/rust/registry/src/index.crates.io-6f17d22bba15001f/rayon-1.10.0/src/iter/positions.rs

Source (jump to first uncovered line)
use super::plumbing::*;
use super::*;

use std::fmt::{self, Debug};

/// `Positions` takes a predicate `predicate` and filters out elements that match,
/// yielding their indices.
///
/// This struct is created by the [`positions()`] method on [`IndexedParallelIterator`]
///
/// [`positions()`]: trait.IndexedParallelIterator.html#method.positions
/// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html
#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
#[derive(Clone)]
pub struct Positions<I: IndexedParallelIterator, P> {
    base: I,
    predicate: P,
}

impl<I: IndexedParallelIterator + Debug, P> Debug for Positions<I, P> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("Positions")
            .field("base", &self.base)
            .finish()
    }
}

impl<I, P> Positions<I, P>
where
    I: IndexedParallelIterator,
{
    /// Create a new `Positions` iterator.
    pub(super) fn new(base: I, predicate: P) -> Self {
        Positions { base, predicate }
    }
}

impl<I, P> ParallelIterator for Positions<I, P>
where
    I: IndexedParallelIterator,
    P: Fn(I::Item) -> bool + Sync + Send,
{
    type Item = usize;

    fn drive_unindexed<C>(self, consumer: C) -> C::Result
    where
        C: UnindexedConsumer<Self::Item>,
    {
        let consumer1 = PositionsConsumer::new(consumer, &self.predicate, 0);
        self.base.drive(consumer1)
    }
}

/// ////////////////////////////////////////////////////////////////////////
/// Consumer implementation

struct PositionsConsumer<'p, C, P> {
    base: C,
    predicate: &'p P,
    offset: usize,
}

impl<'p, C, P> PositionsConsumer<'p, C, P> {
    fn new(base: C, predicate: &'p P, offset: usize) -> Self {
        PositionsConsumer {
            base,
            predicate,
            offset,
        }
    }
}

impl<'p, T, C, P> Consumer<T> for PositionsConsumer<'p, C, P>
where
    C: Consumer<usize>,
    P: Fn(T) -> bool + Sync,
{
    type Folder = PositionsFolder<'p, C::Folder, P>;
    type Reducer = C::Reducer;
    type Result = C::Result;

    fn split_at(self, index: usize) -> (Self, Self, C::Reducer) {
        let (left, right, reducer) = self.base.split_at(index);
        (
            PositionsConsumer::new(left, self.predicate, self.offset),
            PositionsConsumer::new(right, self.predicate, self.offset + index),
            reducer,
        )
    }

    fn into_folder(self) -> Self::Folder {
        PositionsFolder {
            base: self.base.into_folder(),
            predicate: self.predicate,
            offset: self.offset,
        }
    }

    fn full(&self) -> bool {
        self.base.full()
    }
}

struct PositionsFolder<'p, F, P> {
    base: F,
    predicate: &'p P,
    offset: usize,
}

impl<F, P, T> Folder<T> for PositionsFolder<'_, F, P>
where
    F: Folder<usize>,
    P: Fn(T) -> bool,
{
    type Result = F::Result;

    fn consume(mut self, item: T) -> Self {
        let index = self.offset;
        self.offset += 1;
        if (self.predicate)(item) {
            self.base = self.base.consume(index);
        }
        self
    }

    // This cannot easily specialize `consume_iter` to be better than
    // the default, because that requires checking `self.base.full()`
    // during a call to `self.base.consume_iter()`. (#632)

