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
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
//! Implementations for types from the `alloc` crate.
use crate::{Diffable, Leaf};
use alloc::{
borrow::{Cow, ToOwned},
boxed::Box,
collections::{BTreeMap, BTreeSet},
rc::Rc,
string::String,
sync::Arc,
vec::Vec,
};
leaf_deref! { String => str }
impl<T: Diffable + ?Sized> Diffable for Box<T> {
type Diff<'daft>
= <T as Diffable>::Diff<'daft>
where
T: 'daft;
fn diff<'daft>(&'daft self, other: &'daft Self) -> Self::Diff<'daft> {
(**self).diff(other)
}
}
impl<T: Diffable + ToOwned + ?Sized> Diffable for Cow<'_, T> {
type Diff<'daft>
= <T as Diffable>::Diff<'daft>
where
Self: 'daft;
fn diff<'daft>(&'daft self, other: &'daft Self) -> Self::Diff<'daft> {
self.as_ref().diff(other.as_ref())
}
}
impl<T: Diffable + ?Sized> Diffable for Arc<T> {
type Diff<'daft>
= <T as Diffable>::Diff<'daft>
where
T: 'daft;
fn diff<'daft>(&'daft self, other: &'daft Self) -> Self::Diff<'daft> {
(**self).diff(other)
}
}
impl<T: Diffable + ?Sized> Diffable for Rc<T> {
type Diff<'daft>
= <T as Diffable>::Diff<'daft>
where
T: 'daft;
fn diff<'daft>(&'daft self, other: &'daft Self) -> Self::Diff<'daft> {
(**self).diff(other)
}
}
map_diff!(
/// A diff of two [`BTreeMap`] instances.
///
/// The diff contains three elements:
///
/// - `common`: Entries that are present in both maps, with their values
/// stored as a [`Leaf`].
/// - `added`: Entries present in `after`, but not in `before`.
/// - `removed`: Entries present in `before`, but not in `after`.
///
/// If `V` implements `Eq`, `common` can be split into
/// [`unchanged`][Self::unchanged] and [`modified`][Self::modified] entries.
/// Additionally, if `V` implements [`Diffable`],
/// [`modified_diff`][Self::modified_diff] can be used to recursively diff
/// modified entries.
///
/// # Example
///
/// ```
/// # #[cfg(feature = "std")] {
/// use daft::{BTreeMapDiff, Diffable, Leaf};
/// use std::collections::BTreeMap;
///
/// let a: BTreeMap<usize, &str> =
/// [(0, "lorem"), (1, "ipsum"), (2, "dolor")].into_iter().collect();
/// let b: BTreeMap<usize, &str> =
/// [(1, "ipsum"), (2, "sit"), (3, "amet")].into_iter().collect();
///
/// let changes = a.diff(&b);
/// let expected = BTreeMapDiff {
/// // Keys are stored by reference and matched by equality.
/// common: [
/// (&1, Leaf { before: &"ipsum", after: &"ipsum" }),
/// (&2, Leaf { before: &"dolor", after: &"sit" }),
/// ].into_iter().collect(),
/// added: [(&3, &"amet")].into_iter().collect(),
/// removed: [(&0, &"lorem")].into_iter().collect(),
/// };
///
/// assert_eq!(changes, expected);
///
/// // If the values are `Eq`, it's also possible to get lists of
/// // modified and unchanged entries.
/// assert!(changes.is_unchanged(&1));
/// assert!(changes.is_modified(&2));
/// let unchanged = changes.unchanged().collect::<Vec<_>>();
/// let modified = changes.modified().collect::<Vec<_>>();
///
/// assert_eq!(unchanged, [(&1, &"ipsum")]);
/// assert_eq!(modified, [(&2, Leaf { before: &"dolor", after: &"sit" })]);
/// # }
/// ```
BTreeMap, Ord
);
set_diff!(
/// A diff of two [`BTreeSet`] instances.
///
/// The diff contains three elements:
///
/// - `common`: Entries that are present in both sets.
/// - `added`: Entries present in `after`, but not in `before`.
/// - `removed`: Entries present in `before`, but not in `after`.
///
/// # Example
///
/// ```
/// # #[cfg(feature = "std")] {
/// use daft::{BTreeSetDiff, Diffable};
/// use std::collections::BTreeSet;
///
/// let a: BTreeSet<usize> = [0, 1].into_iter().collect();
/// let b: BTreeSet<usize> = [1, 2].into_iter().collect();
///
/// let changes = a.diff(&b);
/// let expected = BTreeSetDiff {
/// // Entries are stored by reference and matched by equality.
/// common: [&1].into_iter().collect(),
/// added: [&2].into_iter().collect(),
/// removed: [&0].into_iter().collect(),
/// };
///
/// assert_eq!(changes, expected);
/// # }
/// ```
BTreeSet, Ord
);
/// Treat Vecs as Leafs
//
// We plan to add opt in diff functionality: set-like, reordered, etc...
impl<T: Diffable> Diffable for Vec<T> {
type Diff<'daft>
= Leaf<&'daft [T]>
where
T: 'daft;
fn diff<'daft>(&'daft self, other: &'daft Self) -> Self::Diff<'daft> {
Leaf { before: self, after: other }
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn btree_set_diff() {
let a: BTreeSet<_> = [0, 1, 2, 3, 4, 5].into_iter().collect();
let b: BTreeSet<_> = [3, 4, 5, 6, 7, 8].into_iter().collect();
let changes = a.diff(&b);
let expected = BTreeSetDiff {
added: [&6, &7, &8].into_iter().collect(),
removed: [&0, &1, &2].into_iter().collect(),
common: [&3, &4, &5].into_iter().collect(),
};
assert_eq!(expected, changes);
}
#[test]
fn btree_map_diff() {
let a: BTreeMap<_, _> = [(0, 1), (1, 1), (2, 1)].into_iter().collect();
let b: BTreeMap<_, _> = [(0, 2), (2, 1), (3, 1)].into_iter().collect();
let changes = a.diff(&b);
let expected = BTreeMapDiff {
common: [
(&0, Leaf { before: &1, after: &2 }),
(&2, Leaf { before: &1, after: &1 }),
]
.into_iter()
.collect(),
added: [(&3, &1)].into_iter().collect(),
removed: [(&1, &1)].into_iter().collect(),
};
assert_eq!(changes, expected);
// Ensure that keys don't need to be Diffable, and values don't need to
// be Eq or Diffable.
#[derive(Debug, PartialEq, Eq, PartialOrd, Ord)]
struct K(i32);
#[derive(Debug)]
#[expect(dead_code)]
struct V(f64);
let floats_a: BTreeMap<K, V> =
[(K(0), V(1.0)), (K(1), V(1.0)), (K(2), V(1.0))]
.into_iter()
.collect();
let floats_b: BTreeMap<K, V> =
[(K(0), V(2.0)), (K(2), V(1.0)), (K(3), V(1.0))]
.into_iter()
.collect();
let diff = floats_a.diff(&floats_b);
assert_eq!(diff.added.keys().copied().collect::<Vec<_>>(), [&K(3)]);
assert_eq!(diff.removed.keys().copied().collect::<Vec<_>>(), [&K(1)]);
assert_eq!(
diff.common.keys().copied().collect::<Vec<_>>(),
[&K(0), &K(2)]
);
}
}