hash_chain/
set.rs

1use std::{borrow::Borrow, collections::HashSet, hash::Hash, mem::replace};
2
3pub struct ChainSet<T> {
4    pub(crate) sets: Vec<HashSet<T>>,
5}
6
7impl<T: Hash + Eq> ChainSet<T> {
8    pub fn new(set: HashSet<T>) -> Self {
9        Self { sets: vec![set] }
10    }
11
12    pub fn insert(&mut self, value: T) -> bool {
13        if let Some(set) = self.sets.last_mut() {
14            set.insert(value)
15        } else {
16            let mut set = HashSet::new();
17            set.insert(value);
18            self.sets.push(set);
19            false
20        }
21    }
22
23    pub fn get<Q: ?Sized>(&self, value: &Q) -> Option<&T>
24    where
25        T: Borrow<Q>,
26        Q: Hash + Eq,
27    {
28        for set in self.sets.iter().rev() {
29            if let Some(v) = set.get(value) {
30                return Some(v);
31            }
32        }
33        None
34    }
35
36    pub fn new_child(&mut self) {
37        self.sets.push(HashSet::new());
38    }
39
40    pub fn new_child_with(&mut self, map: HashSet<T>) {
41        self.sets.push(map);
42    }
43
44    pub fn remove_child(&mut self) -> Option<HashSet<T>> {
45        if self.sets.len() == 1 {
46            let ret = replace(&mut self.sets[0], HashSet::new());
47            Some(ret)
48        } else {
49            self.sets.pop()
50        }
51    }
52}
53
54impl<T: Hash + Eq> Default for ChainSet<T> {
55    fn default() -> Self {
56        Self {
57            sets: vec![HashSet::new()],
58        }
59    }
60}
61
62#[cfg(test)]
63mod test {
64    use super::*;
65    use std::default::Default;
66
67    #[test]
68    fn initialization() {
69        let mut test_set = HashSet::new();
70        test_set.insert("test");
71        let chain_set = ChainSet::new(test_set);
72
73        assert!(chain_set.sets.len() > 0);
74        assert_eq!(chain_set.sets[0].get("test"), Some(&"test"));
75    }
76
77    #[test]
78    fn initialization_default() {
79        let chain_set: ChainSet<()> = ChainSet::default();
80
81        assert!(chain_set.sets.len() > 0);
82        assert!(chain_set.sets[0].is_empty());
83    }
84
85    #[test]
86    fn insert() {
87        let mut chain_set = ChainSet::default();
88        assert!(chain_set.insert("test"));
89
90        assert_eq!(chain_set.sets[0].get("test"), Some(&"test"));
91    }
92
93    #[test]
94    fn get() {
95        let mut chain_set = ChainSet::default();
96        chain_set.insert("test");
97
98        assert_eq!(chain_set.get(&"test"), Some(&"test"));
99    }
100
101    #[test]
102    fn get_none() {
103        let chain_set: ChainSet<&str> = ChainSet::default();
104        assert_eq!(chain_set.get(&"test"), None);
105    }
106
107    #[test]
108    fn new_child() {
109        let mut chain_set = ChainSet::default();
110        chain_set.insert("test");
111        chain_set.new_child();
112        assert!(chain_set.sets.len() > 1);
113    }
114
115    #[test]
116    #[ignore]
117    fn scopes() {
118        let mut chain_set = ChainSet::default();
119        chain_set.insert("x");
120        chain_set.insert("y");
121        chain_set.new_child();
122        assert!(chain_set.insert("x"));
123    }
124
125    #[test]
126    fn remove_child() {
127        let mut chain_set = ChainSet::default();
128        chain_set.insert("x");
129        chain_set.insert("y");
130        chain_set.new_child();
131        chain_set.insert("x");
132        let ret = chain_set.remove_child().unwrap();
133        assert_eq!(ret.get("x"), Some(&"x"));
134        assert_eq!(chain_set.get("x"), Some(&"x"));
135    }
136
137    #[test]
138    fn remove_child_length_1() {
139        let mut chain_set = ChainSet::default();
140        chain_set.insert("x");
141        let _ = chain_set.remove_child();
142        assert_eq!(chain_set.get("x"), None);
143        assert!(chain_set.sets.len() == 1);
144    }
145}
hash_chain/set.rs

hash_chain/
set.rs
