line_ui/element/
impls.rs

1/*
2 * Copyright (c) 2025 Jasmine Tai. All rights reserved.
3 */
4
5use crate::element::Element;
6use crate::render::RenderChunk;
7
8impl<E: Element + ?Sized> Element for &'_ E {
9    fn width(&self) -> usize {
10        (*self).width()
11    }
12
13    fn render(&self) -> impl DoubleEndedIterator<Item = RenderChunk<'_>> {
14        (*self).render()
15    }
16}
17
18impl<E: Element> Element for [E] {
19    fn width(&self) -> usize {
20        self.iter().map(|e| e.width()).sum()
21    }
22
23    fn render(&self) -> impl DoubleEndedIterator<Item = RenderChunk<'_>> {
24        self.iter().flat_map(|e| e.render())
25    }
26}
27
28impl<E: Element, const N: usize> Element for [E; N] {
29    fn width(&self) -> usize {
30        self.iter().map(|e| e.width()).sum()
31    }
32
33    fn render(&self) -> impl DoubleEndedIterator<Item = RenderChunk<'_>> {
34        self.iter().flat_map(|e| e.render())
35    }
36}
37
38impl<E: Element> Element for Option<E> {
39    fn width(&self) -> usize {
40        match self {
41            Some(inner) => inner.width(),
42            None => 0,
43        }
44    }
45
46    fn render(&self) -> impl DoubleEndedIterator<Item = RenderChunk<'_>> {
47        self.iter().flat_map(|e| e.render())
48    }
49}
50
51impl Element for () {
52    fn width(&self) -> usize {
53        0
54    }
55
56    fn render(&self) -> impl DoubleEndedIterator<Item = RenderChunk<'_>> {
57        std::iter::empty()
58    }
59}
60
61macro_rules! impl_element_for_tuple {
62    ( A $( $t:ident )* , 0 $( $n:tt )* ) => {
63        impl<A $(, $t)*> Element for (A, $($t),*)
64        where
65            A: Element,
66            $($t: Element,)*
67        {
68            fn width(&self) -> usize {
69                self.0.width()
70                $(+ self.$n.width())*
71            }
72
73            fn render(&self) -> impl DoubleEndedIterator<Item = RenderChunk<'_>> {
74                self.0.render()
75                $(.chain(self.$n.render()))*
76            }
77        }
78    };
79}
80
81impl_element_for_tuple!(A, 0);
82impl_element_for_tuple!(A B, 0 1);
83impl_element_for_tuple!(A B C, 0 1 2);
84impl_element_for_tuple!(A B C D, 0 1 2 3);
85impl_element_for_tuple!(A B C D E, 0 1 2 3 4);
86impl_element_for_tuple!(A B C D E F, 0 1 2 3 4 5);
87impl_element_for_tuple!(A B C D E F G, 0 1 2 3 4 5 6);
88impl_element_for_tuple!(A B C D E F G H, 0 1 2 3 4 5 6 7);
89impl_element_for_tuple!(A B C D E F G H I, 0 1 2 3 4 5 6 7 8);
90impl_element_for_tuple!(A B C D E F G H I J, 0 1 2 3 4 5 6 7 8 9);
91
92#[cfg(test)]
93mod tests {
94    use crate::element::Gap;
95
96    use super::*;
97
98    fn is_element<E: Element + ?Sized>() {}
99
100    #[test]
101    fn element_impls() {
102        is_element::<[Gap]>();
103        is_element::<&[Gap]>();
104        is_element::<[Gap; 42]>();
105        is_element::<[&[Gap]; 4]>();
106        is_element::<((), (), (), (), (), (), (), Gap, (), ())>();
107    }
108}
line_ui/element/impls.rs

line_ui/element/
impls.rs
