This plugin can add warnings or errors to your crate when using a numerically instable floating point expression.
Quick example of what you can get when compiling test/compile-fail/test.rs:
rust
test.rs:40:5: 40:18 warning: Numerically unstable expression, #[warn(herbie)] on by default
test.rs:40 (a/b + c) * b;
^~~~~~~~~~~~~
test.rs:40:5: 40:18 help: Try this
test.rs: (c * b) + a;
test.rs:67:5: 67:23 warning: Numerically unstable expression, #[warn(herbie)] on by default
test.rs:67 (a*a + b*b).sqrt();
^~~~~~~~~~~~~~~~~~
test.rs:67:5: 67:23 help: Try this
test.rs: a.hypot(b);
test.rs:155:5: 155:30 warning: Numerically unstable expression, #[warn(herbie)] on by default
test.rs:155 (a+b).sin() - (a+b).cos();
^~~~~~~~~~~~~~~~~~~~~~~~~
test.rs:155:5: 155:30 help: Try this
test.rs: (b.sin() * (a.sin() + a.cos())) - ((a.cos() - a.sin()) * b.cos());
As you can see, it will report numerically instable expressions, and suggest a (sometimes over-parenthesized) more stable correction.
This is a rustc plugin, to use it, you need a nightly Rust.
You need a database of possible corrections for this plugin to work. The
database format is the same as Herbie GHC Plugin (for Haskell)
from which this plugin is inspired so this file should work.
Just put it in the same directory you call cargo or rustc from.
Add in your Cargo.toml:
toml
[dependencies]
herbie-lint = "{{VERSION}}"
and in your crate:
```rust
```
See clippy's Usage section if you want to know more and if you want more Rust lints.