    fn complete(self) -> Self::Result {
        self.base.complete()
    }

    fn full(&self) -> bool {
        self.base.full()
    }
}

Line	Count	Source (jump to first uncovered line)
1		use super::plumbing::*;
2		use super::*;
3
4		use std::fmt::{self, Debug};
5
6		/// `Positions` takes a predicate `predicate` and filters out elements that match,
7		/// yielding their indices.
8		///
9		/// This struct is created by the [`positions()`] method on [`IndexedParallelIterator`]
10		///
11		/// [`positions()`]: trait.IndexedParallelIterator.html#method.positions
12		/// [`IndexedParallelIterator`]: trait.IndexedParallelIterator.html
13		#[must_use = "iterator adaptors are lazy and do nothing unless consumed"]
14		#[derive(Clone)]
15		pub struct Positions<I: IndexedParallelIterator, P> {
16		base: I,
17		predicate: P,
18		}
19
20		impl<I: IndexedParallelIterator + Debug, P> Debug for Positions<I, P> {
21	0	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
22	0	f.debug_struct("Positions")
23	0	.field("base", &self.base)
24	0	.finish()
25	0	}
26		}
27
28		impl<I, P> Positions<I, P>
29		where
30		I: IndexedParallelIterator,
31		{
32		/// Create a new `Positions` iterator.
33	0	pub(super) fn new(base: I, predicate: P) -> Self {
34	0	Positions { base, predicate }
35	0	}
36		}
37
38		impl<I, P> ParallelIterator for Positions<I, P>
39		where
40		I: IndexedParallelIterator,
41		P: Fn(I::Item) -> bool + Sync + Send,
42		{
43		type Item = usize;
44
45	0	fn drive_unindexed<C>(self, consumer: C) -> C::Result
46	0	where
47	0	C: UnindexedConsumer<Self::Item>,
48	0	{
49	0	let consumer1 = PositionsConsumer::new(consumer, &self.predicate, 0);
50	0	self.base.drive(consumer1)
51	0	}
52		}
53
54		/// ////////////////////////////////////////////////////////////////////////
55		/// Consumer implementation
56
57		struct PositionsConsumer<'p, C, P> {
58		base: C,
59		predicate: &'p P,
60		offset: usize,
61		}
62
63		impl<'p, C, P> PositionsConsumer<'p, C, P> {
64	0	fn new(base: C, predicate: &'p P, offset: usize) -> Self {
65	0	PositionsConsumer {
66	0	base,
67	0	predicate,
68	0	offset,
69	0	}
70	0	}
71		}
72
73		impl<'p, T, C, P> Consumer<T> for PositionsConsumer<'p, C, P>
74		where
75		C: Consumer<usize>,
76		P: Fn(T) -> bool + Sync,
77		{
78		type Folder = PositionsFolder<'p, C::Folder, P>;
79		type Reducer = C::Reducer;
80		type Result = C::Result;
81
82	0	fn split_at(self, index: usize) -> (Self, Self, C::Reducer) {
83	0	let (left, right, reducer) = self.base.split_at(index);
84	0	(
85	0	PositionsConsumer::new(left, self.predicate, self.offset),
86	0	PositionsConsumer::new(right, self.predicate, self.offset + index),
87	0	reducer,
88	0	)
89	0	}
90
91	0	fn into_folder(self) -> Self::Folder {
92	0	PositionsFolder {
93	0	base: self.base.into_folder(),
94	0	predicate: self.predicate,
95	0	offset: self.offset,
96	0	}
97	0	}
98
99	0	fn full(&self) -> bool {
100	0	self.base.full()
101	0	}
102		}
103
104		struct PositionsFolder<'p, F, P> {
105		base: F,
106		predicate: &'p P,
107		offset: usize,
108		}
109
110		impl<F, P, T> Folder<T> for PositionsFolder<'_, F, P>
111		where
112		F: Folder<usize>,
113		P: Fn(T) -> bool,
114		{
115		type Result = F::Result;
116
117	0	fn consume(mut self, item: T) -> Self {
118	0	let index = self.offset;
119	0	self.offset += 1;
120	0	if (self.predicate)(item) {
121	0	self.base = self.base.consume(index);
122	0	}
123	0	self
124	0	}
125
126		// This cannot easily specialize `consume_iter` to be better than
127		// the default, because that requires checking `self.base.full()`
128		// during a call to `self.base.consume_iter()`. (#632)
129
130	0	fn complete(self) -> Self::Result {
131	0	self.base.complete()
132	0	}
133
134	0	fn full(&self) -> bool {
135	0	self.base.full()
136	0	}
137		}

Coverage Report

Created: 2025-02-21 07:11