A generic framework for on-demand, incrementalized computation. Inspired by adapton, glimmer, and rustc's query system.
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bors[bot] 4e9161e221
Merge #393
393: Allow "constant" tracked functions r=XFFXFF a=Skepfyr

Fixes #323.

This adds support for tracked functions with only a database as input,
that is, it does not take a salsa struct.

I'm not entirely convinced by this, it feels like it works somewhat accidentally and may be fragile to changes. I'm happy if this just get closed as I was mostly playing around to see how this worked.

This change has the odd side-effect of making this code work:
```rust
#[salsa::tracked]
fn tracked_fn(db: &dyn Db, unit: ()) -> u32 {
    44
}

```

Co-authored-by: Jack Rickard <jack.rickard@outlook.com>
2022-09-06 23:49:25 +00:00
.github/workflows Update test.yml 2022-08-24 18:45:53 +02:00
book fix typos 2022-09-02 22:44:41 +08:00
calc-example/calc Fix field visibilities in calc-example 2022-09-01 00:28:01 +03:00
components Replace () with Singleton Salsa struct 2022-09-06 00:34:00 +01:00
examples Remove ': salsa::Database' bound from two examples 2021-12-30 11:02:30 +00:00
salsa-2022-tests Replace () with Singleton Salsa struct 2022-09-06 00:34:00 +01:00
src Merge #381 2022-08-25 10:34:44 +00:00
tests Fix clippy issues 2022-08-24 18:45:53 +02:00
.dir-locals.el ask emacs to rustfmt on save 2018-09-28 11:26:57 -04:00
.gitignore Fix clippy issues 2022-08-24 18:45:53 +02:00
bors.toml Update book workflow 2021-09-28 22:03:05 +02:00
Cargo.toml test-env-log has been renamed to test-log 2022-08-22 11:00:47 +02:00
FAQ.md Update New Mexico state question 2020-06-26 15:48:29 +01:00
LICENSE-APACHE add readme, license, etc 2018-09-28 11:01:27 -04:00
LICENSE-MIT add readme, license, etc 2018-09-28 11:01:27 -04:00
README.md Update README.md 2022-08-26 21:50:21 +05:30
RELEASES.md highlight breaking changes 2019-08-15 08:08:00 -04:00
rustfmt.toml add empty/default rustfmt.toml 2022-08-22 19:19:22 +08:00

salsa

Test Book Released API docs Crates.io

A generic framework for on-demand, incrementalized computation.

Salsa Logo

Obligatory warning

Very much a WORK IN PROGRESS at this point. Ready for experimental use but expect frequent breaking changes.

Credits

This system is heavily inspired by adapton, glimmer, and rustc's query system. So credit goes to Eduard-Mihai Burtescu, Matthew Hammer, Yehuda Katz, and Michael Woerister.

Key idea

The key idea of salsa is that you define your program as a set of queries. Every query is used like function K -> V that maps from some key of type K to a value of type V. Queries come in two basic varieties:

  • Inputs: the base inputs to your system. You can change these whenever you like.
  • Functions: pure functions (no side effects) that transform your inputs into other values. The results of queries are memoized to avoid recomputing them a lot. When you make changes to the inputs, we'll figure out (fairly intelligently) when we can re-use these memoized values and when we have to recompute them.

Want to learn more?

To learn more about Salsa, try one of the following:

Getting in touch

The bulk of the discussion happens in the issues and pull requests, but we have a zulip chat as well.