use js_sandbox_ios::{Script, AnyError};

fn main() -> Result<(), AnyError> {
    let js_code = "function sub(a, b) { return a - b; }";
    let mut script = Script::from_string(js_code)?;

    let result: i32 = script.call("sub", (7, 5))?;

    assert_eq!(result, 2);
    Ok(())
}

一个示例，它序列化一个 JSON 对象（Rust -> JS）并格式化一个字符串（JS -> Rust）

use js_sandbox_ios::{Script, AnyError};
use serde::Serialize;

#[derive(Serialize)]
struct Person {
    name: String,
    age: u8,
}

fn main() -> Result<(), AnyError> {
    let src = r#"
        function toString(person) {
            return "A person named " + person.name + " of age " + person.age;
        }"#;

    let mut script = Script::from_string(src)?;

    let person = Person { name: "Roger".to_string(), age: 42 };
    let result: String = script.call("toString", (person,))?;

    assert_eq!(result, "A person named Roger of age 42");
    Ok(())
}

加载 JS 文件

可以在运行时从任何 Path 加载 JavaScript 文件（例如第三方模组）。

如果您想将 UTF-8 编码的文件静态嵌入 Rust 可执行文件中，您还可以使用 std::include_str 宏。

use js_sandbox_ios::Script;

fn main() {
    // (1) at runtime:
    let mut script = Script::from_file("script.js").expect("load + init succeeds");

    // (2) at compile time:
    let code: &'static str = include_str!("script.js");
    let mut script = Script::from_string(code).expect("init succeeds");

    // use script as usual
}

在 JavaScript 中维护状态

可以初始化一个有状态的JS脚本，然后使用函数在一段时间内修改该状态。此示例在两次调用中追加一个字符串，然后在第三次调用中获取结果。

use js_sandbox_ios::{Script, AnyError};

fn main() -> Result<(), AnyError> {
    let src = r#"
        var total = '';
        function append(str) { total += str; }
        function get()       { return total; }"#;

    let mut script = Script::from_string(src)?;

    let _: () = script.call("append", ("hello",))?;
    let _: () = script.call("append", (" world",))?;
    let result: String = script.call("get", ())?;

    assert_eq!(result, "hello world");
    Ok(())
}

带超时调用脚本

JS代码可能包含长时间或永久运行的循环，这会阻塞Rust代码。可以在设置超时后终止JavaScript执行。

use js_sandbox_ios::{Script, JsError};

fn main() -> Result<(), JsError> {
    use std::time::Duration;
    let js_code = "function run_forever() { for(;;) {} }";
    let mut script = Script::from_string(js_code)?
        .with_timeout(Duration::from_millis(1000));

    let result: Result<String, JsError> = script.call("run_forever", ());

    assert_eq!(
        result.unwrap_err().to_string(),
        "Uncaught Error: execution terminated".to_string()
    );

    Ok(())
}