feat: Oco (Owned Clones Once) smart pointer (#1480)

.gitignore

@@ -9,3 +9,5 @@ Cargo.lock
 .idea
 .direnv
 .envrc
+
+.vscode

leptos/src/additional_attributes.rs

@@ -1,10 +1,11 @@
 use crate::TextProp;
+use std::rc::Rc;
 
 /// A collection of additional HTML attributes to be applied to an element,
 /// each of which may or may not be reactive.
-#[derive(Default, Clone)]
+#[derive(Clone)]
 #[repr(transparent)]
-pub struct AdditionalAttributes(pub(crate) Vec<(String, TextProp)>);
+pub struct AdditionalAttributes(pub(crate) Rc<[(String, TextProp)]>);
 
 impl<I, T, U> From<I> for AdditionalAttributes
 where
@@ -22,6 +23,12 @@ where
     }
 }
 
+impl Default for AdditionalAttributes {
+    fn default() -> Self {
+        Self([].into_iter().collect())
+    }
+}
+
 /// Iterator over additional HTML attributes.
 #[repr(transparent)]
 pub struct AdditionalAttributesIter<'a>(

leptos/src/text_prop.rs

@@ -1,14 +1,15 @@
+use leptos_reactive::Oco;
 use std::{fmt::Debug, rc::Rc};
 
 /// Describes a value that is either a static or a reactive string, i.e.,
 /// a [`String`], a [`&str`], or a reactive `Fn() -> String`.
 #[derive(Clone)]
-pub struct TextProp(Rc<dyn Fn() -> String>);
+pub struct TextProp(Rc<dyn Fn() -> Oco<'static, str>>);
 
 impl TextProp {
     /// Accesses the current value of the property.
     #[inline(always)]
-    pub fn get(&self) -> String {
+    pub fn get(&self) -> Oco<'static, str> {
         (self.0)()
     }
 }
@@ -21,23 +22,38 @@ impl Debug for TextProp {
 
 impl From<String> for TextProp {
     fn from(s: String) -> Self {
+        let s: Oco<'_, str> = Oco::Counted(Rc::from(s));
         TextProp(Rc::new(move || s.clone()))
     }
 }
 
-impl From<&str> for TextProp {
-    fn from(s: &str) -> Self {
-        let s = s.to_string();
+impl From<&'static str> for TextProp {
+    fn from(s: &'static str) -> Self {
+        let s: Oco<'_, str> = s.into();
         TextProp(Rc::new(move || s.clone()))
     }
 }
 
-impl<F> From<F> for TextProp
+impl From<Rc<str>> for TextProp {
+    fn from(s: Rc<str>) -> Self {
+        let s: Oco<'_, str> = s.into();
+        TextProp(Rc::new(move || s.clone()))
+    }
+}
+
+impl From<Oco<'static, str>> for TextProp {
+    fn from(s: Oco<'static, str>) -> Self {
+        TextProp(Rc::new(move || s.clone()))
+    }
+}
+
+impl<F, S> From<F> for TextProp
 where
-    F: Fn() -> String + 'static,
+    F: Fn() -> S + 'static,
+    S: Into<Oco<'static, str>>,
 {
     #[inline(always)]
     fn from(s: F) -> Self {
-        TextProp(Rc::new(s))
+        TextProp(Rc::new(move || s().into()))
     }
 }

leptos_dom/src/components.rs

@@ -14,12 +14,12 @@ pub use dyn_child::*;
 pub use each::*;
 pub use errors::*;
 pub use fragment::*;
-use leptos_reactive::untrack_with_diagnostics;
+use leptos_reactive::{untrack_with_diagnostics, Oco};
 #[cfg(all(target_arch = "wasm32", feature = "web"))]
 use once_cell::unsync::OnceCell;
+use std::fmt;
 #[cfg(all(target_arch = "wasm32", feature = "web"))]
 use std::rc::Rc;
-use std::{borrow::Cow, fmt};
 pub use unit::*;
 #[cfg(all(target_arch = "wasm32", feature = "web"))]
 use wasm_bindgen::JsCast;
@@ -55,7 +55,7 @@ pub struct ComponentRepr {
     #[cfg(all(target_arch = "wasm32", feature = "web"))]
     mounted: Rc<OnceCell<()>>,
     #[cfg(any(debug_assertions, feature = "ssr"))]
-    pub(crate) name: Cow<'static, str>,
+    pub(crate) name: Oco<'static, str>,
     #[cfg(debug_assertions)]
     _opening: Comment,
     /// The children of the component.
@@ -163,24 +163,24 @@ impl IntoView for ComponentRepr {
 impl ComponentRepr {
     /// Creates a new [`Component`].
     #[inline(always)]
-    pub fn new(name: impl Into<Cow<'static, str>>) -> Self {
+    pub fn new(name: impl Into<Oco<'static, str>>) -> Self {
         Self::new_with_id_concrete(name.into(), HydrationCtx::id())
     }
 
