diffus/diffable_impls/
map.rs

1use crate::{
2    edit::{map, Edit},
3    Diffable,
4};
5
6macro_rules! map_impl {
7    ($(($typ:ident, $key_constraint:ident)),*) => {
8        $(
9            impl<'a, K: Eq + $key_constraint + 'a, V: Diffable<'a> + 'a> Diffable<'a> for $typ<K, V> {
10                type Diff = $typ<&'a K, map::Edit<'a, V>>;
11
12                fn diff(&'a self, other: &'a Self) -> Edit<Self> {
13                    let intersection = self
14                        .iter()
15                        .filter_map(|(k, v)| Some((k, (v, other.get(k)?))));
16
17                    let unique_self = self.iter().filter(|(k, _)| !other.contains_key(*k));
18
19                    let unique_other = other.iter().filter(|(k, _)| !self.contains_key(*k));
20
21                    let value_diffs = unique_other
22                        .map(|(k, v)| (k, map::Edit::Insert(v)))
23                        .chain(unique_self.map(|(k, v)| (k, map::Edit::Remove(v))))
24                        .chain(intersection.map(|(k, (self_v, other_v))| (k, self_v.diff(other_v).into())))
25                        .collect::<$typ<_, _>>();
26
27                    if value_diffs.values().any(|v| !v.is_copy()) {
28                        Edit::Change(value_diffs)
29                    } else {
30                        Edit::Copy(self)
31                    }
32                }
33            }
34        )*
35    }
36}
37
38use std::{
39    collections::{BTreeMap, HashMap},
40    hash::Hash,
41};
42map_impl! {
43    (BTreeMap, Ord),
44    (HashMap, Hash)
45}
46
47#[cfg(feature = "indexmap-impl")]
48use indexmap::IndexMap;
49#[cfg(feature = "indexmap-impl")]
50map_impl! { (IndexMap, Hash) }
51
52#[cfg(test)]
53mod tests {
54    use super::*;
55
56    #[test]
57    fn example() {
58        let unity: std::collections::HashMap<_, _> =
59            [(1, 1), (2, 2), (3, 3)].iter().cloned().collect();
60        let not_unity: std::collections::HashMap<_, _> =
61            [(1, 1), (2, 3), (4, 4)].iter().cloned().collect();
62
63        if let Edit::Change(diff) = unity.diff(&not_unity) {
64            assert!(diff[&1].is_copy());
65            assert_eq!(diff[&2].change().unwrap(), &(&2, &3));
66            assert!(diff[&3].is_remove());
67            assert_eq!(diff[&4].insert().unwrap(), &4);
68        } else {
69            unreachable!()
70        }
71    }
72}
diffus/diffable_impls/map.rs

diffus/diffable_impls/
map.rs
