par_stream/builder/
fn_factory.rs

1pub type BoxFnFactory<In, Out> = Box<dyn FnMut(In) -> BoxFn<'static, Out> + Send>;
2pub(crate) type BoxFn<'a, T> = Box<dyn FnOnce() -> T + Send + 'a>;
3
4pub trait FnFactory<In, Out>
5where
6    Self::Fn: 'static + Send + FnOnce() -> Out,
7    In: 'static + Send,
8    Out: 'static + Send,
9{
10    type Fn;
11
12    fn generate(&mut self, input: In) -> Self::Fn;
13
14    fn boxed(self) -> BoxFnFactory<In, Out>
15    where
16        Self: 'static + Send;
17
18    fn chain<GOut, G>(self, other: G) -> BoxFnFactory<In, GOut>
19    where
20        Self: 'static + Send + Sized,
21        G: 'static + Send + Clone + FnFactory<Out, GOut>,
22        GOut: 'static + Send,
23        G::Fn: 'static + Send + FnOnce() -> GOut;
24}
25
26impl<F, In, Out, Func> FnFactory<In, Out> for F
27where
28    F: FnMut(In) -> Func,
29    Func: 'static + Send + FnOnce() -> Out,
30    In: 'static + Send,
31    Out: 'static + Send,
32{
33    type Fn = Func;
34
35    fn generate(&mut self, input: In) -> Self::Fn {
36        self(input)
37    }
38
39    fn boxed(mut self) -> BoxFnFactory<In, Out>
40    where
41        Self: 'static + Send,
42    {
43        Box::new(move |input: In| -> BoxFn<'static, Out> { Box::new(self.generate(input)) })
44    }
45
46    fn chain<GOut, G>(mut self, other: G) -> BoxFnFactory<In, GOut>
47    where
48        Self: 'static + Send + Sized,
49        G: 'static + Send + Clone + FnFactory<Out, GOut>,
50        GOut: 'static + Send,
51    {
52        Box::new(move |input: In| -> BoxFn<'static, GOut> {
53            let func1 = self.generate(input);
54            let mut g = other.clone();
55
56            Box::new(move || {
57                let mid = func1();
58                let func2 = g.generate(mid);
59                func2()
60            })
61        })
62    }
63}
par_stream/builder/fn_factory.rs

par_stream/builder/
fn_factory.rs
