Add @rsw dir

@rsw/hello/.gitignore

@@ -0,0 +1,6 @@
+/target
+**/*.rs.bk
+Cargo.lock
+bin/
+pkg/
+wasm-pack.log

@rsw/hello/Cargo.toml

@@ -0,0 +1,32 @@
+[package]
+name = "hello"
+version = "0.1.0"
+authors = ["Gregory Schier <gschier1990@gmail.com>"]
+edition = "2018"
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+
+[features]
+default = ["console_error_panic_hook"]
+
+[dependencies]
+wasm-bindgen = "0.2.63"
+
+# The `console_error_panic_hook` crate provides better debugging of panics by
+# logging them with `console.error`. This is great for development, but requires
+# all the `std::fmt` and `std::panicking` infrastructure, so isn't great for
+# code size when deploying.
+console_error_panic_hook = { version = "0.1.6", optional = true }
+
+# `wee_alloc` is a tiny allocator for wasm that is only ~1K in code size
+# compared to the default allocator's ~10K. It is slower than the default
+# allocator, however.
+wee_alloc = { version = "0.4.5", optional = true }
+
+[dev-dependencies]
+wasm-bindgen-test = "0.3.13"
+
+[profile.release]
+# Tell `rustc` to optimize for small code size.
+opt-level = "s"

@rsw/hello/src/lib.rs

@@ -0,0 +1,21 @@
+mod utils;
+
+use wasm_bindgen::prelude::*;
+
+// When the `wee_alloc` feature is enabled, use `wee_alloc` as the global allocator.
+#[cfg(feature = "wee_alloc")]
+#[global_allocator]
+static ALLOC: wee_alloc::WeeAlloc = wee_alloc::WeeAlloc::INIT;
+
+#[wasm_bindgen]
+extern {
+    fn alert(s: &str);
+
+    #[wasm_bindgen(js_namespace = console)]
+    fn log(s: &str);
+}
+
+#[wasm_bindgen]
+pub fn greet() {
+    log("Hello from Rust WASM!");
+}

@rsw/hello/src/utils.rs

@@ -0,0 +1,10 @@
+pub fn set_panic_hook() {
+    // When the `console_error_panic_hook` feature is enabled, we can call the
+    // `set_panic_hook` function at least once during initialization, and then
+    // we will get better error messages if our code ever panics.
+    //
+    // For more details see
+    // https://github.com/rustwasm/console_error_panic_hook#readme
+    #[cfg(feature = "console_error_panic_hook")]
+    console_error_panic_hook::set_once();
+}