PHphaedrus·Mar 14, 2025
See also: https://github.com/nucleic/kiwi
In The Cassowary Linear Arithmetic Constraint Solving Algorithm [pdf] (2002)nucleic
kiwi
C++2015–2025
nucleic / kiwi
kiwi
Efficient C++ implementation of the Cassowary constraint solving algorithm
3Distinct people
4Mentions
0Explicit recommenders
785GitHub stars
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What it is
Efficient C++ implementation of the Cassowary constraint solving algorithm
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This week on Hacker News
Nov 7–Nov 14 UTC · Direct repository links and separately labeled related project stories. Indexed through 11/14/2026, 3:56:07 PM UTC.
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HN mentions by year4 dated mentions
Observed mentions: 2015-07-07 08:50:21 UTC to 2025-03-14 16:33:12 UTC.
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 |
|---|---|---|---|---|---|
| 2015 | 2015-01-01 00:00:00 UTC | 2016-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2016 | 2016-01-01 00:00:00 UTC | 2017-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 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 | 0 | 0 | 0 |
| 2019 | 2019-01-01 00:00:00 UTC | 2020-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2020 | 2020-01-01 00:00:00 UTC | 2021-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2021 | 2021-01-01 00:00:00 UTC | 2022-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 1 | 0 | 1 |
| 2023 | 2023-01-01 00:00:00 UTC | 2024-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2024 | 2024-01-01 00:00:00 UTC | 2025-01-01 00:00:00 UTC | 0 | 0 | 0 |
| 2025 | 2025-01-01 00:00:00 UTC | 2026-01-01 00:00:00 UTC | 1 | 0 | 1 |
What Hacker News says
4 sourcesYou probably won't like Kiwi[0] then, either.
[0] https://github.com/nucleic/kiwi
In Cassowary – Run Windows Apps on Linux using a VM as if they were native appsIf any of the Luau devs are watching this, please flesh out the metamethods. I'd switch almost everything to Luau if they were improved.
They're the biggest PITA right now as designed in PUC-Rio, and I see that while you've improved upon __eq, other metamethods are still lacking.
In PUC-Rio, boolean equality operators FORCE a boolean result, regardless of what you return. Ideally they would allow returning any result type, which then can be coerced to boolean later (e.g. by an `if` statement), just like the arithmetic operators do.
Further, `__neq`, `__ge` and `__gt` do not exist. They should.
The lack of a proper metamethod design means that binding to e.g. Kiwi[0] is impossible without some incredibly fugly hacks. It has been a long-standing annoyance with Lua in an otherwise beautiful little scripting language (that I use frequently).
Read the rest
This looks quite nice - lots of attempts in this space but nothing that attempts to match Lua to this degree.
[0] https://github.com/nucleic/kiwi
You should use this nowadays: https://github.com/nucleic/kiwi
Kiwi is an implementation of the algorithm based on the seminal Cassowary paper.
It is not a refactoring of the original C++ solver. Kiwi has been designed from the ground up to be lightweight and fast. Kiwi ranges from 10x to 500x faster than the original Cassowary solver with typical use cases gaining a 40x improvement. Memory savings are consistently > 5x.
In Cassowary – A Constraint Solving Toolkit