treaty -


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

use core::ops::ControlFlow;

use crate::{
    effect::{Effect, Future},
    higher_ranked_type,
    hkt::AnySend,
    nameable,
    protocol::{walker::hint::HintMeta, Visitor}, Flow, never::Never,
};

pub trait Sequence<'ctx> {
    type Effect: Effect<'ctx>;

    fn visit<'a>(
        &'a mut self,
        scope: DynSequenceScope<'a, 'ctx, Self::Effect>,
    ) -> Future<'a, 'ctx, Flow<Never>, Self::Effect>;
}

pub type DynSequence<'a, 'ctx, E> = dyn Sequence<'ctx, Effect = E> + Send + 'a;

nameable! {
    pub struct Name['a, 'ctx, E];

    impl [E] for DynSequence<'a, 'ctx, E> where {
        E: Effect<'ctx>,
        'ctx: 'a
    }

    impl [E] where DynSequence<'a, 'ctx, E> {
        E: Effect<'ctx>,
        'ctx: 'a
    }
}

pub trait SequenceScope<'ctx> {
    type Effect: Effect<'ctx>;

    fn size_hint<'a>(
        &'a mut self,
    ) -> Future<'a, 'ctx, (usize, Option<usize>), Self::Effect>;

    fn next<'a>(
        &'a mut self,
        visitor: Visitor<'a, 'ctx>,
    ) -> Future<'a, 'ctx, SequenceFlow, Self::Effect>;
}

pub type DynSequenceScope<'a, 'ctx, E> = &'a mut (dyn SequenceScope<'ctx, Effect = E> + Send + 'a);

#[derive(PartialEq, Eq, PartialOrd, Ord, Copy, Clone, Debug)]
pub enum SequenceFlow {
    Done,
    Continue,
    Break,
}

higher_ranked_type! {
    pub type KnownHkt['ctx]: (AnySend) = for<'lt> Known
}

#[derive(Default)]
pub struct Known {
    pub len: (usize, Option<usize>),
}

pub struct Hint {
    pub len: (usize, Option<usize>),
}

impl<'a, 'ctx: 'a, E: Effect<'ctx>> HintMeta<'ctx> for DynSequence<'a, 'ctx, E> {
    type Known = KnownHkt<'ctx>;

    type Hint = Hint;
}