another_rxrust/operators/
sum.rs

1use crate::internals::stream_controller::*;
2use crate::prelude::*;
3use std::{
4  marker::PhantomData,
5  ops::Add,
6  sync::{Arc, RwLock},
7};
8
9#[derive(Clone)]
10pub struct Sum<Item> {
11  _item: PhantomData<Item>,
12}
13
14impl<'a, Item> Sum<Item>
15where
16  Item: Clone + Send + Sync + Add<Output = Item>,
17{
18  pub fn new() -> Sum<Item> {
19    Sum { _item: PhantomData }
20  }
21  pub fn execute(&self, source: Observable<'a, Item>) -> Observable<'a, Item> {
22    Observable::<Item>::create(move |s| {
23      let sum = Arc::new(RwLock::new(None::<Item>));
24
25      let sctl = StreamController::new(s);
26      let sctl_error = sctl.clone();
27      let sctl_complete = sctl.clone();
28
29      let sum_next = Arc::clone(&sum);
30
31      source.inner_subscribe(sctl.new_observer(
32        move |_, x| {
33          let mut sum = sum_next.write().unwrap();
34          if let Some(latest) = &*sum {
35            *sum = Some(latest.clone() + x);
36          } else {
37            *sum = Some(x);
38          }
39        },
40        move |_, e| {
41          sctl_error.sink_error(e);
42        },
43        move |serial| {
44          if let Some(latest) = &*sum.read().unwrap() {
45            sctl_complete.sink_next(latest.clone());
46          }
47          sctl_complete.sink_complete(&serial);
48        },
49      ));
50    })
51  }
52}
53
54impl<'a, Item> Observable<'a, Item>
55where
56  Item: Clone + Send + Sync + Add<Output = Item>,
57{
58  pub fn sum(&self) -> Observable<'a, Item> {
59    Sum::new().execute(self.clone())
60  }
61}
62
63#[cfg(test)]
64mod test {
65  use crate::prelude::*;
66
67  #[test]
68  fn basic() {
69    observables::from_iter(1..10).sum().subscribe(
70      print_next_fmt!("{}"),
71      print_error!(),
72      print_complete!(),
73    );
74  }
75
76  #[test]
77  fn empty() {
78    observables::empty::<i32>().sum().subscribe(
79      print_next_fmt!("{}"),
80      print_error!(),
81      print_complete!(),
82    );
83  }
84
85  #[test]
86  fn error() {
87    Observable::create(|s| {
88      s.next(1);
89      s.error(RxError::from_error("ERR!"))
90    })
91    .sum()
92    .subscribe(
93      print_next_fmt!("{}"),
94      print_error_as!(&str),
95      print_complete!(),
96    );
97  }
98}
another_rxrust/operators/sum.rs

another_rxrust/operators/
sum.rs
