Repace the Memo struct with ReadSignal

examples/todomvc/src/main.rs

@@ -340,7 +340,7 @@ pub fn List<G: Html>() -> View<G> {
 
             ul(class="todo-list") {
                 Keyed(
-                    iterable=*filtered_todos,
+                    iterable=filtered_todos,
                     view=|todo| view! {
                         Item(todo=todo)
                     },

packages/sycamore-core/src/view.rs

@@ -52,7 +52,7 @@ impl<G: GenericNode> View<G> {
     #[cfg_attr(debug_assertions, track_caller)]
     pub fn new_dyn(f: impl FnMut() -> View<G> + 'static) -> Self {
         Self {
-            inner: ViewType::Dyn(*create_memo(f).inner_signal()),
+            inner: ViewType::Dyn(create_memo(f)),
         }
     }
 

packages/sycamore-reactive/src/iter.rs

@@ -23,7 +23,7 @@ pub fn map_keyed<T, K, U: 'static>(
     list: impl Accessor<Vec<T>> + Clone + 'static,
     map_fn: impl Fn(T) -> U + 'static,
     key_fn: impl Fn(&T) -> K + 'static,
-) -> Memo<Vec<U>>
+) -> ReadSignal<Vec<U>>
 where
     T: PartialEq + Clone + 'static,
     K: Eq + Hash,
@@ -187,7 +187,7 @@ where
 pub fn map_indexed<T, U: 'static>(
     list: impl Accessor<Vec<T>> + Clone + 'static,
     map_fn: impl Fn(T) -> U + 'static,
-) -> Memo<Vec<U>>
+) -> ReadSignal<Vec<U>>
 where
     T: PartialEq + Clone + 'static,
     U: Clone,

packages/sycamore-reactive/src/memos.rs

@@ -1,54 +1,8 @@
 //! Memos (aka. eager derived signals).
 
 use std::cell::RefCell;
-use std::fmt::{self, Formatter};
-use std::ops::Deref;
 
-use crate::{create_empty_signal, create_signal, ReadSignal, Root, Signal};
-
-/// A memoized derived signal.
-///
-/// Usually created using [`create_memo`], [`create_selector`], and [`create_selector_with`].
-pub struct Memo<T: 'static> {
-    signal: Signal<T>,
-}
-
-impl<T> Memo<T> {
-    /// Get the inner [`Signal`] that is backing this memo.
-    ///
-    /// Be careful when using this! Normally, you should not be able to update a memo manually
-    /// because that is already being done automatically. However, you can use this to create a
-    /// "writable memo", one which can be both updated manually and automatically.
-    pub fn inner_signal(self) -> Signal<T> {
-        self.signal
-    }
-}
-
-impl<T> Deref for Memo<T> {
-    type Target = ReadSignal<T>;
-
-    fn deref(&self) -> &Self::Target {
-        &self.signal
-    }
-}
-
-impl<T> Clone for Memo<T> {
-    fn clone(&self) -> Self {
-        *self
-    }
-}
-impl<T> Copy for Memo<T> {}
-
-impl<T: fmt::Debug> fmt::Debug for Memo<T> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        self.with(|value| value.fmt(f))
-    }
-}
-impl<T: fmt::Display> fmt::Display for Memo<T> {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        self.with(|value| value.fmt(f))
-    }
-}
+use crate::{create_empty_signal, create_signal, ReadSignal, Root};
 
 /// Creates a memoized value from some signals.
 /// Unlike [`create_memo`], this function will not notify dependents of a
@@ -63,7 +17,7 @@ impl<T: fmt::Display> fmt::Display for Memo<T> {
 pub fn create_selector_with<T>(
     mut f: impl FnMut() -> T + 'static,
     mut eq: impl FnMut(&T, &T) -> bool + 'static,
-) -> Memo<T> {
+) -> ReadSignal<T> {
     let root = Root::global();
     let signal = create_empty_signal();
     let prev = root.current_node.replace(signal.id);
@@ -85,7 +39,7 @@ pub fn create_selector_with<T>(
         }
     }));
 
