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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-30 03:57:31 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-30 03:57:31 +0000 |
commit | dc0db358abe19481e475e10c32149b53370f1a1c (patch) | |
tree | ab8ce99c4b255ce46f99ef402c27916055b899ee /vendor/indexmap/src/set/slice.rs | |
parent | Releasing progress-linux version 1.71.1+dfsg1-2~progress7.99u1. (diff) | |
download | rustc-dc0db358abe19481e475e10c32149b53370f1a1c.tar.xz rustc-dc0db358abe19481e475e10c32149b53370f1a1c.zip |
Merging upstream version 1.72.1+dfsg1.
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'vendor/indexmap/src/set/slice.rs')
-rw-r--r-- | vendor/indexmap/src/set/slice.rs | 278 |
1 files changed, 278 insertions, 0 deletions
diff --git a/vendor/indexmap/src/set/slice.rs b/vendor/indexmap/src/set/slice.rs new file mode 100644 index 000000000..608311d2d --- /dev/null +++ b/vendor/indexmap/src/set/slice.rs @@ -0,0 +1,278 @@ +use super::{Bucket, Entries, IndexSet, IntoIter, Iter}; +use crate::util::try_simplify_range; + +use alloc::boxed::Box; +use alloc::vec::Vec; +use core::cmp::Ordering; +use core::fmt; +use core::hash::{Hash, Hasher}; +use core::ops::{self, Bound, Index, RangeBounds}; + +/// A dynamically-sized slice of values in an `IndexSet`. +/// +/// This supports indexed operations much like a `[T]` slice, +/// but not any hashed operations on the values. +/// +/// Unlike `IndexSet`, `Slice` does consider the order for `PartialEq` +/// and `Eq`, and it also implements `PartialOrd`, `Ord`, and `Hash`. +#[repr(transparent)] +pub struct Slice<T> { + pub(crate) entries: [Bucket<T>], +} + +// SAFETY: `Slice<T>` is a transparent wrapper around `[Bucket<T>]`, +// and reference lifetimes are bound together in function signatures. +#[allow(unsafe_code)] +impl<T> Slice<T> { + pub(super) fn from_slice(entries: &[Bucket<T>]) -> &Self { + unsafe { &*(entries as *const [Bucket<T>] as *const Self) } + } + + pub(super) fn from_boxed(entries: Box<[Bucket<T>]>) -> Box<Self> { + unsafe { Box::from_raw(Box::into_raw(entries) as *mut Self) } + } + + fn into_boxed(self: Box<Self>) -> Box<[Bucket<T>]> { + unsafe { Box::from_raw(Box::into_raw(self) as *mut [Bucket<T>]) } + } +} + +impl<T> Slice<T> { + pub(crate) fn into_entries(self: Box<Self>) -> Vec<Bucket<T>> { + self.into_boxed().into_vec() + } + + /// Return the number of elements in the set slice. + pub fn len(&self) -> usize { + self.entries.len() + } + + /// Returns true if the set slice contains no elements. + pub fn is_empty(&self) -> bool { + self.entries.is_empty() + } + + /// Get a value by index. + /// + /// Valid indices are *0 <= index < self.len()* + pub fn get_index(&self, index: usize) -> Option<&T> { + self.entries.get(index).map(Bucket::key_ref) + } + + /// Returns a slice of values in the given range of indices. + /// + /// Valid indices are *0 <= index < self.len()* + pub fn get_range<R: RangeBounds<usize>>(&self, range: R) -> Option<&Self> { + let range = try_simplify_range(range, self.entries.len())?; + self.entries.get(range).map(Self::from_slice) + } + + /// Get the first value. + pub fn first(&self) -> Option<&T> { + self.entries.first().map(Bucket::key_ref) + } + + /// Get the last value. + pub fn last(&self) -> Option<&T> { + self.entries.last().map(Bucket::key_ref) + } + + /// Divides one slice into two at an index. + /// + /// ***Panics*** if `index > len`. + pub fn split_at(&self, index: usize) -> (&Self, &Self) { + let (first, second) = self.entries.split_at(index); + (Self::from_slice(first), Self::from_slice(second)) + } + + /// Returns the first value and the rest of the slice, + /// or `None` if it is empty. + pub fn split_first(&self) -> Option<(&T, &Self)> { + if let [first, rest @ ..] = &self.entries { + Some((&first.key, Self::from_slice(rest))) + } else { + None + } + } + + /// Returns the last value and the rest of the slice, + /// or `None` if it is