7 releases (3 stable)
1.0.2 | Jul 31, 2024 |
---|---|
1.0.1 | Jul 21, 2024 |
1.0.0 | Apr 22, 2024 |
0.11.2 | Apr 17, 2024 |
0.7.2 | Jan 11, 2024 |
32 downloads per month
250KB
6.5K
SLoC
RsCel is a CEL evaluator written in Rust. CEL is a google project that describes a turing-incomplete language that can be used to evaluate a user provdided expression. The language specification can be found here.
The design goals of this project were are as follows:
- Flexible enough to allow for a user to bend the spec if needed
- Sandbox'ed in such a way that only specific values can be bound
- Can be used as a wasm depenedency (or other ffi)
The basic example of how to use:
use rscel::{CelContext, BindContext, serde_json};
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()); // 3 converted 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 required 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).unwrap(), 7.into());
Dependencies
~8–15MB
~208K SLoC