Add rust doc to the crate

src/lib.rs

@@ -15,10 +15,16 @@ use std::{marker::PhantomData, rc::Rc};
 
 use sycamore::prelude::*;
 
+/// Trait that maps a message and an original state value to a new value.
+/// Implementors of this trait can implement all of their state management
+/// logic in one place.
 pub trait MessageMapper<Msg, Out> {
     fn map(&self, msg: Msg, original: &ReadSignal<Out>) -> Out;
 }
 
+/// Provides the necessary wiring for a centralized state handling
+/// mechanism. The API guides you along handling the lifetimes properly
+/// as well as registering all the state management logic in one place.
 pub struct Handler<'ctx, D, T, Msg>
 where
     D: MessageMapper<Msg, T>,
@@ -32,6 +38,9 @@ impl<'ctx, D, T, Msg> Handler<'ctx, D, T, Msg>
 where
     D: MessageMapper<Msg, T>,
 {
+    /// Constructs a new Handler with a lifetime anchored to the provided Scope.
+    /// You will usually construct this in your top level scope and then
+    /// pass the handlers down into your components.
     pub fn new(cx: Scope<'ctx>, initial: T, dispatcher: D) -> &'ctx Self {
         let signal = create_signal(cx, initial);
         let dispatcher = create_ref(cx, dispatcher);
@@ -49,10 +58,13 @@ where
         self.signal.set(self.dispatcher.map(msg, self.signal))
     }
 
+    /// Provides a ReadSignal handle for the contained Signal implementation.
     pub fn read_signal(&'ctx self) -> &'ctx ReadSignal<T> {
         self.signal
     }
 
+    /// Binds a triggering signal and associated message mapping function as
+    /// a state update for this Handler instance.
     pub fn bind_trigger<F, Val>(
         &'ctx self,
         cx: Scope<'ctx>,
@@ -64,6 +76,9 @@ where
         create_effect(cx, move || self.dispatch(message_fn(trigger.get())));
     }
 
+    /// Helper method to get a memoized value derived from the contained
+    /// state for this Handler. The provided handler only notifies subscribers
+    /// If the state has actually been updated.
     pub fn get_selector<F, Val>(
         &'ctx self,
         cx: Scope<'ctx>,