empty. + pub fn split_last(&self) -> Option<(&T, &Self)> { + if let [rest @ .., last] = &self.entries { + Some((&last.key, Self::from_slice(rest))) + } else { + None + } + } + + /// Return an iterator over the values of the set slice. + pub fn iter(&self) -> Iter<'_, T> { + Iter::new(&self.entries) + } +} + +impl<'a, T> IntoIterator for &'a Slice<T> { + type IntoIter = Iter<'a, T>; + type Item = &'a T; + + fn into_iter(self) -> Self::IntoIter { + self.iter() + } +} + +impl<T> IntoIterator for Box<Slice<T>> { + type IntoIter = IntoIter<T>; + type Item = T; + + fn into_iter(self) -> Self::IntoIter { + IntoIter::new(self.into_entries()) + } +} + +impl<T> Default for &'_ Slice<T> { + fn default() -> Self { + Slice::from_slice(&[]) + } +} + +impl<T> Default for Box<Slice<T>> { + fn default() -> Self { + Slice::from_boxed(Box::default()) + } +} + +impl<T: Clone> Clone for Box<Slice<T>> { + fn clone(&self) -> Self { + Slice::from_boxed(self.entries.to_vec().into_boxed_slice()) + } +} + +impl<T: Copy> From<&Slice<T>> for Box<Slice<T>> { + fn from(slice: &Slice<T>) -> Self { + Slice::from_boxed(Box::from(&slice.entries)) + } +} + +impl<T: fmt::Debug> fmt::Debug for Slice<T> { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.debug_list().entries(self).finish() + } +} + +impl<T: PartialEq> PartialEq for Slice<T> { + fn eq(&self, other: &Self) -> bool { + self.len() == other.len() && self.iter().eq(other) + } +} + +impl<T: Eq> Eq for Slice<T> {} + +impl<T: PartialOrd> PartialOrd for Slice<T> { + fn partial_cmp(&self, other: &Self) -> Option<Ordering> { + self.iter().partial_cmp(other) + } +} + +impl<T: Ord> Ord for Slice<T> { + fn cmp(&self, other: &Self) -> Ordering { + self.iter().cmp(other) + } +} + +impl<T: Hash> Hash for Slice<T> { + fn hash<H: Hasher>(&self, state: &mut H) { + self.len().hash(state); + for value in self { + value.hash(state); + } + } +} + +impl<T> Index<usize> for Slice<T> { + type Output = T; + + fn index(&self, index: usize) -> &Self::Output { + &self.entries[index].key + } +} + +// We can't have `impl<I: RangeBounds<usize>> Index<I>` because that conflicts with `Index<usize>`. +// Instead, we repeat the implementations for all the core range types. +macro_rules! impl_index { + ($($range:ty),*) => {$( + impl<T, S> Index<$range> for IndexSet<T, S> { + type Output = Slice<T>; + + fn index(&self, range: $range) -> &Self::Output { + Slice::from_slice(&self.as_entries()[range]) + } + } + + impl<T> Index<$range> for Slice<T> { + type Output = Self; + + fn index(&self, range: $range) -> &Self::Output { + Slice::from_slice(&self.entries[range]) + } + } + )*} +} +impl_index!( + ops::Range<usize>, + ops::RangeFrom<usize>, + ops::RangeFull, + ops::RangeInclusive<usize>, + ops::RangeTo<usize>, + ops::RangeToInclusive<usize>, + (Bound<usize>, Bound<usize>) +); + +#[cfg(test)] +mod tests { + use super::*; + use alloc::vec::Vec; + + #[test] + fn slice_index() { + fn check(vec_slice: &[i32], set_slice: &Slice<i32>, sub_slice: &Slice<i32>) { + assert_eq!(set_slice as *const _, sub_slice as *const _); + itertools::assert_equal(vec_slice, set_slice); + } + + let vec: Vec<i32> = (0..10).map(|i| i * i).collect(); + let set: IndexSet<i32> = vec.iter().cloned().collect(); + let slice = set.as_slice(); + + // RangeFull + check(&vec[..], &set[..], &slice[..]); + + for i in 0usize..10 { + // Index + assert_eq!(vec[i], set[i]); + assert_eq!(vec[i], slice[i]); + + // RangeFrom + check(&vec[i..], &set[i..], &slice[i..]); + + // RangeTo + check(&vec[..i], &set[..i], &slice[..i]); + + // RangeToInclusive + check(&vec[..=i], &set[..=i], &slice[..=i]); + + // (Bound<usize>, Bound<usize>) + let bounds = (Bound::Excluded(i), Bound::Unbounded); + check(&vec[i + 1..], &set[bounds], &slice[bounds]); + + for j in i..=10 { + // Range + check(&vec[i..j], &set[i..j], &slice[i..j]); + } + + for j in i..10 { + // RangeInclusive + check(&vec[i..=j], &set[i..=j], &slice[i..=j]); + } + } + } +} |