rhai/examples/custom_types.rs

94 lines
2.2 KiB
Rust

//! An example showing how to register a Rust type and methods/getters/setters using the `CustomType` trait.
#[cfg(feature = "no_object")]
fn main() {
panic!("This example does not run under 'no_object'.");
}
use rhai::{CustomType, Engine, EvalAltResult, TypeBuilder};
#[cfg(not(feature = "no_object"))]
fn main() -> Result<(), Box<EvalAltResult>> {
#[derive(Debug, Clone)]
struct TestStruct {
x: i64,
}
impl TestStruct {
pub fn new() -> Self {
Self { x: 1 }
}
pub fn update(&mut self) {
self.x += 1000;
}
pub fn calculate(&mut self, data: i64) -> i64 {
self.x * data
}
pub fn get_x(&mut self) -> i64 {
self.x
}
pub fn set_x(&mut self, value: i64) {
self.x = value;
}
}
impl IntoIterator for TestStruct {
type Item = i64;
type IntoIter = std::vec::IntoIter<Self::Item>;
fn into_iter(self) -> Self::IntoIter {
vec![self.x - 1, self.x, self.x + 1].into_iter()
}
}
impl CustomType for TestStruct {
fn build(mut builder: TypeBuilder<Self>) {
#[allow(deprecated)] // The TypeBuilder api is volatile.
builder
.with_name("TestStruct")
.with_fn("new_ts", Self::new)
.with_fn("update", Self::update)
.with_fn("calc", Self::calculate)
.is_iterable()
.with_get_set("x", Self::get_x, Self::set_x);
}
}
let mut engine = Engine::new();
engine.build_type::<TestStruct>();
#[cfg(feature = "metadata")]
{
println!("Functions registered:");
engine
.gen_fn_signatures(false)
.into_iter()
.for_each(|func| println!("{}", func));
println!();
}
let result = engine.eval::<i64>(
"
let x = new_ts();
x.x = 42;
for n in x {
x.x += n;
print(`n = ${n}, total = ${x.x}`);
}
x.update();
x.calc(x.x)
",
)?;
println!("result: {}", result); // prints 1085764
Ok(())
}