feat(example): add js-hello-world example

examples/js-hello-world/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "js-hello-world"
+description = "an example rust->wasm crate"
+version = "0.1.0"
+authors = ["Ashley Williams <ashley666ashley@gmail.com>"]
+license = "WTFPL"
+repository = "https://github.com/ashleygwilliams/wasm-pack"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+wasm-bindgen = { git = 'https://github.com/alexcrichton/wasm-bindgen' }

examples/js-hello-world/src/lib.rs

@@ -0,0 +1,16 @@
+#![feature(proc_macro)]
+
+extern crate wasm_bindgen;
+
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen]
+extern {
+    fn alert(s: &str);
+}
+
+#[wasm_bindgen]
+#[no_mangle]
+pub extern fn greet(name: &str) {
+    alert(&format!("Hello, {}!", name));
+}