23354375031

Committed 20 Mar 2026 05:19PM UTC coverage: 76.49% (-1.4%) from 77.85%

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Downgraded Criterion to 0.7.0

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/src/array/partial_array.rs

/*
 * SPDX-FileCopyrightText: 2025 Sebastiano Vigna
 *
 * SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later
 */

//! Immutable [partial array](PartialArray) implementations.

use std::marker::PhantomData;

use mem_dbg::*;
use value_traits::slices::SliceByValue;

use crate::bits::BitVec;
use crate::dict::EliasFanoBuilder;
use crate::dict::elias_fano::EliasFano;
use crate::panic_if_out_of_bounds;
use crate::rank_sel::{Rank9, SelectZeroAdaptConst};
use crate::traits::Backend;
use crate::traits::{BitVecOps, BitVecOpsMut};
use crate::traits::{RankUnchecked, SuccUnchecked};

// Rank9 is inherently u64-based, so the dense index must use u64 backing
// regardless of usize.
type DenseIndex = Rank9<BitVec<Box<[u64]>>>;

/// An internal index for sparse partial arrays.
///
/// We cannot use directly an [Elias–Fano](crate::dict::EliasFano) structure
/// because we need to keep track of the first invalid position; and we need to
/// keep track of the first invalid position because we want to implement just
/// [`SuccUnchecked`](crate::traits::SuccUnchecked) on the Elias–Fano structure,
/// because it requires just
/// [`SelectZeroUnchecked`](crate::traits::SelectZeroUnchecked), whereas
/// [`Succ`](crate::traits::Succ) would require
/// [`SelectUnchecked`](crate::traits::SelectUnchecked) as well.
#[doc(hidden)]
#[derive(Debug, Clone, MemDbg, MemSize)]
#[cfg_attr(feature = "epserde", derive(epserde::Epserde))]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct SparseIndex<D> {
    ef: EliasFano<u64, SelectZeroAdaptConst<BitVec<D>, Box<[usize]>, 12, 3>>,
    /// self.ef should not be queried for values >= self.first_invalid_position
    first_invalid_pos: usize,
}

/// Builder for creating an immutable partial array.
///
/// The builder allows you to specify the array length and then add
/// (position, value) pairs. Positions must be added in strictly
/// increasing order.
///
/// To get a builder you can use either [new_dense] or [new_sparse].
#[derive(Debug, Clone, MemDbg, MemSize)]
pub struct PartialArrayBuilder<T, B> {
    builder: B,
    values: Vec<T>,
    len: usize,
    min_next_pos: usize,
}

/// Creates a new builder for a dense partial array of the given length.
///
/// A dense partial array stores a bit vector of the given length to mark
/// which positions contain values, and uses ranking on this bit vector to
/// map positions to indices in a contiguous value array.
///
/// If your set of values is really sparse, consider using a
/// [sparse partial array](new_sparse).
///
/// # Examples
///
/// ```rust
/// # use sux::array::partial_array;
/// let mut builder = partial_array::new_dense(10);
/// builder.set(1, "foo");
/// builder.set(2, "hello");
/// builder.set(7, "world");
///
/// let array = builder.build();
/// assert_eq!(array.get(1), Some(&"foo"));
/// assert_eq!(array.get(2), Some(&"hello"));
/// assert_eq!(array.get(3), None);
/// assert_eq!(array.get(7), Some(&"world"));
/// ```
pub fn new_dense<T>(len: usize) -> PartialArrayBuilder<T, BitVec<Box<[u64]>>> {
    let n_of_words = len.div_ceil(64);
    // SAFETY: the backing has exactly enough words for len bits
    let bit_vec = unsafe { BitVec::from_raw_parts(vec![0u64; n_of_words].into_boxed_slice(), len) };
    PartialArrayBuilder {
        builder: bit_vec,
        values: vec![],
        len,
        min_next_pos: 0,
    }
}

impl<T> PartialArrayBuilder<T, BitVec<Box<[u64]>>> {
    /// Sets a value at the given position.
    ///
    /// The provided position must be greater than the last position set.
    pub fn set(&mut self, position: usize, value: T) {
        if position < self.min_next_pos {
            panic!(
                "Positions must be set in increasing order: got {} after {}",
                position,
                self.min_next_pos - 1
            );
        }
        panic_if_out_of_bounds!(position, self.len);

