From c162e63b1d2ba5975dd7f31beeb0bb785ff5f457 Mon Sep 17 00:00:00 2001
From: Michael Sippel <micha@fragmental.art>
Date: Mon, 10 May 2021 01:50:01 +0200
Subject: [PATCH] sequence map
---
nested/src/sequence/map.rs | 90 ++++++++++++++++++++++++++++++++++++++
nested/src/sequence/mod.rs | 1 +
2 files changed, 91 insertions(+)
create mode 100644 nested/src/sequence/map.rs
diff --git a/nested/src/sequence/map.rs b/nested/src/sequence/map.rs
new file mode 100644
index 0000000..dc2d1c1
--- /dev/null
+++ b/nested/src/sequence/map.rs
@@ -0,0 +1,90 @@
+use {
+ std::sync::Arc,
+ std::sync::RwLock,
+ crate::{
+ sequence::{SequenceView},
+ core::{
+ Observer, ObserverExt, ObserverBroadcast,
+ View, ViewPort, InnerViewPort, OuterViewPort
+ }
+ }
+};
+
+//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
+
+impl<Item: 'static> OuterViewPort<dyn SequenceView<Item = Item>> {
+ pub fn map<
+ DstItem: 'static,
+ F: Fn(&Item) -> DstItem + Send + Sync + 'static
+ >(
+ &self,
+ f: F
+ ) -> OuterViewPort<dyn SequenceView<Item = DstItem>> {
+ let port = ViewPort::new();
+ let map = Arc::new(RwLock::new(MapSequenceItem {
+ src_view: None,
+ f,
+ cast: port.inner().get_broadcast()
+ }));
+
+ self.add_observer(map.clone());
+ port.inner().set_view(Some(map));
+ port.into_outer()
+ }
+}
+
+//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
+
+pub struct MapSequenceItem<DstItem, SrcView, F>
+where SrcView: SequenceView + ?Sized,
+ F: Fn(&SrcView::Item) -> DstItem + Send + Sync
+{
+ src_view: Option<Arc<SrcView>>,
+ f: F,
+ cast: Arc<RwLock<ObserverBroadcast<dyn SequenceView<Item = DstItem>>>>
+}
+
+//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
+
+impl<DstItem, SrcView, F> View for MapSequenceItem<DstItem, SrcView, F>
+where SrcView: SequenceView + ?Sized,
+ F: Fn(&SrcView::Item) -> DstItem + Send + Sync
+{
+ type Msg = usize;
+}
+
+impl<DstItem, SrcView, F> SequenceView for MapSequenceItem<DstItem, SrcView, F>
+where SrcView: SequenceView + ?Sized,
+ F: Fn(&SrcView::Item) -> DstItem + Send + Sync
+{
+ type Item = DstItem;
+
+ fn len(&self) -> Option<usize> {
+ self.src_view.len()
+ }
+
+ fn get(&self, idx: &usize) -> Option<DstItem> {
+ self.src_view.get(idx).as_ref().map(|item| (self.f)(item))
+ }
+}
+
+//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
+
+impl<DstItem, SrcView, F> Observer<SrcView> for MapSequenceItem<DstItem, SrcView, F>
+where SrcView: SequenceView + ?Sized,
+ F: Fn(&SrcView::Item) -> DstItem + Send + Sync
+{
+ fn reset(&mut self, view: Option<Arc<SrcView>>) {
+ let old_len = self.len();
+ self.src_view = view;
+ let new_len = self.len();
+
+ if let Some(len) = old_len { self.cast.notify_each(0 .. len ); }
+ if let Some(len) = new_len { self.cast.notify_each(0 .. len ); }
+ }
+
+ fn notify(&self, msg: &usize) {
+ self.cast.notify(msg);
+ }
+}
+
diff --git a/nested/src/sequence/mod.rs b/nested/src/sequence/mod.rs
index 2dda5fa..d0f8366 100644
--- a/nested/src/sequence/mod.rs
+++ b/nested/src/sequence/mod.rs
@@ -1,6 +1,7 @@
pub mod seq2idx;
pub mod vec_buffer;
+pub mod map;
pub mod flatten;
pub use {