This work is a derivative of this repository: https://github.com/fengcen/eval
The aforementioned repository has been abandoned, hence the reason for this repository/crate.
Supported operators: ! != "" '' () [] , > < >= <= ==
+ - * / % && || n..m.
Built-in functions: min() max() len() is_empty() array().
- Template engine
- ...
Add dependency to Cargo.toml
[dependencies]
resolver = "^0.1"In your main.rs or lib.rs:
extern crate resolver;You can do mathematical calculations with supported operators:
use resolver::{eval, to_value};
assert_eq!(eval("1 + 2 + 3"), Ok(to_value(6)));
assert_eq!(eval("2 * 2 + 3"), Ok(to_value(7)));
assert_eq!(eval("2 / 2 + 3"), Ok(to_value(4.0)));
assert_eq!(eval("2 / 2 + 3 / 3"), Ok(to_value(2.0)));You can eval with context:
use resolver::{Expr, to_value};
assert_eq!(Expr::new("foo == bar")
.value("foo", true)
.value("bar", true)
.exec(),
Ok(to_value(true)));You can access data like javascript by using . and []. [] supports expression.
use resolver::{Expr, to_value};
use std::collections::HashMap;
let mut object = HashMap::new();
object.insert("foos", vec!["Hello", "world", "!"]);
assert_eq!(Expr::new("object.foos[1-1] == 'Hello'")
.value("object", object)
.exec(),
Ok(to_value(true)));You can eval with function:
use resolver::{Expr, to_value};
assert_eq!(Expr::new("say_hello()")
.function("say_hello", |_| Ok(to_value("Hello world!")))
.exec(),
Ok(to_value("Hello world!")));You can create an array with array():
use resolver::{eval, to_value};
assert_eq!(eval("array(1, 2, 3, 4, 5)"), Ok(to_value(vec![1, 2, 3, 4, 5])));You can create an integer array with n..m:
use resolver::{eval, to_value};
assert_eq!(eval("0..5"), Ok(to_value(vec![0, 1, 2, 3, 4])));resolver is under the terms of the GPL-3.0-only license.
See LICENSE for details.