        // SAFETY: position < len
        unsafe {
            self.builder.set_unchecked(position, true);
        }
        self.values.push(value);
        self.min_next_pos = position + 1;
    }

    /// Builds the immutable dense partial array.
    pub fn build(self) -> PartialArray<T, Rank9<BitVec<Box<[u64]>>>> {
        let (bit_vec, values) = (self.builder, self.values);
        let rank9 = Rank9::new(bit_vec);
        let values = values.into_boxed_slice();

        PartialArray {
            index: rank9,
            values,
            _marker: PhantomData,
        }
    }
}

/// Creates a new builder for a sparse partial array of the given length.
///
/// A sparse partial array stores the non-empty positions of the array in an
/// [Elias-Fano](crate::dict::EliasFano) structure.
///
/// If your set of values is really dense, consider using a [dense partial
/// array](new_dense).
///
/// # Examples
///
/// ```rust
/// # use sux::array::partial_array;
/// let mut builder = partial_array::new_sparse(10, 3);
/// builder.set(1, "foo");
/// builder.set(2, "hello");
/// builder.set(7, "world");
///
/// let array = builder.build();
/// assert_eq!(array.get(1), Some(&"foo"));
/// assert_eq!(array.get(2), Some(&"hello"));
/// assert_eq!(array.get(3), None);
/// assert_eq!(array.get(7), Some(&"world"));
/// ```
///
/// Note that you must specify the number of values in advance.
pub fn new_sparse<T>(len: usize, num_values: usize) -> PartialArrayBuilder<T, EliasFanoBuilder> {
    PartialArrayBuilder {
        builder: EliasFanoBuilder::new(num_values, len as u64),
        values: vec![],
        len,
        min_next_pos: 0,
    }
}

impl<T> PartialArrayBuilder<T, EliasFanoBuilder> {
    /// Sets a value at the given position.
    ///
    /// The provided position must be greater than the last position
    /// set.
    pub fn set(&mut self, position: usize, value: T) {
        if position < self.min_next_pos {
            panic!(
                "Positions must be set in increasing order: got {} after {}",
                position,
                self.min_next_pos - 1
            );
        }
        panic_if_out_of_bounds!(position, self.len);
        // SAFETY: conditions have been just checked
        unsafe { self.builder.push_unchecked(position as u64) };
        self.values.push(value);
        self.min_next_pos = position + 1;
    }

    /// Builds the immutable sparse partial array.
    pub fn build(self) -> PartialArray<T, SparseIndex<Box<[usize]>>> {
        let (builder, values) = (self.builder, self.values);
        let ef_dict = builder.build_with_dict();
        let values = values.into_boxed_slice();

        PartialArray {
            index: SparseIndex {
                ef: ef_dict,
                first_invalid_pos: self.min_next_pos,
            },
            values,
            _marker: PhantomData,
        }
    }
}

/// Extends the builder with an iterator of (position, value) pairs.
///
/// Position must be in strictly increasing order. The first returned
/// position must be greater than the last position set.
impl<T> Extend<(usize, T)> for PartialArrayBuilder<T, BitVec<Box<[u64]>>> {
    fn extend<I: IntoIterator<Item = (usize, T)>>(&mut self, iter: I) {
        for (pos, val) in iter {
            self.set(pos, val);
        }
    }
}

/// Extends the builder with an iterator of (position, value) pairs.
///
/// Position must be in strictly increasing order. The first returned
/// position must be greater than the last position set.
impl<T> Extend<(usize, T)> for PartialArrayBuilder<T, EliasFanoBuilder> {
    fn extend<I: IntoIterator<Item = (usize, T)>>(&mut self, iter: I) {
        for (pos, val) in iter {
            self.set(pos, val);
        }
    }
}

