Coverage Report

Created: 2025-11-24 06:31

next uncovered line (L), next uncovered region (R), next uncovered branch (B)
/rust/registry/src/index.crates.io-1949cf8c6b5b557f/indexmap-2.12.1/src/set/slice.rs
Line
Count
Source
1
use super::{Bucket, IndexSet, IntoIter, Iter};
2
use crate::util::{slice_eq, try_simplify_range};
3
4
use alloc::boxed::Box;
5
use alloc::vec::Vec;
6
use core::cmp::Ordering;
7
use core::fmt;
8
use core::hash::{Hash, Hasher};
9
use core::ops::{self, Bound, Index, RangeBounds};
10
11
/// A dynamically-sized slice of values in an [`IndexSet`].
12
///
13
/// This supports indexed operations much like a `[T]` slice,
14
/// but not any hashed operations on the values.
15
///
16
/// Unlike `IndexSet`, `Slice` does consider the order for [`PartialEq`]
17
/// and [`Eq`], and it also implements [`PartialOrd`], [`Ord`], and [`Hash`].
18
#[repr(transparent)]
19
pub struct Slice<T> {
20
    pub(crate) entries: [Bucket<T>],
21
}
22
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// SAFETY: `Slice<T>` is a transparent wrapper around `[Bucket<T>]`,
24
// and reference lifetimes are bound together in function signatures.
25
#[allow(unsafe_code)]
26
impl<T> Slice<T> {
27
0
    pub(super) const fn from_slice(entries: &[Bucket<T>]) -> &Self {
28
0
        unsafe { &*(entries as *const [Bucket<T>] as *const Self) }
29
0
    }
30
31
0
    pub(super) fn from_boxed(entries: Box<[Bucket<T>]>) -> Box<Self> {
32
0
        unsafe { Box::from_raw(Box::into_raw(entries) as *mut Self) }
33
0
    }
34
35
0
    fn into_boxed(self: Box<Self>) -> Box<[Bucket<T>]> {
36
0
        unsafe { Box::from_raw(Box::into_raw(self) as *mut [Bucket<T>]) }
37
0
    }
38
}
39
40
impl<T> Slice<T> {
41
0
    pub(crate) fn into_entries(self: Box<Self>) -> Vec<Bucket<T>> {
42
0
        self.into_boxed().into_vec()
43
0
    }
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    /// Returns an empty slice.
46
0
    pub const fn new<'a>() -> &'a Self {
47
0
        Self::from_slice(&[])
48
0
    }
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    /// Return the number of elements in the set slice.
51
0
    pub const fn len(&self) -> usize {
52
0
        self.entries.len()
53
0
    }
54
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    /// Returns true if the set slice contains no elements.
56
0
    pub const fn is_empty(&self) -> bool {
57
0
        self.entries.is_empty()
58
0
    }
59
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    /// Get a value by index.
61
    ///
62
    /// Valid indices are `0 <= index < self.len()`.
63
0
    pub fn get_index(&self, index: usize) -> Option<&T> {
64
0
        self.entries.get(index).map(Bucket::key_ref)
65
0
    }
66
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    /// Returns a slice of values in the given range of indices.
68
    ///
69
    /// Valid indices are `0 <= index < self.len()`.
70
0
    pub fn get_range<R: RangeBounds<usize>>(&self, range: R) -> Option<&Self> {
71
0
        let range = try_simplify_range(range, self.entries.len())?;
72
0
        self.entries.get(range).map(Self::from_slice)
73
0
    }
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    /// Get the first value.
76
0
    pub fn first(&self) -> Option<&T> {
77
0
        self.entries.first().map(Bucket::key_ref)
78
0
    }
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    /// Get the last value.
81
0
    pub fn last(&self) -> Option<&T> {
82
0
        self.entries.last().map(Bucket::key_ref)
83
0
    }
84
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    /// Divides one slice into two at an index.
86
    ///
87
    /// ***Panics*** if `index > len`.
