This repository contains proposals for the Kotlin Programming Language, including draft design notes and discussions for in-progress proposals as well as the design documentation on the changes that were already implemented.
The proposals themselves are colloquially referred to as KEEPs. They cover both the language itself and its standard library.
The implementation of the corresponding design enhancements usually lives in the Kotlin Source Code Repository.
1. The proposal is published.
Every new proposal gets a KEEP number (previous proposal number + 1).
The Markdown file is prefixed with the KEEP-xxxx- number and merged to the main branch.
2. Public KEEP review stage. Immediately after publishing the proposal, a new GitHub Discussion is opened. At this stage, we invite the community to read the proposal and share their opinion in the discussion.
3. The final decision on the proposal. The proposal is either Accepted, Rejected, or requires further refinement. For the specific proposals of your interest, it's also worth following an appropriate YouTrack issue which is usually mentioned in the KEEP document header.
The up-to-date status of each proposal must be recorded in the KEEP document header. Generally we use the following statuses:
Public discussionIn progressExperimental in 2.0.0Stable(discouraged, old status)Stable in 2.1.0DeclinedUnknown(discouraged, used for old proposals)Superseded by KEEP-xxxx
Every time a new KEEP proposal is published, we notify the community in the following channels:
- #language-proposals channel in Kotlin public Slack (get an invite here);
- GitHub Discussions RSS feed
We encourage you to follow one of the channels and share your opinion once a new proposal reaches its public review stage. The community feedback is crucial to the open philosophy of the Kotlin language enhancement process.
Some feature ideas that are being discussed for Kotlin represent important directions of potential enhancement but are not complete to call them design proposals. They still need to be discussed with the Kotlin community to gather use-cases for these features, their potential syntax, impact on existing Kotlin code, etc. They are called "design notes" and are stored in a separate notes directory.
If you have a use case that is not covered by the language or have a specific language enhancement in mind,
then, please, file a YouTrack issue in the Language Design subsystem.
While many popular enhancements and language design problems are already filed in
Kotlin YouTrack, your contribution to them is still very important:
- 👍 Vote for the issues you encounter in your work.
- 📝 Comment with the description of your specific use-cases.
Our practice of language design shows that contributing real-life use-cases is the most valuable piece of feedback from the Kotlin community.
- For in-progress KEEPs, please keep discussions in the corresponding GitHub Discussion thread.
- If you find problems with the text or have text correction for merged KEEPs, feel free to create a separate pull request with the proposed correction.
We don't expect Pull Requests that submit new KEEP proposals. Consider submitting a YouTrack ticket and describing your real-life use-cases as described above.