add ReverseSequence projection

This commit is contained in:
Michael Sippel 2024-05-23 02:05:11 +02:00
parent e50a788e82
commit b977ab6d26
Signed by: senvas
GPG key ID: F96CF119C34B64A6
2 changed files with 143 additions and 0 deletions

View file

@ -22,4 +22,5 @@ pub mod map_index_item;
pub mod map_index_key; pub mod map_index_key;
pub mod grid_offset; pub mod grid_offset;
pub mod decorate_sequence; pub mod decorate_sequence;
pub mod reverse_sequence;

View file

@ -0,0 +1,142 @@
use {
crate::{
view::{
Observer, ObserverBroadcast, ObserverExt, OuterViewPort, View, ViewPort,
sequence::SequenceView,
},
},
std::sync::Arc,
std::sync::RwLock,
};
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
impl<Item: 'static> OuterViewPort<dyn SequenceView<Item = Item>> {
pub fn reverse(&self) -> OuterViewPort<dyn SequenceView<Item = Item>> {
let port = ViewPort::new();
port.add_update_hook(Arc::new(self.0.clone()));
let map = Arc::new(RwLock::new(ReverseSequence {
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 ReverseSequence<SrcView>
where SrcView: SequenceView + ?Sized
{
src_view: Option<Arc<SrcView>>,
end: usize,
cast: Arc<RwLock<ObserverBroadcast<dyn SequenceView<Item = SrcView::Item>>>>
}
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
impl<SrcView> View for ReverseSequence<SrcView>
where SrcView: SequenceView + ?Sized
{
type Msg = usize;
}
impl<SrcView> SequenceView for ReverseSequence<SrcView>
where SrcView: SequenceView + ?Sized
{
type Item = SrcView::Item;
fn len(&self) -> Option<usize> {
self.src_view.len()
}
fn get(&self, idx: &usize) -> Option<Self::Item> {
let len = self.src_view.len().unwrap();
if *idx < len {
let end = len - 1;
self.src_view.get( &(end - idx) )
} else {
None
}
}
}
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
impl<SrcView> Observer<SrcView> for ReverseSequence<SrcView>
where SrcView: SequenceView + ?Sized
{
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);
self.end = if len > 0 { len - 1 } else { 0 };
}
}
fn notify(&mut self, idx: &usize) {
/* todo optimize
*/
let len = self.src_view.len().unwrap();
let new_end = if len > 0 { len - 1 } else { 0 };
if new_end < self.end {
self.cast.notify_each( 0 ..= self.end );
self.end = new_end;
} else {
self.cast.notify_each( 0 ..= new_end );
self.end = new_end;
// self.cast.notify( &(self.end - idx) );
}
}
}
//<<<<>>>><<>><><<>><<<*>>><<>><><<>><<<<>>>>
#[cfg(test)]
mod tests {
use crate::buffer::vec::*;
use crate::projection::map_sequence::*;
use crate::view::{port::UpdateTask, sequence::SequenceView};
#[test]
fn rev_seq1() {
let mut buffer = VecBuffer::new();
let target_port = buffer.get_port().to_sequence().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);
}
}