[ANN] dunai-0.11.0, dunai-test-0.11.0, bearriver-0.14.2

Dear all,

I’m really excited to announce the release of Dunai 0.11.0 and Bearriver 0.14.2!

Dunai is a reactive programming library structured around a notion of Monadic Stream Functions. Dunai can be used to implement other reactive and FRP frameworks on top, including Classic FRP and Arrowized FRP variants.

Dunai comes with:

  • bearriver: API-compatible implementation of Yampa. (The Bear River is a tributary to the Yampa river.)

  • dunai-test: QuickCheck-based temporal testing library that can be connected with the testing system haskell-titan.

See GitHub - ivanperez-keera/dunai: Classic FRP, Arrowized FRP, Reactive Programming, and Stream Programming, all via Monadic Stream Functions for details on Dunai’s features.

This release has addressed mainly styling issues. All library code now conforms to the main rules of the style guide we follow (which is publicly documented). We’ve also addressed other minor maintenance issues, like removal of unused code and updates to the README. In total, there have been more than 100 commits.

Special thanks go to Miao ZhiCheng (hellwolf on github) for a generous donation towards this release, and to Johannes Riecken (johannes-riecken on github) for a regular contribution to support the dunai and Yampa projects.

As always, dunai, dunai-test and bearriver are released in sync. For details, see:


You can explore the current versions at:


The github repo is located at:

What’s coming

This release comes exactly 2 months after the last release. The next release is planned for Jun 21, 2023.

There are several issues open that you can contribute to:

Following our roadmap, the pending changes remain as follows:

  • Benchmarks: Facilitate making sound, evidence-based decisions about suggested improvements to the implementation, by completing a series of benchmarks.


Our project is now seeking donations to help continue developing dunai, create new open source libraries, new material, and give talks.

Github will match the first 5K donated, so if you donate $1/month, github will donate the same amount.

No donation is too small. Any contribution will absolutely help.

See Sponsor @ivanperez-keera on GitHub Sponsors · GitHub for details.

If you can help, please come forward.

All the best,