Write docs for subscriptions and reorganize a bit

native/src/lib.rs

@@ -34,7 +34,7 @@
 //! [`Windowed`]: renderer/trait.Windowed.html
 //! [`UserInterface`]: struct.UserInterface.html
 //! [renderer]: renderer/index.html
-//#![deny(missing_docs)]
+#![deny(missing_docs)]
 #![deny(missing_debug_implementations)]
 #![deny(unused_results)]
 #![deny(unsafe_code)]

native/src/subscription.rs

@@ -1,16 +1,42 @@
+//! Listen to external events in your application.
 use crate::{Event, Hasher};
 use futures::stream::BoxStream;
 
-pub type EventStream = BoxStream<'static, Event>;
-
+/// A request to listen to external events.
+///
+/// Besides performing async actions on demand with [`Command`], most
+/// applications also need to listen to external events passively.
+///
+/// A [`Subscription`] is normally provided to some runtime, like a [`Command`],
+/// and it will generate events as long as the user keeps requesting it.
+///
+/// For instance, you can use a [`Subscription`] to listen to a WebSocket
+/// connection, keyboard presses, mouse events, time ticks, etc.
+///
+/// [`Command`]: ../struct.Command.html
+/// [`Subscription`]: struct.Subscription.html
 pub type Subscription<T> = iced_core::Subscription<Hasher, EventStream, T>;
 
+/// A stream of runtime events.
+///
+/// It is the input of a [`Subscription`] in the native runtime.
+///
+/// [`Subscription`]: type.Subscription.html
+pub type EventStream = BoxStream<'static, Event>;
+
 pub use iced_core::subscription::Recipe;
 
 mod events;
 
 use events::Events;
 
+/// Returns a [`Subscription`] to all the runtime events.
+///
+/// This subscription will notify your application of any [`Event`] handled by
+/// the runtime.
+///
+/// [`Subscription`]: type.Subscription.html
+/// [`Event`]: ../enum.Event.html
 pub fn events() -> Subscription<Event> {
     Subscription::from_recipe(Events)
 }