TOtosh·Nov 13, 2022Submission
Datafrog: A lightweight Datalog engine in Rust
111 points · Open discussionrust-lang
datafrog
Rust2019–2026
rust-lang / datafrog
datafrog
A lightweight Datalog engine in Rust
8Distinct people
9Mentions
0Explicit recommenders
911GitHub stars
What to know before exploring
What it is
A lightweight Datalog engine in Rust
GitHub
Where it is used
No documented product use has been verified yet.
What people are saying
No recommendation phrase was found in the indexed comments.
No classified warning is attached to this page. Read the discussions before treating silence as approval.
Also in these discussions
- frankmcsherry/blog · linked in 2 of the same discussions
- rust-lang/polonius · 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, 12:01:02 AM 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 year9 dated mentions
Observed mentions: 2019-03-11 00:45:13 UTC to 2026-01-07 16:10:44 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 |
|---|---|---|---|---|---|
| 2019 | 2019-01-01 00:00:00 UTC | 2020-01-01 00:00:00 UTC | 2 | 0 | 2 |
| 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 | 2 | 0 | 2 |
| 2022 | 2022-01-01 00:00:00 UTC | 2023-01-01 00:00:00 UTC | 4 | 1 | 3 |
| 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 | 0 | 0 | 0 |
| 2026 (partial) | 2026-01-01 00:00:00 UTC | 2027-01-01 00:00:00 UTC | 1 | 0 | 1 |
What Hacker News says
4 sourcesFunny you say that, the Rust borrow checker tried to adopt differential-dataflow directly - the library behind this language - but Frank McSherry told them it's too complicated, let me build you an easier-to-use Datalog instead [blog]. So he built [datafrog] which is at the heart of the borrow checker today.
I'm not sure what the delta between Salsa and differential-dataflow is. My experience with differential-dataflow is that it's also galaxy brain.
[blog]: https://github.com/frankmcsherry/blog/blob/master/posts/2018...
[datafrog]: https://github.com/rust-lang/datafrog
In Differential Datalog: a programming language for incremental computationWhat is the difference with https://github.com/rust-lang/datafrog? It’s a Datalog engine written by Frank McSherry on top of differential dataflow, that’s used here also
In Differential Datalog: a programming language for incremental computationC++ is arguably the most complex programming language ever. There is not much to be gained by comparing against the supremum.
Take a look at the languages that rust was influenced by (https://en.wikipedia.org/wiki/Rust_(programming_language)) those aren't languages with straightforward compilation semantics.
There is a reason why rust has a datalog engine build into the compiler (https://github.com/rust-lang/datafrog). Which is imho totally rad and awesome, but really hard to fully form a mental model of without a spec.
In MiniRust