LELelouBil·May 22, 2026Submission
Design Notes: Local Lifetimes for Kotlin
1 points · Open discussionKotlin
KEEP
Markdown2016–2026
Kotlin / KEEP
KEEP
Kotlin Evolution and Enhancement Process
18Distinct people
26Mentions
0Explicit recommenders
3.8KGitHub stars
What to know before exploring
What it is
Kotlin Evolution and Enhancement Process
GitHub
Where it is used
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What people are saying
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Also in these discussions
- arrow-kt/arrow-meta · linked in 2 of the same discussions
Mentioned in the same Hacker News threads. That is not proof they are substitutes.
This week on Hacker News
Nov 8–Nov 15 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/15/2026, 2:59:58 PM UTC.
No direct repository links were found in the indexed HN discussions over the past seven days. Older discussions are available below.
Mentions over time
HN mentions by year26 dated mentions
Observed mentions: 2016-04-20 17:18:24 UTC to 2026-05-22 00:03:58 UTC.
* An incomplete calendar period is marked with an outlined bar. Its count is not directly comparable with a full period.
Counts come from the repository’s dated source evidence. Index cutoff: 2026-11-02 08:16:59 UTC.
View mention counts and date ranges
| Period | Start (UTC) | End (exclusive, UTC) | Mentions | Submissions | Comments |
|---|---|---|---|---|---|
| 2016 | 2016-01-01 00:00:00 UTC | 2017-01-01 00:00:00 UTC | 2 | 1 | 1 |
| 2017 | 2017-01-01 00:00:00 UTC | 2018-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2018 | 2018-01-01 00:00:00 UTC | 2019-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2019 | 2019-01-01 00:00:00 UTC | 2020-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2020 | 2020-01-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 3 | 0 | 3 |
| 2021 | 2021-01-01 00:00:00 UTC | 2022-01-01 00:00:00 UTC | 3 | 1 | 2 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 3 | 1 | 2 |
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 3 | 0 | 3 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 2 | 0 | 2 |
| 2025 | 2025-01-01 00:00:00 UTC | 2026-01-01 00:00:00 UTC | 4 | 1 | 3 |
| 2026 (partial) | 2026-01-01 00:00:00 UTC | 2027-01-01 00:00:00 UTC | 4 | 1 | 3 |
What Hacker News says
4 sourcesKotlin itself has opted for inline union types to represent error results: https://github.com/Kotlin/KEEP/blob/main/proposals/KEEP-0441...
The existing Result type was a mistake to expose to users, IMO, as it encourages exceptions-as-control-flow and error type hierarchies which complicate error-handling even further. The convenient `runCatching` API also completely breaks reasonable error-handling on the JVM and Kotlin's structured concurrency (which happens to use exceptions-as-control-flow to signal coroutine cancellation).
Overall, Kotlin is moving away from higher-kinded types in the core language, not toward them.
In A perfectable programming languageThese remind me of checked exceptions in Java. Ironically, Kotlin removed checked exceptions because they tend to be annoying more than useful: there's no clear guideline to whether an exception is checked or unchecked, some functions like IO and reflection have them while others don't, they're verbose especially when closures are involved, and lots of functions simply catch and rethrow checked exceptions in unchecked exceptions.
Which leads me to: why is Kotlin implementing this in a non-JVM compatible way, instead of introducing checked exceptions with better language support? All the problems stated above can be avoided while keeping the core idea of checked exceptions, which seems to be the same as this proposal.
From the GitHub discussion, I see this comment (https://github.com/Kotlin/KEEP/discussions/447#discussioncom...):
> The dif
Read the rest
ference between checked exceptions from java and error unions in this proposal is how they are treated. Checked exceptions are exceptions and always interrupt the flow of execution. On the other hand, errors in this proposal are values and can be passed around as values or intentionally ignored or even aggregated enabling the ability to use them in async and awaitAll etc.
But is this a real difference or something that can be emulated mostly syntactically and no deeper than Kotlin's other features (e.g. nullables, getters and setters)? Checked exceptions are also values, and errors can be caught (then ignored or aggregated) but usually interrupt the flow of execution and get propagated like exceptions.
> what about interop with Java?
From the proposal discussion[0], the runtime representation on the JVM will just be `Object`.
[0]: https://github.com/Kotlin/KEEP/discussions/447#discussioncom...
In Kotlin's rich errors: Native, typed errors without exceptions