rscel

Crates.iorscel
lib.rsrscel
version1.0.7
created_at2024-01-11 05:35:13.197321+00
updated_at2025-11-15 16:54:33.959061+00
descriptionCel interpreter in rust
homepage
repository
max_upload_size
id1095884
size364,330
(1BADragon)

documentation

README

rscel

RsCel is a CEL evaluator written in Rust. CEL is a Turing-incomplete language that can be used to evaluate a user-provided expression. The language specification can be found here.

The design goals of this project are as follows:

  • Isolated execution of CEL expressions
  • Flexible enough to allow for a user to bend the spec if needed
  • Can be used as a WASM depenedency (or other FFI)

The basic example of how to use:

use rscel::{CelContext, BindContext};

let mut ctx = CelContext::new();
let mut exec_ctx = BindContext::new();

ctx.add_program_str("main", "foo + 3").unwrap();
exec_ctx.bind_param("foo", 3.into()); // convert to CelValue

let res = ctx.exec("main", &exec_ctx).unwrap(); // CelValue::Int(6)
assert_eq!(res, 6.into());

As of 0.10.0, binding protobuf messages from the protobuf crate is now available! Given the following protobuf message:


message Point {
  int32 x = 1;
  int32 y = 2;
}
  

The following code can be used to evaluate a CEL expression on a Point message:

use rscel::{CelContext, BindContext};

// currently rscel requires protobuf messages to be in a box 
let p = Box::new(protos::Point::new());
p.x = 4;
p.y = 5;

let mut ctx = CelContext::new();
let mut exec_ctx = BindContext::new();

ctx.add_program_str("main", "p.x + 3").unwrap();
exec_ctx.bind_protobuf_msg("p", p);

assert_eq!(ctx.exec("main", &exec_ctx), 7.into());
  

Build status: Rust

Commit count: 0

cargo fmt