver behavior fixed
as-import removes original names if they were imported before
user code is not allowed in kotlin.** packages
type parameters of extension properties allowed to be indirectly used by the receiver type
members of private classes can-not be accessed from non-private inline functions
diagnostics for multiple conflicting Kotlin runtime versions in classpath
some functions have been made inline
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.
library code rearranged into more granular packages (no source changes should be required)
associate and associateBy are added to aid construction of maps
associate and associateBy (instead of toMap/toMapBy)
groupBy with key- and value-selector functions
Map.getOrElse() and Map.getOrPut() now treat keys associated with null values as missing.
Map.getOrImplicitDefault() has been made internal
mutableListOf, mutableSetOf, mutableMapOf added to construct mutable collections. linkedListOf is deprecated
toMutableList added instead of toArrayList. The latter is deprecated
kotlin.system.exitProcess instead of System.exit
File.deleteRecursively only returns false in case of incomplete deletion
File.copyRecursively allows overwriting by specifying argument overwrite=true
changed File.copyTo behavior to be like Files.copy from JDK8.
more specific return type for File.inputStream, File.outputStream, String.byteInputStream.
IO utility functions taking charset name as a string are deprecated, use ones with Charset parameter.
File.useLines and Reader.readLines are introduced
File.(buffered)reader/writer now return less specific InputStreamReader/OutputStreamWriter and use UTF-8 encoding by default
Sequence and Iterable SAM constructor-like functions
Comparator- and comparison-related functions are moved to kotlin.comparisons package (not imported by default)
new properties in MatchResult: groupValues and destructured — provided for easier handling of regular expression match results
Lazy is now an interface open for implementation
kotlin.system.measureTimeNano renamed to measureNanoTime.
plusElement and minusElement functions as a synonyms for list + element and list - element.
kotlin.test.assertFailsWith with Class<T> parameter is deprecated, use an overload with KClass<T>.
toLinkedMap is deprecated.
UTF_32 charset properties added to Chatsets
Intention to replace iteration over map entries with a loop using a destructuring declaration
Inspection and quickfix to cleanup redundant visibility modifiers
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
Action to generate the toString() method
Support for implementing members by primary constructor parameters
Parameter info popup works for showing type parameters
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
