Kotlin 1.0.0 Beta 2

What's New

• Language
  • Single-instantiation inheritance for type parameters
  • More precise "smart cast impossible" (the reason is given now)
  • "Always null" warningadded
• Library
  • Ranges
    • Double and Float progressions are dropped
    • Byte and Short progressions are deprecated, the .. operator for bytes and shorts now returns IntRange
    • Range<T> renamed to ClosedRange<T> and its end property renamed to endInclusive
    • Progression<T> is deprecated in favor of concrete progression implementations instead: IntProgression, LongProrgession, CharProgression
    • start and end properties in progressions are renamed to first and last
  • kotlin.dom and kotlin.browser moved out as a separate library: kotlinx.dom
  • Strings/CharSequences
    • String utility extensions were generalized to take CharSequence where possible
  • Added
    • in-place reversing and sorting for MutableLists and Arrays
    • naturalOrder and reverseOrder comparators
    • mapNotNull, mapIndexedNotNull, filterIndexed
    • String.toByte()
  • Сhanged
    • Explicit type parameter specification for filterIsInstance now is required
  • Deprecated
    • Function.toGenerator
    • toLinkedList
  • Dropped
    • join, merge
    • Delegates.lazy
    • FileTreeWalk.filter, File.recurse, BufferedReader.lines and lineIterator
    • assert, check and require with non-lazy message argument
• IDE
  • Completion of java static members and members from objects on second Ctrl-Space
  • Intention action to import Java statics, object members or enum entries
  • Intention action to import all Java static members from the given class or enum entries from the given enum class
  • Completion in string templates works after "$name."
  • Debugger supports choosing where to put a breakpoint: inside or outside a single-lined lambda