/// An immutable partial array that supports efficient queries
/// in compacted storage.
///
/// This structure stores a *partial array*—an array in which only
/// some positions contain values. There is a [dense](new_dense)
/// and a [sparse](new_sparse) implementation with different
/// space/time trade-offs.
///
/// For convenience, this structure implements [`SliceByValue`].
///
/// See [`PartialArrayBuilder`] for details on how to create a partial array.
#[derive(Debug, Clone, MemDbg, MemSize)]
#[cfg_attr(feature = "epserde", derive(epserde::Epserde))]
#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
pub struct PartialArray<T, P, V: AsRef<[T]> = Box<[T]>> {
    index: P,
    values: V,
    _marker: PhantomData<T>,
}

impl<T, P, V: AsRef<[T]>> PartialArray<T, P, V> {
    /// Returns the number of values stored in the array.
    #[inline(always)]
    pub fn num_values(&self) -> usize {
        self.values.as_ref().len()
    }
}

impl<T, V: AsRef<[T]>> PartialArray<T, DenseIndex, V> {
    /// Returns the total length of the array.
    ///
    /// This is the length that was specified when creating the builder,
    /// not the number of values actually stored.
    #[inline(always)]
    pub fn len(&self) -> usize {
        self.index.len()
    }

    /// Returns true if the array length is 0.
    #[inline(always)]
    pub fn is_empty(&self) -> bool {
        self.len() == 0
    }

    /// Gets a reference to the value at the given position.
    ///
    /// Returns `Some(&value)` if a value is present at the position,
    /// or `None` if no value was stored there.
    ///
    /// # Examples
    ///
    /// ```rust
    /// # use sux::array::partial_array;
    /// let mut builder = partial_array::new_dense(10);
    /// builder.set(5, 42);
    ///
    /// let array = builder.build();
    /// assert_eq!(array.get(5), Some(&42));
    /// assert_eq!(array.get(6), None);
    /// ```
    pub fn get(&self, position: usize) -> Option<&T> {
        panic_if_out_of_bounds!(position, self.len());

        // SAFETY: we just checked
        unsafe { self.get_unchecked(position) }
    }

    /// # Safety
    ///
    /// position < len()
    pub unsafe fn get_unchecked(&self, position: usize) -> Option<&T> {
        // Check if there's a value at this position
        // SAFETY: position < len() guaranteed by caller
        if !unsafe { self.index.get_unchecked(position) } {
            return None;
        }

        // Use ranking to find the index in the values array
        // SAFETY: position < len() guaranteed by caller
        let value_index = unsafe { self.index.rank_unchecked(position) };

        // SAFETY: necessarily value_index < num_values().
        Some(unsafe { self.values.as_ref().get_unchecked(value_index) })
    }
}

impl<T, D: Backend<Word = usize> + AsRef<[usize]>, V: AsRef<[T]>>
    PartialArray<T, SparseIndex<D>, V>
{
    /// Returns the total length of the array.
    ///
    /// This is the length that was specified when creating the builder,
    /// not the number of values actually stored.
    #[inline(always)]
    pub fn len(&self) -> usize {
        self.index.ef.upper_bound() as usize
    }

    /// Returns true if the array len is 0.
    #[inline(always)]
    pub fn is_empty(&self) -> bool {
        self.index.ef.upper_bound() == 0
    }

    /// Gets a reference to the value at the given position.
    ///
    /// Returns `Some(&value)` if a value is present at the position,
    /// or `None` if no value was stored there.
    ///
    /// # Examples
    ///
    /// ```rust
    /// # use sux::array::partial_array;
    /// let mut builder = partial_array::new_sparse(10, 1);
    /// builder.set(5, 42);
    ///
    /// let array = builder.build();
    /// assert_eq!(array.get(5), Some(&42));
    /// assert_eq!(array.get(6), None);
    /// ```
    pub fn get(&self, position: usize) -> Option<&T> {
        panic_if_out_of_bounds!(position, self.len());

        // SAFETY: we just checked
        unsafe { self.get_unchecked(position) }
    }

    /// # Safety
    ///
    /// position < len()
    pub unsafe fn get_unchecked(&self, position: usize) -> Option<&T> {
        if position >= self.index.first_invalid_pos {
            return None;
        }
        // Check if there's a value at this position
        // SAFETY: position <= last set position
        let (index, pos) = unsafe { self.index.ef.succ_unchecked::<false>(position as u64) };

        if pos != position as u64 {
            None
        } else {
            // SAFETY: necessarily value_index < num values.
            Some(unsafe { self.values.as_ref().get_unchecked(index) })
        }
    }
}

