From e2c8ea8441b0cf1bbeddb73f1c9fff577ec4d2ea Mon Sep 17 00:00:00 2001
From: Michael Sippel <micha@fragmental.art>
Date: Sun, 2 Jun 2024 17:24:32 +0200
Subject: [PATCH] list reverse projection
---
src/projection/filter_sequence.rs | 5 +-
src/projection/mod.rs | 1 +
src/projection/reverse_list.rs | 153 ++++++++++++++++++++++++++++++
3 files changed, 158 insertions(+), 1 deletion(-)
create mode 100644 src/projection/reverse_list.rs
diff --git a/src/projection/filter_sequence.rs b/src/projection/filter_sequence.rs
index a6e2b45..6819e3d 100644
--- a/src/projection/filter_sequence.rs
+++ b/src/projection/filter_sequence.rs
@@ -135,7 +135,10 @@ where
opds.resize_with(1 + *idx, || false);
let op = opds.get(*idx).cloned().unwrap_or(false);
- *opds.get_mut(*idx).unwrap() = np;
+ // if let Some(o) = opds.get_mut(*idx) {
+ // *o = np;
+ // }
+ *opds.get_mut(*idx).unwrap() = np;
drop(opds);
diff --git a/src/projection/mod.rs b/src/projection/mod.rs
index b3ae110..d6d3875 100644
--- a/src/projection/mod.rs
+++ b/src/projection/mod.rs
@@ -23,4 +23,5 @@ pub mod map_index_key;
pub mod grid_offset;
pub mod decorate_sequence;
pub mod reverse_sequence;
+pub mod reverse_list;
diff --git a/src/projection/reverse_list.rs b/src/projection/reverse_list.rs
new file mode 100644
index 0000000..c020233
--- /dev/null
+++ b/src/projection/reverse_list.rs
@@ -0,0 +1,153 @@
+use {
+ crate::{
+ view::{
+ Observer, ObserverBroadcast, ObserverExt, OuterViewPort, View, ViewPort,
+ list::{ListDiff, ListView, ListViewExt},
+ },
+ },
+ std::sync::Arc,
+ std::sync::RwLock,
+};
+
+//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
+
+impl<Item: Clone + Send + Sync + 'static> OuterViewPort<dyn ListView<Item>> {
+ pub fn reverse(&self) -> OuterViewPort<dyn ListView<Item>> {
+ let port = ViewPort::new();
+ port.add_update_hook(Arc::new(self.0.clone()));
+
+ let map = Arc::new(RwLock::new(ReverseList {
+ src_view: None,
+ end: 0,
+ cast: port.inner().get_broadcast(),
+ }));
+
+ self.add_observer(map.clone());
+ port.inner().set_view(Some(map));
+ port.into_outer()
+ }
+}
+
+//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
+
+pub struct ReverseList<SrcView, Item>
+where Item: Clone + Send + Sync + 'static,
+ SrcView: ListView<Item> + ?Sized
+{
+ src_view: Option<Arc<SrcView>>,
+ end: usize,
+ cast: Arc<RwLock<ObserverBroadcast<dyn ListView<Item>>>>
+}
+
+//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
+
+impl<SrcView, Item> View for ReverseList<SrcView, Item>
+where Item: Clone + Send + Sync + 'static,
+ SrcView: ListView<Item> + ?Sized
+{
+ type Msg = ListDiff<Item>;
+}
+
+impl<SrcView, Item> ListView<Item> for ReverseList<SrcView, Item>
+where Item: Clone + Send + Sync + 'static,
+ SrcView: ListView<Item> + ?Sized
+{
+ fn len(&self) -> Option<usize> {
+ Some(self.end)
+ }
+
+ fn get(&self, idx: &usize) -> Option<Item> {
+ if *idx < self.end {
+ self.src_view.get( &(self.end - idx - 1) )
+ } else {
+ None
+ }
+ }
+}
+
+//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
+
+impl<Item, SrcView> Observer<SrcView> for ReverseList<SrcView, Item>
+where Item: Clone + Send + Sync + 'static,
+ SrcView: ListView<Item> + ?Sized
+{
+ fn reset(&mut self, view: Option<Arc<SrcView>>) {
+ self.src_view = view;
+
+ self.cast.notify(&ListDiff::Clear);
+ if let Some(v) = self.src_view.as_ref() {
+ self.end = v.len().unwrap();
+ for idx in 0 .. self.end {
+ if idx < self.end {
+ let val = v.get( &(self.end - idx - 1) ).unwrap();
+ self.cast.notify(&ListDiff::Insert{ idx: idx, val });
+ }
+ }
+ }
+ }
+
+ fn notify(&mut self, msg: &ListDiff<Item>) {
+ /* todo optimize
+ */
+ //let len = self.src_view.len().unwrap();
+
+ self.cast.notify(&match msg {
+ ListDiff::Clear => {
+ self.end = 0;
+ ListDiff::Clear
+ },
+ ListDiff::Remove(mut idx) => {
+ self.end -= 1;
+ idx = self.end - idx;
+ ListDiff::Remove(idx)
+ }
+ ListDiff::Insert{ mut idx, val } => {
+ idx = self.end - idx;
+ self.end += 1;
+ ListDiff::Insert{ idx, val:val.clone() }
+ }
+ ListDiff::Update{ mut idx, val } => {
+ idx = self.end - idx - 1;
+ ListDiff::Update{ idx, val:val.clone() }
+ }
+ });
+ }
+}
+
+//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
+
+#[cfg(test)]
+mod tests {
+ use crate::buffer::vec::*;
+ use crate::view::{port::UpdateTask, list::ListView};
+
+ #[test]
+ fn rev_list1() {
+ let mut buffer = VecBuffer::new();
+
+ let target_port = buffer.get_port().to_list().reverse();
+ let target_view = target_port.get_view();
+
+ buffer.push(0);
+ buffer.push(7);
+ buffer.push(9);
+
+ target_port.0.update();
+
+ assert_eq!(target_view.len(), Some(3));
+
+ assert_eq!(target_view.get(&0), Some(9));
+ assert_eq!(target_view.get(&1), Some(7));
+ assert_eq!(target_view.get(&2), Some(0));
+ assert_eq!(target_view.get(&3), None);
+
+ buffer.remove(0);
+
+ target_port.0.update();
+ assert_eq!(target_view.len(), Some(2));
+ assert_eq!(target_view.get(&0), Some(9));
+ assert_eq!(target_view.get(&1), Some(7));
+ assert_eq!(target_view.get(&2), None);
+ }
+}
+