-    Memo { signal }
+    *signal
 }
 
 /// Creates a memoized computation from some signals.
@@ -131,7 +85,7 @@ pub fn create_selector_with<T>(
 /// # });
 /// ```
 #[cfg_attr(debug_assertions, track_caller)]
-pub fn create_memo<T>(f: impl FnMut() -> T + 'static) -> Memo<T> {
+pub fn create_memo<T>(f: impl FnMut() -> T + 'static) -> ReadSignal<T> {
     create_selector_with(f, |_, _| false)
 }
 
@@ -159,7 +113,7 @@ pub fn create_memo<T>(f: impl FnMut() -> T + 'static) -> Memo<T> {
 /// # });
 /// ```
 #[cfg_attr(debug_assertions, track_caller)]
-pub fn create_selector<T>(f: impl FnMut() -> T + 'static) -> Memo<T>
+pub fn create_selector<T>(f: impl FnMut() -> T + 'static) -> ReadSignal<T>
 where
     T: PartialEq,
 {
@@ -203,11 +157,11 @@ where
 pub fn create_reducer<T, Msg>(
     initial: T,
     reduce: impl FnMut(&T, Msg) -> T,
-) -> (Memo<T>, impl Fn(Msg)) {
+) -> (ReadSignal<T>, impl Fn(Msg)) {
     let reduce = RefCell::new(reduce);
     let signal = create_signal(initial);
     let dispatch = move |msg| signal.update(|value| *value = reduce.borrow_mut()(value, msg));
-    (Memo { signal }, dispatch)
+    (*signal, dispatch)
 }
 
 #[cfg(test)]

packages/sycamore-reactive/src/signals.rs

@@ -10,7 +10,7 @@ use std::ops::{AddAssign, Deref, DivAssign, MulAssign, RemAssign, SubAssign};
 use slotmap::Key;
 use smallvec::SmallVec;
 
-use crate::{create_memo, Mark, Memo, NodeHandle, NodeId, NodeState, ReactiveNode, Root};
+use crate::{create_memo, Mark, NodeHandle, NodeId, NodeState, ReactiveNode, Root};
 
 /// A read-only reactive value.
 ///
@@ -368,7 +368,7 @@ impl<T> Signal<T> {
     }
 
     #[cfg_attr(debug_assertions, track_caller)]
-    pub fn map<U>(self, mut f: impl FnMut(&T) -> U + 'static) -> Memo<U> {
+    pub fn map<U>(self, mut f: impl FnMut(&T) -> U + 'static) -> ReadSignal<U> {
         create_memo(move || self.with(&mut f))
     }
 

packages/sycamore-reactive/src/utils.rs

@@ -25,12 +25,6 @@ impl<T: Clone> Accessor<T> for ReadSignal<T> {
     }
 }
 
-impl<T: Clone> Accessor<T> for Memo<T> {
-    fn value(&self) -> T {
-        self.get_clone()
-    }
-}
-
 impl<T: Clone> Accessor<T> for T {
     fn value(&self) -> T {
         self.clone()
@@ -72,12 +66,6 @@ impl<T> Trackable for ReadSignal<T> {
     }
 }
 
-impl<T> Trackable for Memo<T> {
-    fn _track(&self) {
-        self.track();
-    }
-}
-
 macro_rules! impl_trackable_deps_for_tuple {
     ($($T:tt),*) => {
         paste::paste! {

packages/sycamore-router/src/router.rs

@@ -268,7 +268,7 @@ where
         }
     }));
     let route_signal = create_memo(move || pathname.with(|pathname| route.match_path(pathname)));
-    let view = view(*route_signal);
+    let view = view(route_signal);
     // Delegate click events from child <a> tags.
     if let Some(node) = view.as_node() {
         node.event(ev::click, integration.click_handler());

packages/tools/bench/benches/reactivity.rs

@@ -109,7 +109,7 @@ pub fn bench(c: &mut Criterion) {
         b.iter(|| {
             let d = create_root(|| {
                 let signal = create_signal(0);
-                let mut memos = Vec::<Memo<usize>>::new();
+                let mut memos = Vec::<ReadSignal<usize>>::new();
                 for _ in 0..1000usize {
                     if let Some(prev) = memos.last().copied() {
                         memos.push(create_memo(move || prev.get() + 1));