/// Returns an option even when using `get_value_unchecked` because it should be safe to call
/// whenever `position < len()`.
impl<T: Clone, V: AsRef<[T]>> SliceByValue for PartialArray<T, DenseIndex, V> {
    type Value = Option<T>;

    fn len(&self) -> usize {
        self.len()
    }

    unsafe fn get_value_unchecked(&self, position: usize) -> Self::Value {
        // SAFETY: position < len() guaranteed by caller
        unsafe { self.get_unchecked(position) }.cloned()
    }
}

/// Returns an option even when using `get_value_unchecked` because it should be safe to call
/// whenever `position < len()`.
impl<T: Clone, D: Backend<Word = usize> + AsRef<[usize]>, V: AsRef<[T]>> SliceByValue
    for PartialArray<T, SparseIndex<D>, V>
{
    type Value = Option<T>;

    fn len(&self) -> usize {
        self.len()
    }

    unsafe fn get_value_unchecked(&self, position: usize) -> Self::Value {
        // SAFETY: position < len() guaranteed by caller
        unsafe { self.get_unchecked(position) }.cloned()
    }
}

1	/*
2	* SPDX-FileCopyrightText: 2025 Sebastiano Vigna
3	*
4	* SPDX-License-Identifier: Apache-2.0 OR LGPL-2.1-or-later
5	*/
6
7	//! Immutable [partial array](PartialArray) implementations.
8
9	use std::marker::PhantomData;
10
11	use mem_dbg::*;
12	use value_traits::slices::SliceByValue;
13
14	use crate::bits::BitVec;
15	use crate::dict::EliasFanoBuilder;
16	use crate::dict::elias_fano::EliasFano;
17	use crate::panic_if_out_of_bounds;
18	use crate::rank_sel::{Rank9, SelectZeroAdaptConst};
19	use crate::traits::Backend;
20	use crate::traits::{BitVecOps, BitVecOpsMut};
21	use crate::traits::{RankUnchecked, SuccUnchecked};
22
23	// Rank9 is inherently u64-based, so the dense index must use u64 backing
24	// regardless of usize.
25	type DenseIndex = Rank9<BitVec<Box<[u64]>>>;
26
27	/// An internal index for sparse partial arrays.
28	///
29	/// We cannot use directly an [Elias–Fano](crate::dict::EliasFano) structure
30	/// because we need to keep track of the first invalid position; and we need to
31	/// keep track of the first invalid position because we want to implement just
32	/// [`SuccUnchecked`](crate::traits::SuccUnchecked) on the Elias–Fano structure,
33	/// because it requires just
34	/// [`SelectZeroUnchecked`](crate::traits::SelectZeroUnchecked), whereas
35	/// [`Succ`](crate::traits::Succ) would require
36	/// [`SelectUnchecked`](crate::traits::SelectUnchecked) as well.
37	#[doc(hidden)]
38	#[derive(Debug, Clone, MemDbg, MemSize)]
39	#[cfg_attr(feature = "epserde", derive(epserde::Epserde))]
40	#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
41	pub struct SparseIndex<D> {
42	ef: EliasFano<u64, SelectZeroAdaptConst<BitVec<D>, Box<[usize]>, 12, 3>>,
43	/// self.ef should not be queried for values >= self.first_invalid_position
44	first_invalid_pos: usize,
45	}
46
47	/// Builder for creating an immutable partial array.
48	///
49	/// The builder allows you to specify the array length and then add
50	/// (position, value) pairs. Positions must be added in strictly
51	/// increasing order.
52	///
53	/// To get a builder you can use either [new_dense] or [new_sparse].
54	#[derive(Debug, Clone, MemDbg, MemSize)]
55	pub struct PartialArrayBuilder<T, B> {
56	builder: B,
57	values: Vec<T>,
58	len: usize,
59	min_next_pos: usize,
60	}
61
62	/// Creates a new builder for a dense partial array of the given length.
63	///
64	/// A dense partial array stores a bit vector of the given length to mark
65	/// which positions contain values, and uses ranking on this bit vector to
66	/// map positions to indices in a contiguous value array.
67	///
68	/// If your set of values is really sparse, consider using a
69	/// [sparse partial array](new_sparse).
