[DevoxxBE2013] The Unpuzzling Kotlin: Bringing Clarity to Your Code
Svetlana Isakova and Aleksei Sedunov, core Kotlin developers at JetBrains, dissect Java’s perplexing behaviors through Kotlin’s lens, affirming its mission for safer, concise JVM code. Svetlana, a language architect and Scala educator, pairs with Aleksei, IDE tooling specialist and Kotlin In-Depth author, to translate infamous Java Puzzlers—exposing casting pitfalls, expression ambiguities, and exception quirks—into Kotlin equivalents that eliminate obscurity.
Kotlin, they assert, rectifies Java’s design flaws via smart casts, safe calls, and extension functions, fostering intuitive industrial programming. Their analysis, rooted in real-world fixes, invites scrutiny at JetBrains’ booth.
Expressions and Control Structures
Svetlana contrasts Java’s operator precedence puzzles with Kotlin’s explicit parentheses, averting silent errors. She demos a chained assignment mishap, resolved in Kotlin by immutable vals.
Aleksei explores null safety: Kotlin’s ?. safe calls and !! assertions prevent NPEs, unlike Java’s unchecked casts.
Exception Handling and Resource Management
Java’s checked exceptions burden APIs, Aleksei notes; Kotlin’s unchecked model simplifies signatures. He illustrates try-with-resources emulation via use extensions, ensuring cleanup.
Svetlana highlights Elvis operator (?:) for concise defaults, streamlining null propagation absent in Java.
Objects, Classes, and Nullability
Kotlin’s data classes auto-generate equals/hashCode, eclipsing Java’s boilerplate. Aleksei demos sealed classes for exhaustive when branches, enhancing pattern matching.
Svetlana unveils nullable types: platform types from Java interop demand explicit handling, with smart casts post-checks yielding type safety.
Extensions and Practical Wisdom
Extensions augment classes without inheritance, Aleksei shows, adding string utilities seamlessly. He addresses puzzler avoidance: Kotlin’s design sidesteps most Java gotchas, though vigilance persists.
Svetlana fields queries on closures and extensions, affirming Kotlin’s simplicity for Java migrants.