Add a smorgasboard example

examples/smorgasboard/src/lib.rs

@@ -0,0 +1,79 @@
+#![feature(proc_macro)]
+
+extern crate wasm_bindgen;
+
+use wasm_bindgen::prelude::*;
+
+// Strings can both be passed in and received
+#[wasm_bindgen]
+#[no_mangle]
+pub extern fn concat(a: &str, b: &str) -> String {
+    let mut a = a.to_string();
+    a.push_str(b);
+    return a
+}
+
+// A struct will show up as a class on the JS side of things
+#[wasm_bindgen]
+pub struct Foo {
+    contents: u32,
+}
+
+#[wasm_bindgen]
+impl Foo {
+    pub fn new() -> Foo {
+        Foo { contents: 0 }
+    }
+
+    // Methods can be defined with `&mut self` or `&self`, and arguments you
+    // can pass to a normal free function also all work in methods.
+    pub fn add(&mut self, amt: u32) -> u32 {
+        self.contents += amt;
+        return self.contents
+    }
+
+    // You can also take a limited set of references to other types as well.
+    pub fn add_other(&mut self, bar: &Bar) {
+        self.contents += bar.contents;
+    }
+
+    // Ownership can work too!
+    pub fn consume_other(&mut self, bar: Bar) {
+        self.contents += bar.contents;
+    }
+}
+
+#[wasm_bindgen]
+pub struct Bar {
+    contents: u32,
+    opaque: JsValue, // defined in `wasm_bindgen`, imported via prelude
+}
+
+#[wasm_bindgen(module = "./awesome")] // what ES6 module to import from
+extern {
+    fn bar_on_reset(to: &str, opaque: &JsValue);
+
+    // We can import classes and annotate functionality on those classes as well
+    type Awesome;
+    #[wasm_bindgen(constructor)]
+    fn new() -> Awesome;
+    #[wasm_bindgen(method)]
+    fn get_internal(this: &Awesome) -> u32;
+}
+
+#[wasm_bindgen]
+impl Bar {
+    pub fn from_str(s: &str, opaque: JsValue) -> Bar {
+        let contents = s.parse().unwrap_or_else(|_| {
+            Awesome::new().get_internal()
+        });
+        Bar { contents, opaque }
+    }
+
+    pub fn reset(&mut self, s: &str) {
+        if let Ok(n) = s.parse() {
+            bar_on_reset(s, &self.opaque);
+            self.contents = n;
+        }
+    }
+}