70	///
71	/// # Examples
72	///
73	/// ```rust
74	/// # use sux::array::partial_array;
75	/// let mut builder = partial_array::new_dense(10);
76	/// builder.set(1, "foo");
77	/// builder.set(2, "hello");
78	/// builder.set(7, "world");
79	///
80	/// let array = builder.build();
81	/// assert_eq!(array.get(1), Some(&"foo"));
82	/// assert_eq!(array.get(2), Some(&"hello"));
83	/// assert_eq!(array.get(3), None);
84	/// assert_eq!(array.get(7), Some(&"world"));
85	/// ```
86	pub fn new_dense<T>(len: usize) -> PartialArrayBuilder<T, BitVec<Box<[u64]>>> {	6✔
87	let n_of_words = len.div_ceil(64);	18✔
88	// SAFETY: the backing has exactly enough words for len bits
89	let bit_vec = unsafe { BitVec::from_raw_parts(vec![0u64; n_of_words].into_boxed_slice(), len) };	36✔
90	PartialArrayBuilder {
91	builder: bit_vec,
92	values: vec![],	6✔
93	len,
94	min_next_pos: 0,
95	}
96	}
97
98	impl<T> PartialArrayBuilder<T, BitVec<Box<[u64]>>> {
99	/// Sets a value at the given position.
100	///
101	/// The provided position must be greater than the last position set.
102	pub fn set(&mut self, position: usize, value: T) {	7✔
103	if position < self.min_next_pos {	7✔
104	panic!(	1✔
105	"Positions must be set in increasing order: got {} after {}",	×
106	position,	×
107	self.min_next_pos - 1	1✔
108	);
109	}
110	panic_if_out_of_bounds!(position, self.len);	18✔
111
112	// SAFETY: position < len
113	unsafe {
114	self.builder.set_unchecked(position, true);	10✔
115	}
116	self.values.push(value);	15✔
117	self.min_next_pos = position + 1;	5✔
118	}
119
120	/// Builds the immutable dense partial array.
121	pub fn build(self) -> PartialArray<T, Rank9<BitVec<Box<[u64]>>>> {	4✔
122	let (bit_vec, values) = (self.builder, self.values);	12✔
123	let rank9 = Rank9::new(bit_vec);	12✔
124	let values = values.into_boxed_slice();	12✔
125
126	PartialArray {
127	index: rank9,
128	values,
129	_marker: PhantomData,
130	}
131	}
132	}
133
134	/// Creates a new builder for a sparse partial array of the given length.
135	///
136	/// A sparse partial array stores the non-empty positions of the array in an
137	/// [Elias-Fano](crate::dict::EliasFano) structure.
138	///
139	/// If your set of values is really dense, consider using a [dense partial
140	/// array](new_dense).
141	///
142	/// # Examples
143	///
144	/// ```rust
145	/// # use sux::array::partial_array;
146	/// let mut builder = partial_array::new_sparse(10, 3);
147	/// builder.set(1, "foo");
148	/// builder.set(2, "hello");
149	/// builder.set(7, "world");
150	///
151	/// let array = builder.build();
152	/// assert_eq!(array.get(1), Some(&"foo"));
153	/// assert_eq!(array.get(2), Some(&"hello"));
154	/// assert_eq!(array.get(3), None);
155	/// assert_eq!(array.get(7), Some(&"world"));
156	/// ```
157	///
158	/// Note that you must specify the number of values in advance.
159	pub fn new_sparse<T>(len: usize, num_values: usize) -> PartialArrayBuilder<T, EliasFanoBuilder> {	7✔
160	PartialArrayBuilder {
161	builder: EliasFanoBuilder::new(num_values, len as u64),	28✔
162	values: vec![],	7✔
163	len,
164	min_next_pos: 0,
165	}
166	}
167
168	impl<T> PartialArrayBuilder<T, EliasFanoBuilder> {
169	/// Sets a value at the given position.
170	///
171	/// The provided position must be greater than the last position
172	/// set.
173	pub fn set(&mut self, position: usize, value: T) {	10✔
174	if position < self.min_next_pos {	10✔
175	panic!(	1✔
176	"Positions must be set in increasing order: got {} after {}",	×
177	position,	×
178	self.min_next_pos - 1	1✔
179	);
180	}
181	panic_if_out_of_bounds!(position, self.len);	27✔
182	// SAFETY: conditions have been just checked
183	unsafe { self.builder.push_unchecked(position as u64) };	24✔
