1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
use std::ops::BitOr;
use signalo_traits::{Filter, Finalize, Sink, Source};
use pipe::Pipe;
#[derive(Default, Clone, Debug)]
pub struct UnitPipe<T> {
inner: T,
}
impl<T> UnitPipe<T> {
#[inline]
pub fn new(inner: T) -> Self {
Self { inner }
}
}
impl<T, Rhs> BitOr<Rhs> for UnitPipe<T> {
type Output = Pipe<Self, Rhs>;
#[inline]
fn bitor(self, rhs: Rhs) -> Self::Output {
Pipe::new(self, rhs)
}
}
impl<T, I> Filter<I> for UnitPipe<T>
where
T: Filter<I>,
{
type Output = T::Output;
#[inline]
fn filter(&mut self, input: I) -> Self::Output {
self.inner.filter(input)
}
}
impl<T> Source for UnitPipe<T>
where
T: Source,
{
type Output = T::Output;
#[inline]
fn source(&mut self) -> Option<Self::Output> {
self.inner.source()
}
}
impl<T, I> Sink<I> for UnitPipe<T>
where
T: Sink<I>,
{
#[inline]
fn sink(&mut self, input: I) {
self.inner.sink(input)
}
}
impl<T> Finalize for UnitPipe<T>
where
T: Finalize,
{
type Output = T::Output;
#[inline]
fn finalize(self) -> Self::Output {
self.inner.finalize()
}
}
#[cfg(test)]
mod tests {
use super::*;
type Value = usize;
struct DummyFilterAdd;
impl Filter<Value> for DummyFilterAdd {
type Output = Value;
#[inline]
fn filter(&mut self, input: Value) -> Self::Output {
input + 1
}
}
#[test]
fn test() {
let input = vec![
0, 1, 7, 2, 5, 8, 16, 3, 19, 6, 14, 9, 9, 17, 17, 4, 12, 20, 20, 7,
];
let filter = DummyFilterAdd;
let pipe = UnitPipe::new(filter);
let subject: Vec<_> = input
.iter()
.scan(pipe, |pipe, &input| Some(pipe.filter(input)))
.collect();
let expected = vec![
1, 2, 8, 3, 6, 9, 17, 4, 20, 7, 15, 10, 10, 18, 18, 5, 13, 21, 21, 8,
];
assert_eq!(subject, expected);
}
}