std_ext/
vec.rs

1use std::ops::Deref;
2
3pub trait VecExt<T> {
4    fn any<F: Fn(&T) -> bool>(&self, f: F) -> bool;
5    fn fold<F, U>(&self, f: F, init: U) -> U
6    where
7        F: Fn(U, &T) -> U;
8    fn into_first(self) -> Option<T>;
9    fn into_last(self) -> Option<T>;
10    fn recollect<U: From<T>>(self) -> Vec<U>;
11    fn merge_grouped<U>(
12        &mut self,
13        children: Vec<U>,
14        matcher: impl Fn(&T, &U) -> bool,
15        merger: impl Fn(&mut T, U),
16    );
17}
18
19pub trait DerefVec<T>
20where
21    T: Deref,
22{
23    fn includes(&self, item: &T::Target) -> bool;
24}
25
26impl<T> VecExt<T> for Vec<T> {
27    fn any<F: Fn(&T) -> bool>(&self, f: F) -> bool {
28        self.iter().any(f)
29    }
30
31    fn fold<F, U>(&self, f: F, init: U) -> U
32    where
33        F: Fn(U, &T) -> U,
34    {
35        self.iter().fold(init, f)
36    }
37
38    fn into_first(self) -> Option<T> {
39        self.into_iter().next()
40    }
41
42    fn into_last(mut self) -> Option<T> {
43        if self.is_empty() {
44            return None;
45        }
46        Some(self.remove(self.len() - 1))
47    }
48    fn recollect<U: From<T>>(self) -> Vec<U> {
49        self.into_iter().map(Into::into).collect()
50    }
51
52    fn merge_grouped<U>(
53        &mut self,
54        children: Vec<U>,
55        matcher: impl Fn(&T, &U) -> bool,
56        merger: impl Fn(&mut T, U),
57    ) {
58        let mut it = self.iter_mut().peekable();
59        for child in children {
60            while !matcher(it.peek().unwrap(), &child) {
61                it.next();
62            }
63            let current = it.peek_mut().unwrap();
64            merger(current, child);
65        }
66    }
67}
68
69impl<T> DerefVec<T> for Vec<T>
70where
71    T: Deref + PartialEq<T::Target>,
72{
73    fn includes(&self, item: &T::Target) -> bool {
74        self.iter().any(|i| i == item)
75    }
76}
77
78#[macro_export]
79macro_rules! vec_into {
80    ($(($($item:expr),*)),* $(,)?) => {
81        {
82            let mut v = Vec::new();
83            $(v.push(($($item.into()),*));)*
84            v
85        }
86    };
87    ($($item:expr),* $(,)?) => {
88        {
89            let mut v = Vec::new();
90            $(v.push($item.into());)*
91            v
92        }
93    };
94}
95
96#[cfg(test)]
97mod tests {
98    use super::*;
99
100    #[test]
101    fn test_deref() {
102        let s = vec!["a".to_string(), "b".to_string()];
103        assert!(s.includes("a"));
104    }
105
106    #[test]
107    fn test_vec_into() {
108        let s: Vec<String> = vec_into!["a", "b"];
109        assert_eq!(s, vec!["a".to_string(), "b".to_string()]);
110    }
111}