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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136

use chargrid_core::{Component, Ctx, Event, FrameBuffer, Size};
use std::marker::PhantomData;

mod boxed;
mod unboxed;

pub use boxed::*;

pub trait Lens {
    type Input;
    type Output;
    fn get<'a>(&self, input: &'a Self::Input) -> &'a Self::Output;
    fn get_mut<'a>(&mut self, input: &'a mut Self::Input) -> &'a mut Self::Output;
}

pub struct LensFns<I, O, R, M> {
    input: PhantomData<I>,
    output: PhantomData<O>,
    get: R,
    get_mut: M,
}

impl<I, O, R, M> LensFns<I, O, R, M> {
    pub fn new(get: R, get_mut: M) -> Self {
        Self {
            input: PhantomData,
            output: PhantomData,
            get,
            get_mut,
        }
    }
}

impl<I, O, R, M> Lens for LensFns<I, O, R, M>
where
    R: Fn(&I) -> &O,
    M: FnMut(&mut I) -> &mut O,
{
    type Input = I;
    type Output = O;
    fn get<'a>(&self, input: &'a Self::Input) -> &'a Self::Output {
        (self.get)(input)
    }
    fn get_mut<'a>(&mut self, input: &'a mut Self::Input) -> &'a mut Self::Output {
        (self.get_mut)(input)
    }
}

pub struct LensState<S, L, C>
where
    C: Component,
    L: Lens<Input = S, Output = C::State>,
{
    state: PhantomData<S>,
    lens: L,
    component: C,
}

impl<S, L, C> Component for LensState<S, L, C>
where
    C: Component,
    L: Lens<Input = S, Output = C::State>,
{
    type Output = C::Output;
    type State = S;

    fn render(&self, state: &Self::State, ctx: Ctx, fb: &mut FrameBuffer) {
        self.component.render(&self.lens.get(state), ctx, fb);
    }
    fn update(&mut self, state: &mut Self::State, ctx: Ctx, event: Event) -> Self::Output {
        self.component.update(self.lens.get_mut(state), ctx, event)
    }
    fn size(&self, state: &Self::State, ctx: Ctx) -> Size {
        self.component.size(self.lens.get(state), ctx)
    }
}

#[derive(Clone, Copy, Debug)]
pub enum LoopControl<Co, Br> {
    Continue(Co),
    Break(Br),
}

impl<Co, Br> LoopControl<Co, Br> {
    pub fn map_continue<Co2, F: FnOnce(Co) -> Co2>(self, f: F) -> LoopControl<Co2, Br> {
        match self {
            Self::Continue(co) => LoopControl::Continue(f(co)),
            Self::Break(br) => LoopControl::Break(br),
        }
    }
    pub fn map_break<Br2, F: FnOnce(Br) -> Br2>(self, f: F) -> LoopControl<Co, Br2> {
        match self {
            Self::Continue(co) => LoopControl::Continue(co),
            Self::Break(br) => LoopControl::Break(f(br)),
        }
    }
}

#[derive(Clone, Copy, Debug)]
pub struct Close;
pub type OrClose<T> = Result<T, Close>;

#[derive(Clone, Copy, Debug)]
pub struct Escape;
pub type OrEscape<T> = Result<T, Escape>;

#[derive(Clone, Copy, Debug)]
pub enum EscapeOrStart {
    Escape,
    Start,
}
pub type OrEscapeOrStart<T> = Result<T, EscapeOrStart>;

#[macro_export]
macro_rules! lens {
    ($input:ty[$field:ident]: $output:ty) => {{
        fn get(state: &$input) -> &$output {
            &state.$field
        }
        fn get_mut(state: &mut $input) -> &mut $output {
            &mut state.$field
        }
        LensFns::new(get, get_mut)
    }};
}

#[macro_export]
macro_rules! many {
    ($($items:expr),* $(,)* ) => {
        $crate::control_flow::many([
            $($crate::control_flow::cf($items)),*
        ])
    };
}

pub use crate::{lens, many};