Add ObservableVectorTransaction

eyeball-im-util/src/lib.rs

@@ -1,7 +1,3 @@
 //! Helpful utilities for [`eyeball-im`][eyeball_im].
-//!
-//! The primary entry point of this library is [`VectorExt`].
 
 pub mod vector;
-
-pub use vector::VectorExt;

eyeball-im-util/src/vector.rs

@@ -1,51 +1,97 @@
-//! Utilities around [`ObservableVector`].
-
-use eyeball_im::{ObservableVector, Vector, VectorSubscriber};
+//! Utilities around [`ObservableVector`][eyeball_im::ObservableVector].
 
 mod filter;
 
+use eyeball_im::VectorDiff;
+use futures_core::Stream;
+
 pub use self::filter::{Filter, FilterMap};
 
-/// Extension trait for [`ObservableVector`].
-pub trait VectorExt<T>
-where
-    T: Clone + Send + Sync + 'static,
-{
-    /// Obtain a new subscriber that filters items by the given filter function.
-    ///
-    /// Returns a filtered version of the current vector, and a subscriber to
-    /// get updates through.
-    fn subscribe_filter<F>(&self, f: F) -> (Vector<T>, Filter<VectorSubscriber<T>, F>)
-    where
-        F: Fn(&T) -> bool;
-
-    /// Obtain a new subscriber that filters and maps items with the given
-    /// function.
-    ///
-    /// Returns a filtered + mapped version of the current vector, and a
-    /// subscriber to get updates through.
-    fn subscribe_filter_map<U, F>(&self, f: F) -> (Vector<U>, FilterMap<VectorSubscriber<T>, F>)
-    where
-        U: Clone,
-        F: Fn(T) -> Option<U>;
-}
-
-impl<T> VectorExt<T> for ObservableVector<T>
-where
-    T: Clone + Send + Sync + 'static,
-{
-    fn subscribe_filter<F>(&self, f: F) -> (Vector<T>, Filter<VectorSubscriber<T>, F>)
-    where
-        F: Fn(&T) -> bool,
-    {
-        Filter::new((*self).clone(), self.subscribe(), f)
+/// Abstraction over stream items that the adapters in this module can deal
+/// with.
+pub trait VectorDiffContainer: VectorDiffContainerOps<Self::Element> {
+    /// The element type of the [`Vector`][imbl::Vector] that diffs are being
+    /// handled for.
+    type Element;
+}
+
+impl<T> VectorDiffContainer for VectorDiff<T> {
+    type Element = T;
+}
+
+impl<T> VectorDiffContainer for Vec<VectorDiff<T>> {
+    type Element = T;
+}
+
+/// Type alias for extracting the element type from a stream of
+/// [`VectorDiffContainer`]s.
+pub type VectorDiffContainerStreamElement<S> =
+    <<S as Stream>::Item as VectorDiffContainer>::Element;
+
+/// Type alias for extracting the [`VectorDiffContainerFamily`] type from a
+/// stream of [`VectorDiffContainer`]s.
+type VectorDiffContainerStreamFamily<S> =
+    <<S as Stream>::Item as VectorDiffContainerOps<VectorDiffContainerStreamElement<S>>>::Family;
+
+/// Type alias for extracting the stream item type after the element type was
+/// mapped to the given type `U`, from a stream of [`VectorDiffContainer`]s.
+pub type VectorDiffContainerStreamMappedItem<S, U> =
+    <VectorDiffContainerStreamFamily<S> as VectorDiffContainerFamily>::Member<U>;
+
+#[doc(hidden)]
+pub trait VectorDiffContainerOps<T> {
+    type Family: VectorDiffContainerFamily;
+
+    fn filter_map<U>(
+        self,
+        f: impl FnMut(VectorDiff<T>) -> Option<VectorDiff<U>>,
+    ) -> Option<<Self::Family as VectorDiffContainerFamily>::Member<U>>;
+}
+
+impl<T> VectorDiffContainerOps<T> for VectorDiff<T> {
+    type Family = VectorDiffFamily;
+
+    fn filter_map<U>(
+        self,
+        mut f: impl FnMut(VectorDiff<T>) -> Option<VectorDiff<U>>,
+    ) -> Option<<Self::Family as VectorDiffContainerFamily>::Member<U>> {
+        f(self)
     }
+}
 
-    fn subscribe_filter_map<U, F>(&self, f: F) -> (Vector<U>, FilterMap<VectorSubscriber<T>, F>)
-    where
-        U: Clone,
-        F: Fn(T) -> Option<U>,
-    {
-        FilterMap::new((*self).clone(), self.subscribe(), f)
+impl<T> VectorDiffContainerOps<T> for Vec<VectorDiff<T>> {
+    type Family = VecVectorDiffFamily;
+
+    fn filter_map<U>(
+        self,
+        f: impl FnMut(VectorDiff<T>) -> Option<VectorDiff<U>>,
+    ) -> Option<<Self::Family as VectorDiffContainerFamily>::Member<U>> {
+        let res: Vec<_> = self.into_iter().filter_map(f).collect();
+        if res.is_empty() {
+            None
+        } else {
+            Some(res)
+        }
     }
 }
+
+#[doc(hidden)]
+pub trait VectorDiffContainerFamily {
+    type Member<T>: VectorDiffContainerOps<T, Family = Self>;
+}
+
+#[doc(hidden)]
+#[derive(Debug)]
+pub enum VectorDiffFamily {}
+
+impl VectorDiffContainerFamily for VectorDiffFamily {
+    type Member<T> = VectorDiff<T>;
+}
+
+#[doc(hidden)]
+#[derive(Debug)]
+pub enum VecVectorDiffFamily {}
+
+impl VectorDiffContainerFamily for VecVectorDiffFamily {
+    type Member<T> = Vec<VectorDiff<T>>;
+}