     /// Creates a new [`Component`] with the given hydration ID.
     #[inline(always)]
     pub fn new_with_id(
-        name: impl Into<Cow<'static, str>>,
+        name: impl Into<Oco<'static, str>>,
         id: HydrationKey,
     ) -> Self {
         Self::new_with_id_concrete(name.into(), id)
     }
 
-    fn new_with_id_concrete(name: Cow<'static, str>, id: HydrationKey) -> Self {
+    fn new_with_id_concrete(name: Oco<'static, str>, id: HydrationKey) -> Self {
         let markers = (
-            Comment::new(Cow::Owned(format!("</{name}>")), &id, true),
+            Comment::new(format!("</{name}>"), &id, true),
             #[cfg(debug_assertions)]
-            Comment::new(Cow::Owned(format!("<{name}>")), &id, false),
+            Comment::new(format!("<{name}>"), &id, false),
         );
 
         #[cfg(all(target_arch = "wasm32", feature = "web"))]
@@ -236,7 +236,7 @@ where
     V: IntoView,
 {
     id: HydrationKey,
-    name: Cow<'static, str>,
+    name: Oco<'static, str>,
     children_fn: F,
 }
 
@@ -246,7 +246,7 @@ where
     V: IntoView,
 {
     /// Creates a new component.
-    pub fn new(name: impl Into<Cow<'static, str>>, f: F) -> Self {
+    pub fn new(name: impl Into<Oco<'static, str>>, f: F) -> Self {
         Self {
             id: HydrationCtx::id(),
             name: name.into(),

leptos_dom/src/components/dyn_child.rs

@@ -3,7 +3,7 @@ use crate::{
     Comment, IntoView, View,
 };
 use cfg_if::cfg_if;
-use std::{borrow::Cow, cell::RefCell, fmt, ops::Deref, rc::Rc};
+use std::{cell::RefCell, fmt, ops::Deref, rc::Rc};
 cfg_if! {
   if #[cfg(all(target_arch = "wasm32", feature = "web"))] {
     use crate::{mount_child, prepare_to_move, unmount_child, MountKind, Mountable, Text};
@@ -83,9 +83,9 @@ impl Mountable for DynChildRepr {
 impl DynChildRepr {
     fn new_with_id(id: HydrationKey) -> Self {
         let markers = (
-            Comment::new(Cow::Borrowed("</DynChild>"), &id, true),
+            Comment::new("</DynChild>", &id, true),
             #[cfg(debug_assertions)]
-            Comment::new(Cow::Borrowed("<DynChild>"), &id, false),
+            Comment::new("<DynChild>", &id, false),
         );
 
         #[cfg(all(target_arch = "wasm32", feature = "web"))]

leptos_dom/src/components/each.rs

@@ -2,7 +2,7 @@
 use crate::hydration::HydrationKey;
 use crate::{hydration::HydrationCtx, Comment, CoreComponent, IntoView, View};
 use leptos_reactive::{as_child_of_current_owner, Disposer};
-use std::{borrow::Cow, cell::RefCell, fmt, hash::Hash, ops::Deref, rc::Rc};
+use std::{cell::RefCell, fmt, hash::Hash, ops::Deref, rc::Rc};
 #[cfg(all(target_arch = "wasm32", feature = "web"))]
 use web::*;
 
@@ -79,9 +79,9 @@ impl Default for EachRepr {
         let id = HydrationCtx::id();
 
         let markers = (
-            Comment::new(Cow::Borrowed("</Each>"), &id, true),
+            Comment::new("</Each>", &id, true),
             #[cfg(debug_assertions)]
-            Comment::new(Cow::Borrowed("<Each>"), &id, false),
+            Comment::new("<Each>", &id, false),
         );
 
         #[cfg(all(target_arch = "wasm32", feature = "web"))]
@@ -224,13 +224,13 @@ impl EachItem {
 
         let markers = (
             if needs_closing {
-                Some(Comment::new(Cow::Borrowed("</EachItem>"), &id, true))
+                Some(Comment::new("</EachItem>", &id, true))
             } else {
                 None
             },
             #[cfg(debug_assertions)]
             if needs_closing {
-                Some(Comment::new(Cow::Borrowed("<EachItem>"), &id, false))
+                Some(Comment::new("<EachItem>", &id, false))
             } else {
                 None
             },

leptos_dom/src/events.rs

@@ -1,14 +1,15 @@
 pub mod typed;
 
-use std::{borrow::Cow, cell::RefCell, collections::HashSet};
+use leptos_reactive::Oco;
+use std::{cell::RefCell, collections::HashSet};
 #[cfg(all(target_arch = "wasm32", feature = "web"))]
 use wasm_bindgen::{
     convert::FromWasmAbi, intern, prelude::Closure, JsCast, JsValue,
     UnwrapThrowExt,
 };
 
 thread_local! {
-    pub(crate) static GLOBAL_EVENTS: RefCell<HashSet<Cow<'static, str>>> = RefCell::new(HashSet::new());
+    pub(crate) static GLOBAL_EVENTS: RefCell<HashSet<Oco<'static, str>>> = RefCell::new(HashSet::new());
 }
 