184	self.values.push(value);	24✔
185	self.min_next_pos = position + 1;	8✔
186	}
187
188	/// Builds the immutable sparse partial array.
189	pub fn build(self) -> PartialArray<T, SparseIndex<Box<[usize]>>> {	5✔
190	let (builder, values) = (self.builder, self.values);	15✔
191	let ef_dict = builder.build_with_dict();	15✔
192	let values = values.into_boxed_slice();	15✔
193
194	PartialArray {
195	index: SparseIndex {	10✔
196	ef: ef_dict,
197	first_invalid_pos: self.min_next_pos,
198	},
199	values,
200	_marker: PhantomData,
201	}
202	}
203	}
204
205	/// Extends the builder with an iterator of (position, value) pairs.
206	///
207	/// Position must be in strictly increasing order. The first returned
208	/// position must be greater than the last position set.
209	impl<T> Extend<(usize, T)> for PartialArrayBuilder<T, BitVec<Box<[u64]>>> {
210	fn extend<I: IntoIterator<Item = (usize, T)>>(&mut self, iter: I) {	×
211	for (pos, val) in iter {	×
212	self.set(pos, val);	×
213	}
214	}
215	}
216
217	/// Extends the builder with an iterator of (position, value) pairs.
218	///
219	/// Position must be in strictly increasing order. The first returned
220	/// position must be greater than the last position set.
221	impl<T> Extend<(usize, T)> for PartialArrayBuilder<T, EliasFanoBuilder> {
222	fn extend<I: IntoIterator<Item = (usize, T)>>(&mut self, iter: I) {	×
223	for (pos, val) in iter {	×
224	self.set(pos, val);	×
225	}
226	}
227	}
228
229	/// An immutable partial array that supports efficient queries
230	/// in compacted storage.
231	///
232	/// This structure stores a partial array—an array in which only
233	/// some positions contain values. There is a [dense](new_dense)
234	/// and a [sparse](new_sparse) implementation with different
235	/// space/time trade-offs.
236	///
237	/// For convenience, this structure implements [`SliceByValue`].
238	///
239	/// See [`PartialArrayBuilder`] for details on how to create a partial array.
240	#[derive(Debug, Clone, MemDbg, MemSize)]
241	#[cfg_attr(feature = "epserde", derive(epserde::Epserde))]
242	#[cfg_attr(feature = "serde", derive(serde::Serialize, serde::Deserialize))]
243	pub struct PartialArray<T, P, V: AsRef<[T]> = Box<[T]>> {
244	index: P,
245	values: V,
246	_marker: PhantomData<T>,
247	}
248
249	impl<T, P, V: AsRef<[T]>> PartialArray<T, P, V> {
250	/// Returns the number of values stored in the array.
251	#[inline(always)]
252	pub fn num_values(&self) -> usize {	8✔
253	self.values.as_ref().len()	16✔
254	}
255	}
256
257	impl<T, V: AsRef<[T]>> PartialArray<T, DenseIndex, V> {
258	/// Returns the total length of the array.
259	///
260	/// This is the length that was specified when creating the builder,
261	/// not the number of values actually stored.
262	#[inline(always)]
263	pub fn len(&self) -> usize {	1,014✔
264	self.index.len()	2,028✔
265	}
266
267	/// Returns true if the array length is 0.
268	#[inline(always)]
269	pub fn is_empty(&self) -> bool {	1✔
270	self.len() == 0	1✔
271	}
272
273	/// Gets a reference to the value at the given position.
274	///
275	/// Returns `Some(&value)` if a value is present at the position,
276	/// or `None` if no value was stored there.
277	///
278	/// # Examples
279	///
280	/// ```rust
281	/// # use sux::array::partial_array;
282	/// let mut builder = partial_array::new_dense(10);
283	/// builder.set(5, 42);
284	///
285	/// let array = builder.build();
286	/// assert_eq!(array.get(5), Some(&42));
287	/// assert_eq!(array.get(6), None);
288	/// ```
289	pub fn get(&self, position: usize) -> Option<&T> {	1,011✔
290	panic_if_out_of_bounds!(position, self.len());	2,024✔
291
292	// SAFETY: we just checked
293	unsafe { self.get_unchecked(position) }	3,030✔
294	}
295
296	/// # Safety