88
    #[track_caller]
89
0
    pub fn split_at(&self, index: usize) -> (&Self, &Self) {
90
0
        let (first, second) = self.entries.split_at(index);
91
0
        (Self::from_slice(first), Self::from_slice(second))
92
0
    }
93
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    /// Returns the first value and the rest of the slice,
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    /// or `None` if it is empty.
96
0
    pub fn split_first(&self) -> Option<(&T, &Self)> {
97
0
        if let [first, rest @ ..] = &self.entries {
98
0
            Some((&first.key, Self::from_slice(rest)))
99
        } else {
100
0
            None
101
        }
102
0
    }
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    /// Returns the last value and the rest of the slice,
105
    /// or `None` if it is empty.
106
0
    pub fn split_last(&self) -> Option<(&T, &Self)> {
107
0
        if let [rest @ .., last] = &self.entries {
108
0
            Some((&last.key, Self::from_slice(rest)))
109
        } else {
110
0
            None
111
        }
112
0
    }
113
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    /// Return an iterator over the values of the set slice.
115
0
    pub fn iter(&self) -> Iter<'_, T> {
116
0
        Iter::new(&self.entries)
117
0
    }
118
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    /// Search over a sorted set for a value.
120
    ///
121
    /// Returns the position where that value is present, or the position where it can be inserted
122
    /// to maintain the sort. See [`slice::binary_search`] for more details.
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    ///
124
    /// Computes in **O(log(n))** time, which is notably less scalable than looking the value up in
125
    /// the set this is a slice from using [`IndexSet::get_index_of`], but this can also position
126
    /// missing values.
127
0
    pub fn binary_search(&self, x: &T) -> Result<usize, usize>
128
0
    where
129
0
        T: Ord,
130
    {
131
0
        self.binary_search_by(|p| p.cmp(x))
132
0
    }
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    /// Search over a sorted set with a comparator function.
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    ///
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    /// Returns the position where that value is present, or the position where it can be inserted
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    /// to maintain the sort. See [`slice::binary_search_by`] for more details.
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    ///
139
    /// Computes in **O(log(n))** time.
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    #[inline]
141
0
    pub fn binary_search_by<'a, F>(&'a self, mut f: F) -> Result<usize, usize>
142
0
    where
143
0
        F: FnMut(&'a T) -> Ordering,
144
    {
145
0
        self.entries.binary_search_by(move |a| f(&a.key))
146
0
    }
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    /// Search over a sorted set with an extraction function.
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    ///
150
    /// Returns the position where that value is present, or the position where it can be inserted
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    /// to maintain the sort. See [`slice::binary_search_by_key`] for more details.
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    ///
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    /// Computes in **O(log(n))** time.
154
    #[inline]
155
0
    pub fn binary_search_by_key<'a, B, F>(&'a self, b: &B, mut f: F) -> Result<usize, usize>
156
0
    where
157
0
        F: FnMut(&'a T) -> B,
158
0
        B: Ord,
159
    {
160
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        self.binary_search_by(|k| f(k).cmp(b))
161
0
    }
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    /// Checks if the values of this slice are sorted.
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    #[inline]
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0
    pub fn is_sorted(&self) -> bool
166
0
    where
167
0
        T: PartialOrd,
168
    {
169
0
        self.entries.is_sorted_by(|a, b| a.key <= b.key)
170
0
    }
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    /// Checks if this slice is sorted using the given comparator function.
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    #[inline]
174
0
    pub fn is_sorted_by<'a, F>(&'a self, mut cmp: F) -> bool
175
0
    where
176
0
        F: FnMut(&'a T, &'a T) -> bool,
177
    {
178
0
        self.entries.is_sorted_by(move |a, b| cmp(&a.key, &b.key))
179
0
    }
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    /// Checks if this slice is sorted using the given sort-key function.
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    #[inline]
183
0
    pub fn is_sorted_by_key<'a, F, K>(&'a self, mut sort_key: F) -> bool
184
0
    where
185
0
        F: FnMut(&'a T) -> K,
186
0
        K: PartialOrd,
187
    {
188
0
        self.entries.is_sorted_by_key(move |a| sort_key(&a.key))
189
0
    }
190
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    /// Returns the index of the partition point of a sorted set according to the given predicate
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    /// (the index of the first element of the second partition).
