gc_sequence/
map_result.rs

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1use gc_arena::{Collect, MutationContext, StaticCollect};
2
3use crate::Sequence;
4
5#[must_use = "sequences do nothing unless stepped"]
6#[derive(Debug, Collect)]
7#[collect(no_drop)]
8pub struct MapOk<S, F>(S, Option<StaticCollect<F>>);
9
10impl<S, F> MapOk<S, F> {
11    pub fn new(s: S, f: F) -> MapOk<S, F> {
12        MapOk(s, Some(StaticCollect(f)))
13    }
14}
15
16impl<'gc, S, F, I, E, R> Sequence<'gc> for MapOk<S, F>
17where
18    S: Sequence<'gc, Output = Result<I, E>>,
19    F: 'static + FnOnce(I) -> R,
20{
21    type Output = Result<R, E>;
22
23    fn step(&mut self, mc: MutationContext<'gc, '_>) -> Option<Self::Output> {
24        match self.0.step(mc) {
25            Some(Ok(res)) => Some(Ok(self
26                .1
27                .take()
28                .expect("cannot step a finished sequence")
29                .0(res))),
30            Some(Err(err)) => Some(Err(err)),
31            None => None,
32        }
33    }
34}
35
36#[must_use = "sequences do nothing unless stepped"]
37#[derive(Debug, Collect)]
38#[collect(no_drop)]
39pub struct MapOkWith<S, C, F>(S, Option<(C, StaticCollect<F>)>);
40
41impl<S, C, F> MapOkWith<S, C, F> {
42    pub fn new(s: S, c: C, f: F) -> MapOkWith<S, C, F> {
43        MapOkWith(s, Some((c, StaticCollect(f))))
44    }
45}
46
47impl<'gc, S, C, F, I, E, R> Sequence<'gc> for MapOkWith<S, C, F>
48where
49    S: Sequence<'gc, Output = Result<I, E>>,
50    C: Collect,
51    F: 'static + FnOnce(C, I) -> R,
52{
53    type Output = Result<R, E>;
54
55    fn step(&mut self, mc: MutationContext<'gc, '_>) -> Option<Self::Output> {
56        match self.0.step(mc) {
57            Some(Ok(res)) => {
58                let (c, StaticCollect(f)) = self.1.take().expect("cannot step a finished sequence");
59                Some(Ok(f(c, res)))
60            }
61            Some(Err(err)) => Some(Err(err)),
62            None => None,
63        }
64    }
65}
66
67#[must_use = "sequences do nothing unless stepped"]
68#[derive(Debug, Collect)]
69#[collect(no_drop)]
70pub struct MapError<S, F>(S, Option<StaticCollect<F>>);
71
72impl<S, F> MapError<S, F> {
73    pub fn new(s: S, f: F) -> MapError<S, F> {
74        MapError(s, Some(StaticCollect(f)))
75    }
76}
77
78impl<'gc, S, F, I, E, R> Sequence<'gc> for MapError<S, F>
79where
80    S: Sequence<'gc, Output = Result<I, E>>,
81    F: 'static + FnOnce(E) -> R,
82{
83    type Output = Result<I, R>;
84
85    fn step(&mut self, mc: MutationContext<'gc, '_>) -> Option<Self::Output> {
86        match self.0.step(mc) {
87            Some(Ok(res)) => Some(Ok(res)),
88            Some(Err(err)) => Some(Err(self
89                .1
90                .take()
91                .expect("cannot step a finished sequence")
92                .0(err))),
93            None => None,
94        }
95    }
96}
gc_sequence/map_result.rs

gc_sequence/
map_result.rs