297	///
298	/// position < len()
299	pub unsafe fn get_unchecked(&self, position: usize) -> Option<&T> {	1,010✔
300	// Check if there's a value at this position
301	// SAFETY: position < len() guaranteed by caller
302	if !unsafe { self.index.get_unchecked(position) } {	2,020✔
303	return None;	1,006✔
304	}
305
306	// Use ranking to find the index in the values array
307	// SAFETY: position < len() guaranteed by caller
308	let value_index = unsafe { self.index.rank_unchecked(position) };	16✔
309
310	// SAFETY: necessarily value_index < num_values().
311	Some(unsafe { self.values.as_ref().get_unchecked(value_index) })	8✔
312	}
313	}
314
315	impl<T, D: Backend<Word = usize> + AsRef<[usize]>, V: AsRef<[T]>>
316	PartialArray<T, SparseIndex<D>, V>
317	{
318	/// Returns the total length of the array.
319	///
320	/// This is the length that was specified when creating the builder,
321	/// not the number of values actually stored.
322	#[inline(always)]
323	pub fn len(&self) -> usize {	1,033✔
324	self.index.ef.upper_bound() as usize	1,033✔
325	}
326
327	/// Returns true if the array len is 0.
328	#[inline(always)]
329	pub fn is_empty(&self) -> bool {	1✔
330	self.index.ef.upper_bound() == 0	1✔
331	}
332
333	/// Gets a reference to the value at the given position.
334	///
335	/// Returns `Some(&value)` if a value is present at the position,
336	/// or `None` if no value was stored there.
337	///
338	/// # Examples
339	///
340	/// ```rust
341	/// # use sux::array::partial_array;
342	/// let mut builder = partial_array::new_sparse(10, 1);
343	/// builder.set(5, 42);
344	///
345	/// let array = builder.build();
346	/// assert_eq!(array.get(5), Some(&42));
347	/// assert_eq!(array.get(6), None);
348	/// ```
349	pub fn get(&self, position: usize) -> Option<&T> {	1,031✔
350	panic_if_out_of_bounds!(position, self.len());	2,064✔
351
352	// SAFETY: we just checked
353	unsafe { self.get_unchecked(position) }	3,090✔
354	}
355
356	/// # Safety
357	///
358	/// position < len()
359	pub unsafe fn get_unchecked(&self, position: usize) -> Option<&T> {	1,030✔
360	if position >= self.index.first_invalid_pos {	1,030✔
361	return None;	505✔
362	}
363	// Check if there's a value at this position
364	// SAFETY: position <= last set position
365	let (index, pos) = unsafe { self.index.ef.succ_unchecked::<false>(position as u64) };	2,100✔
366
367	if pos != position as u64 {	525✔
368	None	515✔
369	} else {
370	// SAFETY: necessarily value_index < num values.
371	Some(unsafe { self.values.as_ref().get_unchecked(index) })	20✔
372	}
373	}
374	}
375
376	/// Returns an option even when using `get_value_unchecked` because it should be safe to call
377	/// whenever `position < len()`.
378	impl<T: Clone, V: AsRef<[T]>> SliceByValue for PartialArray<T, DenseIndex, V> {
379	type Value = Option<T>;
380
381	fn len(&self) -> usize {	×
382	self.len()	×
383	}
384
385	unsafe fn get_value_unchecked(&self, position: usize) -> Self::Value {	×
386	// SAFETY: position < len() guaranteed by caller
387	unsafe { self.get_unchecked(position) }.cloned()	×
388	}
389	}
390
391	/// Returns an option even when using `get_value_unchecked` because it should be safe to call
392	/// whenever `position < len()`.
393	impl<T: Clone, D: Backend<Word = usize> + AsRef<[usize]>, V: AsRef<[T]>> SliceByValue
394	for PartialArray<T, SparseIndex<D>, V>
395	{
396	type Value = Option<T>;
397
398	fn len(&self) -> usize {	×
399	self.len()	×
400	}
401
402	unsafe fn get_value_unchecked(&self, position: usize) -> Self::Value {	×
403	// SAFETY: position < len() guaranteed by caller
404	unsafe { self.get_unchecked(position) }.cloned()	×
405	}
406	}

vigna / sux-rs / 23354375031

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