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    ///
194
    /// See [`slice::partition_point`] for more details.
195
    ///
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    /// Computes in **O(log(n))** time.
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    #[must_use]
198
0
    pub fn partition_point<P>(&self, mut pred: P) -> usize
199
0
    where
200
0
        P: FnMut(&T) -> bool,
201
    {
202
0
        self.entries.partition_point(move |a| pred(&a.key))
203
0
    }
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}
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impl<'a, T> IntoIterator for &'a Slice<T> {
207
    type IntoIter = Iter<'a, T>;
208
    type Item = &'a T;
209
210
0
    fn into_iter(self) -> Self::IntoIter {
211
0
        self.iter()
212
0
    }
213
}
214
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impl<T> IntoIterator for Box<Slice<T>> {
216
    type IntoIter = IntoIter<T>;
217
    type Item = T;
218
219
0
    fn into_iter(self) -> Self::IntoIter {
220
0
        IntoIter::new(self.into_entries())
221
0
    }
222
}
223
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impl<T> Default for &'_ Slice<T> {
225
0
    fn default() -> Self {
226
0
        Slice::from_slice(&[])
227
0
    }
228
}
229
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impl<T> Default for Box<Slice<T>> {
231
0
    fn default() -> Self {
232
0
        Slice::from_boxed(Box::default())
233
0
    }
234
}
235
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impl<T: Clone> Clone for Box<Slice<T>> {
237
0
    fn clone(&self) -> Self {
238
0
        Slice::from_boxed(self.entries.to_vec().into_boxed_slice())
239
0
    }
240
}
241
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impl<T: Copy> From<&Slice<T>> for Box<Slice<T>> {
243
0
    fn from(slice: &Slice<T>) -> Self {
244
0
        Slice::from_boxed(Box::from(&slice.entries))
245
0
    }
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}
247
248
impl<T: fmt::Debug> fmt::Debug for Slice<T> {
249
0
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
250
0
        f.debug_list().entries(self).finish()
251
0
    }
252
}
253
254
impl<T, U> PartialEq<Slice<U>> for Slice<T>
255
where
256
    T: PartialEq<U>,
257
{
258
0
    fn eq(&self, other: &Slice<U>) -> bool {
259
0
        slice_eq(&self.entries, &other.entries, |b1, b2| b1.key == b2.key)
260
0
    }
261
}
262
263
impl<T, U> PartialEq<[U]> for Slice<T>
264
where
265
    T: PartialEq<U>,
266
{
267
0
    fn eq(&self, other: &[U]) -> bool {
268
0
        slice_eq(&self.entries, other, |b, o| b.key == *o)
269
0
    }
270
}
271
272
impl<T, U> PartialEq<Slice<U>> for [T]
273
where
274
    T: PartialEq<U>,
275
{
276
0
    fn eq(&self, other: &Slice<U>) -> bool {
277
0
        slice_eq(self, &other.entries, |o, b| *o == b.key)
278
0
    }
279
}
280
281
impl<T, U, const N: usize> PartialEq<[U; N]> for Slice<T>
282
where
283
    T: PartialEq<U>,
284
{
285
0
    fn eq(&self, other: &[U; N]) -> bool {
286
0
        <Self as PartialEq<[U]>>::eq(self, other)
287
0
    }
288
}
289
290
impl<T, const N: usize, U> PartialEq<Slice<U>> for [T; N]
291
where
292
    T: PartialEq<U>,
293
{
294
0
    fn eq(&self, other: &Slice<U>) -> bool {
295
0
        <[T] as PartialEq<Slice<U>>>::eq(self, other)
296
0
    }
297
}
298
299
impl<T: Eq> Eq for Slice<T> {}
300
301
impl<T: PartialOrd> PartialOrd for Slice<T> {
302
0
    fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
303
0
        self.iter().partial_cmp(other)
304
0
    }
305
}
306
307
impl<T: Ord> Ord for Slice<T> {
308
0
    fn cmp(&self, other: &Self) -> Ordering {
309
0
        self.iter().cmp(other)
310
0
    }
311
}
312
313
impl<T: Hash> Hash for Slice<T> {
314
0
    fn hash<H: Hasher>(&self, state: &mut H) {
315
0
        self.len().hash(state);
316
0
        for value in self {
317
0
            value.hash(state);
318
0
        }
319
0
    }
320
}
321
322
impl<T> Index<usize> for Slice<T> {
323
    type Output = T;
324
325
0
    fn index(&self, index: usize) -> &Self::Output {
326
0
        &self.entries[index].key
327
0
    }
328
}
329
330
// We can't have `impl<I: RangeBounds<usize>> Index<I>` because that conflicts with `Index<usize>`.
