add example

examples/custom_types.rs

@@ -0,0 +1,75 @@
+//! 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 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)
+                .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;
+            x.update();
+            x.calc(x.x)
+        ",
+    )?;
+
+    println!("result: {}", result); // prints 1085764
+
+    Ok(())
+}