What's new in Kotlin 1.5.30

Kotlin 1.5.30 brings in a number of interesting updates including:

- Sealed when statements
- Support for suspend functions as supertypes
- Type inference for recursive generic types
- JS IR compiler reaches Beta
- Native support for Apple silicon

#Kotlin #Release

0:00 Introduction
0:51 Overview of the changes
1:45 Requiring opt-in for implicit usage of experimental API
4:04 Changes in using opt-in requirement annotations with different targets
4:53 Improvements to type inference on recursive generic types
6:31 Eliminating builder inference restrictions
7:37 Sealed 'when' statement
8:41 Suspend function as super type
9:21 Improvements to handling nullability annotations
10:26 Instantiation of annotation classes
11:20 Apple silicon support
11:57 Interoperability with Swift 5.5 async/await
12:46 Improved Swift/Objective-C mapping for objects
13:10 JavaScript IR compiler backend goes Beta
13:36 Kotlin/JS inspection pack
14:06 JavaScript source maps generation for Kotlin/JS IR backend
15:55 Parsing Duration from String
16:46 Matching with Regex at a particular position
17:26 Splitting to a sequence with Regex
17:46 Have a nice Kotlin!

[rustammusin]

I had a task on an interview when they wanted me to split a string by a specific character lazily, now it can be easily done, just wow!

[evgenyegorov]

Learned about recursive generic builder pattern from this update :)

[yaadata]

Thinking how handy opt in would be when developing libraries and releasing alpha/beta features and real world experimentation without introducing breaking changes to the stable components. Nice!

[jondo]

The compiler error on when will be nice. Find bugs as early as possible, make the usage of when as safe as possible, when is very powerful having something powerful and safe is nice.

[erik-tx]

Thanks for providing these updates, I enjoy them a lot, but it's a shame the audio is still off, just like last video. Good luck with Kotlin!

[maksimmuruev]

> Task :app:compileKotlin FAILED
e: Unknown JVM target version: 17
Supported versions: 1.6, 1.8, 9, 10, 11, 12, 13, 14, 15, 16
When we can expect 17 support? kt ver 1.5.31

[danuverah]

I'm afraid that @RequiresOptin will be used for legalese stuff ... Could you not just put an enum in there with e.g. ALPHA and BETA, possibly with a data to indicate when updates are expected?

[mehmetburakakgun]

I think the last example prints: "brown&blue" and "ping&green", right?

[ErikHuizinga]

matchesAt sounds like it would return multiple matches. Not sure if there's a use case for that, because you're specifying an index to match at. Why not isMatchAt?