331
// Instead, we repeat the implementations for all the core range types.
332
macro_rules! impl_index {
333
    ($($range:ty),*) => {$(
334
        impl<T, S> Index<$range> for IndexSet<T, S> {
335
            type Output = Slice<T>;
336
337
0
            fn index(&self, range: $range) -> &Self::Output {
338
0
                Slice::from_slice(&self.as_entries()[range])
339
0
            }
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::Range<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeFrom<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeFull>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeInclusive<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeTo<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<core::ops::range::RangeToInclusive<usize>>>::index
Unexecuted instantiation: <indexmap::set::IndexSet<_, _> as core::ops::index::Index<(core::ops::range::Bound<usize>, core::ops::range::Bound<usize>)>>::index
340
        }
341
342
        impl<T> Index<$range> for Slice<T> {
343
            type Output = Self;
344
345
0
            fn index(&self, range: $range) -> &Self::Output {
346
0
                Slice::from_slice(&self.entries[range])
347
0
            }
Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::Range<usize>>>::index
Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeFrom<usize>>>::index
Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeFull>>::index
Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeInclusive<usize>>>::index
Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeTo<usize>>>::index
Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<core::ops::range::RangeToInclusive<usize>>>::index
Unexecuted instantiation: <indexmap::set::slice::Slice<_> as core::ops::index::Index<(core::ops::range::Bound<usize>, core::ops::range::Bound<usize>)>>::index
348
        }
349
    )*}
350
}
351
impl_index!(
352
    ops::Range<usize>,
353
    ops::RangeFrom<usize>,
354
    ops::RangeFull,
355
    ops::RangeInclusive<usize>,
356
    ops::RangeTo<usize>,
357
    ops::RangeToInclusive<usize>,
358
    (Bound<usize>, Bound<usize>)
359
);
360
361
#[cfg(test)]
362
mod tests {
363
    use super::*;
364
365
    #[test]
366
    fn slice_index() {
367
        fn check(vec_slice: &[i32], set_slice: &Slice<i32>, sub_slice: &Slice<i32>) {
368
            assert_eq!(set_slice as *const _, sub_slice as *const _);
369
            itertools::assert_equal(vec_slice, set_slice);
370
        }
371
372
        let vec: Vec<i32> = (0..10).map(|i| i * i).collect();
373
        let set: IndexSet<i32> = vec.iter().cloned().collect();
374
        let slice = set.as_slice();
375
376
        // RangeFull
377
        check(&vec[..], &set[..], &slice[..]);
378
379
        for i in 0usize..10 {
380
            // Index
381
            assert_eq!(vec[i], set[i]);
382
            assert_eq!(vec[i], slice[i]);
383
384
            // RangeFrom
385
            check(&vec[i..], &set[i..], &slice[i..]);
386
387
            // RangeTo
388
            check(&vec[..i], &set[..i], &slice[..i]);
389
390
            // RangeToInclusive
391
            check(&vec[..=i], &set[..=i], &slice[..=i]);
392
393
            // (Bound<usize>, Bound<usize>)
394
            let bounds = (Bound::Excluded(i), Bound::Unbounded);
395
            check(&vec[i + 1..], &set[bounds], &slice[bounds]);
396
397
            for j in i..=10 {
398
                // Range
399
                check(&vec[i..j], &set[i..j], &slice[i..j]);
400
            }
401
402
            for j in i..10 {
403
                // RangeInclusive
404
                check(&vec[i..=j], &set[i..=j], &slice[i..=j]);
405
            }
406
        }
407
    }
408
}