 // Used in template macro
@@ -47,8 +48,8 @@ pub fn add_event_helper<E: crate::ev::EventDescriptor + 'static>(
 #[cfg(all(target_arch = "wasm32", feature = "web"))]
 pub fn add_event_listener<E>(
     target: &web_sys::Element,
-    key: Cow<'static, str>,
-    event_name: Cow<'static, str>,
+    key: Oco<'static, str>,
+    event_name: Oco<'static, str>,
     #[cfg(debug_assertions)] mut cb: Box<dyn FnMut(E)>,
     #[cfg(not(debug_assertions))] cb: Box<dyn FnMut(E)>,
     options: &Option<web_sys::AddEventListenerOptions>,
@@ -115,7 +116,7 @@ pub(crate) fn add_event_listener_undelegated<E>(
 #[cfg(all(target_arch = "wasm32", feature = "web"))]
 pub(crate) fn add_delegated_event_listener(
     key: &str,
-    event_name: Cow<'static, str>,
+    event_name: Oco<'static, str>,
     options: &Option<web_sys::AddEventListenerOptions>,
 ) {
     GLOBAL_EVENTS.with(|global_events| {

leptos_dom/src/events/typed.rs

@@ -1,6 +1,7 @@
 //! Types for all DOM events.
 
-use std::{borrow::Cow, marker::PhantomData};
+use leptos_reactive::Oco;
+use std::marker::PhantomData;
 use wasm_bindgen::convert::FromWasmAbi;
 
 /// A trait for converting types into [web_sys events](web_sys).
@@ -16,10 +17,10 @@ pub trait EventDescriptor: Clone {
     const BUBBLES: bool;
 
     /// The name of the event, such as `click` or `mouseover`.
-    fn name(&self) -> Cow<'static, str>;
+    fn name(&self) -> Oco<'static, str>;
 
     /// The key used for event delegation.
-    fn event_delegation_key(&self) -> Cow<'static, str>;
+    fn event_delegation_key(&self) -> Oco<'static, str>;
 
     /// Return the options for this type. This is only used when you create a [`Custom`] event
     /// handler.
@@ -39,12 +40,12 @@ impl<Ev: EventDescriptor> EventDescriptor for undelegated<Ev> {
     type EventType = Ev::EventType;
 
     #[inline(always)]
-    fn name(&self) -> Cow<'static, str> {
+    fn name(&self) -> Oco<'static, str> {
         self.0.name()
     }
 
     #[inline(always)]
-    fn event_delegation_key(&self) -> Cow<'static, str> {
+    fn event_delegation_key(&self) -> Oco<'static, str> {
         self.0.event_delegation_key()
     }
 
@@ -54,7 +55,7 @@ impl<Ev: EventDescriptor> EventDescriptor for undelegated<Ev> {
 /// A custom event.
 #[derive(Debug)]
 pub struct Custom<E: FromWasmAbi = web_sys::Event> {
-    name: Cow<'static, str>,
+    name: Oco<'static, str>,
     options: Option<web_sys::AddEventListenerOptions>,
     _event_type: PhantomData<E>,
 }
@@ -72,11 +73,11 @@ impl<E: FromWasmAbi> Clone for Custom<E> {
 impl<E: FromWasmAbi> EventDescriptor for Custom<E> {
     type EventType = E;
 
-    fn name(&self) -> Cow<'static, str> {
+    fn name(&self) -> Oco<'static, str> {
         self.name.clone()
     }
 
-    fn event_delegation_key(&self) -> Cow<'static, str> {
+    fn event_delegation_key(&self) -> Oco<'static, str> {
         format!("$$${}", self.name).into()
     }
 
@@ -92,7 +93,7 @@ impl<E: FromWasmAbi> Custom<E> {
     /// Creates a custom event type that can be used within
     /// [`HtmlElement::on`](crate::HtmlElement::on), for events
     /// which are not covered in the [`ev`](crate::ev) module.
-    pub fn new(name: impl Into<Cow<'static, str>>) -> Self {
+    pub fn new(name: impl Into<Oco<'static, str>>) -> Self {
         Self {
             name: name.into(),
             options: None,
@@ -299,12 +300,12 @@ macro_rules! generate_event_types {
           type EventType = web_sys::$web_event;
 
           #[inline(always)]
-          fn name(&self) -> Cow<'static, str> {
+          fn name(&self) -> Oco<'static, str> {
             stringify!([< $($event)+ >]).into()
           }
 
           #[inline(always)]
-          fn event_delegation_key(&self) -> Cow<'static, str> {
+          fn event_delegation_key(&self) -> Oco<'static, str> {
             concat!("$$$", stringify!([< $($event)+ >])).into()
           }