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Commit | Line | Data |
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b7449926 | 1 | // run-pass |
0bf4aa26 | 2 | #![allow(unused_must_use)] |
abe05a73 XL |
3 | fn main() { |
4 | if false { test(); } | |
5 | } | |
6 | ||
7 | fn test() { | |
8 | let rx = Err::<Vec<usize>, u32>(1).into_future(); | |
9 | ||
10 | rx.map(|l: Vec<usize>| stream::iter(l.into_iter().map(|i| Ok(i)))) | |
11 | .flatten_stream() | |
12 | .chunks(50) | |
13 | .buffer_unordered(5); | |
14 | } | |
15 | ||
16 | use future::{Future, IntoFuture}; | |
17 | mod future { | |
18 | use std::result; | |
19 | ||
20 | use {stream, Stream}; | |
21 | ||
22 | pub trait Future { | |
23 | type Item; | |
24 | type Error; | |
25 | ||
26 | fn map<F, U>(self, _: F) -> Map<Self, F> | |
27 | where F: FnOnce(Self::Item) -> U, | |
28 | Self: Sized, | |
29 | { | |
30 | panic!() | |
31 | } | |
32 | ||
33 | fn flatten_stream(self) -> FlattenStream<Self> | |
34 | where <Self as Future>::Item: stream::Stream<Error=Self::Error>, | |
35 | Self: Sized | |
36 | { | |
37 | panic!() | |
38 | } | |
39 | } | |
40 | ||
41 | pub trait IntoFuture { | |
42 | type Future: Future<Item=Self::Item, Error=Self::Error>; | |
43 | type Item; | |
44 | type Error; | |
45 | fn into_future(self) -> Self::Future; | |
46 | } | |
47 | ||
48 | impl<F: Future> IntoFuture for F { | |
49 | type Future = F; | |
50 | type Item = F::Item; | |
51 | type Error = F::Error; | |
52 | ||
53 | fn into_future(self) -> F { | |
54 | panic!() | |
55 | } | |
56 | } | |
57 | ||
58 | impl<T, E> IntoFuture for result::Result<T, E> { | |
59 | type Future = FutureResult<T, E>; | |
60 | type Item = T; | |
61 | type Error = E; | |
62 | ||
63 | fn into_future(self) -> FutureResult<T, E> { | |
64 | panic!() | |
65 | } | |
66 | } | |
67 | ||
68 | pub struct Map<A, F> { | |
69 | _a: (A, F), | |
70 | } | |
71 | ||
72 | impl<U, A, F> Future for Map<A, F> | |
73 | where A: Future, | |
74 | F: FnOnce(A::Item) -> U, | |
75 | { | |
76 | type Item = U; | |
77 | type Error = A::Error; | |
78 | } | |
79 | ||
80 | pub struct FlattenStream<F> { | |
81 | _f: F, | |
82 | } | |
83 | ||
84 | impl<F> Stream for FlattenStream<F> | |
85 | where F: Future, | |
86 | <F as Future>::Item: Stream<Error=F::Error>, | |
87 | { | |
88 | type Item = <F::Item as Stream>::Item; | |
89 | type Error = <F::Item as Stream>::Error; | |
90 | } | |
91 | ||
92 | pub struct FutureResult<T, E> { | |
93 | _inner: (T, E), | |
94 | } | |
95 | ||
96 | impl<T, E> Future for FutureResult<T, E> { | |
97 | type Item = T; | |
98 | type Error = E; | |
99 | } | |
100 | } | |
101 | ||
102 | mod stream { | |
103 | use IntoFuture; | |
104 | ||
105 | pub trait Stream { | |
106 | type Item; | |
107 | type Error; | |
108 | ||
109 | fn buffer_unordered(self, amt: usize) -> BufferUnordered<Self> | |
110 | where Self::Item: IntoFuture<Error = <Self as Stream>::Error>, | |
111 | Self: Sized | |
112 | { | |
113 | new(self, amt) | |
114 | } | |
115 | ||
116 | fn chunks(self, _capacity: usize) -> Chunks<Self> | |
117 | where Self: Sized | |
118 | { | |
119 | panic!() | |
120 | } | |
121 | } | |
122 | ||
123 | pub struct IterStream<I> { | |
124 | _iter: I, | |
125 | } | |
126 | ||
127 | pub fn iter<J, T, E>(_: J) -> IterStream<J::IntoIter> | |
128 | where J: IntoIterator<Item=Result<T, E>>, | |
129 | { | |
130 | panic!() | |
131 | } | |
132 | ||
133 | impl<I, T, E> Stream for IterStream<I> | |
134 | where I: Iterator<Item=Result<T, E>>, | |
135 | { | |
136 | type Item = T; | |
137 | type Error = E; | |
138 | } | |
139 | ||
140 | pub struct Chunks<S> { | |
141 | _stream: S | |
142 | } | |
143 | ||
144 | impl<S> Stream for Chunks<S> | |
145 | where S: Stream | |
146 | { | |
147 | type Item = Result<Vec<<S as Stream>::Item>, u32>; | |
148 | type Error = <S as Stream>::Error; | |
149 | } | |
150 | ||
151 | pub struct BufferUnordered<S> { | |
152 | _stream: S, | |
153 | } | |
154 | ||
155 | enum Slot<T> { | |
064997fb | 156 | Next(#[allow(unused_tuple_struct_fields)] usize), |
abe05a73 XL |
157 | _Data { _a: T }, |
158 | } | |
159 | ||
160 | fn new<S>(_s: S, _amt: usize) -> BufferUnordered<S> | |
161 | where S: Stream, | |
162 | S::Item: IntoFuture<Error=<S as Stream>::Error>, | |
163 | { | |
164 | (0..0).map(|_| { | |
165 | Slot::Next::<<S::Item as IntoFuture>::Future>(1) | |
166 | }).collect::<Vec<_>>(); | |
167 | panic!() | |
168 | } | |
169 | ||
170 | impl<S> Stream for BufferUnordered<S> | |
171 | where S: Stream, | |
172 | S::Item: IntoFuture<Error=<S as Stream>::Error>, | |
173 | { | |
174 | type Item = <S::Item as IntoFuture>::Item; | |
175 | type Error = <S as Stream>::Error; | |
176 | } | |
177 | } | |
178 | use stream::Stream; |