Expand description
A JEXL evaluator written in Rust This crate depends on a JEXL parser crate that handles all the parsing and is a part of the same workspace. JEXL is an expression language used by Mozilla, you can find more information here: https://github.com/mozilla/mozjexl
§How to use
The access point for this crate is the eval
functions of the Evaluator Struct
You can use the eval
function directly to evaluate standalone statements
For example:
use jexl_eval::Evaluator;
use serde_json::json as value;
let evaluator = Evaluator::new();
assert_eq!(evaluator.eval("'Hello ' + 'World'").unwrap(), value!("Hello World"));
You can also run the statements against a context using the eval_in_context
function
The context can be any type that implements the serde::Serializable
trait
and the function will return errors if the statement doesn’t match the context
For example:
use jexl_eval::Evaluator;
use serde_json::json as value;
let context = value!({"a": {"b": 2.0}});
let evaluator = Evaluator::new();
assert_eq!(evaluator.eval_in_context("a.b", context).unwrap(), value!(2.0));
Modules§
Structs§
Type Aliases§
- Transform
Fn - TransformFn represents an arbitrary transform function
Transform functions take an arbitrary number of
serde_json::Value
to represent their arguments and return aserde_json::Value
. the transform function itself is responsible for checking if the format and number of the arguments is correct