Change hello world to Neon 0.2

_guides/hello-world.md

@@ -88,27 +88,27 @@ Now let's edit the Rust code to make use of the new dependency. First we have to
 extern crate num_cpus;
 ```
 
-Next we can replace the sample `hello` function that was generated by `neon new` with the function we actually want. Instead of returning a string, our function should return a JavaScript number. So we'll use the [`JsNumber::new()`](https://api.neon-bindings.com/neon/js/struct.jsnumber#method.new) API. Since `JsNumber` expects a Rust [`f64`](https://doc.rust-lang.org/std/primitive.f64.html) (i.e., a 64-bit floating-point number), and [`num_cpus::get()`](https://docs.rs/num_cpus/1.4.0/num_cpus/fn.get.html) returns a [`usize`](https://doc.rust-lang.org/std/primitive.usize.html) (i.e., a pointer-sized integer), we'll use Rust's `as` operator to cast to convert the integer to floating-point:
+Next we can replace the sample `hello` function that was generated by `neon new` with the function we actually want. Instead of returning a string, our function should return a JavaScript number. So we'll use the [`JsNumber::new()`](https://api.neon-bindings.com/neon/types/struct.jsnumber#method.new) API. Since `JsNumber` expects a Rust [`f64`](https://doc.rust-lang.org/std/primitive.f64.html) (i.e., a 64-bit floating-point number), and [`num_cpus::get()`](https://docs.rs/num_cpus/1.4.0/num_cpus/fn.get.html) returns a [`usize`](https://doc.rust-lang.org/std/primitive.usize.html) (i.e., a pointer-sized integer), we'll use Rust's `as` operator to cast to convert the integer to floating-point:
 
 ```rust
-use neon::js::JsNumber;
+use neon::prelude::*;
 
-fn threading_hint(call: Call) -> JsResult<JsNumber> {
-    Ok(JsNumber::new(call.scope, num_cpus::get() as f64))
+fn threading_hint(mut cx: FunctionContext) -> JsResult<JsNumber> {
+    Ok(JsNumber::new(&mut cx, num_cpus::get() as f64))
 }
 ```
 
 A few more things to note about this code:
 
   * The `call` argument to `threading_hint`: this contains information about the function call, such as the arguments and the value of `this`.
-  * The [`JsResult`](https://api.neon-bindings.com/neon/vm/type.jsresult) output type: this is a Rust [`Result`](https://doc.rust-lang.org/std/result/enum.Result.html) type that indicates whether the function returned (`Ok`) or threw a JavaScript exception (`Err`). You can learn more in the [Handling Errors](../handling-errors) guide. It also tracks the lifetime of the returned _handle_. You can read more about handles in the [Handles and Memory](../handles-and-memory/) guide.
+  * The [`JsResult`](https://api.neon-bindings.com/neon/result/type.jsresult) output type: this is a Rust [`Result`](https://doc.rust-lang.org/std/result/enum.Result.html) type that indicates whether the function returned (`Ok`) or threw a JavaScript exception (`Err`). You can learn more in the [Handling Errors](../handling-errors) guide. It also tracks the lifetime of the returned _handle_. You can read more about handles in the [Handles and Memory](../handles-and-memory/) guide.
   * The `call.scope` argument to `JsNumber::new()`: this tells the JavaScript garbage collector that we need to keep the value we allocate alive long enough to return it to the caller of `threading_hint`. You can learn more about memory management in the [Handles and Memory](../handles-and-memory/) guide.
 
 Finally, we'll modify the code that `neon new` created for us to set up the module exports with this function instead of the initial "hello world" function it created for us:
 
 ```rust
-register_module!(m, {
-    m.export("threading_hint", threading_hint)
+register_module!(mut cx, {
+    cx.export_function("threading_hint", threading_hint)
 });
 ```