Trait collections::slice::SliceExtUnstable [-]  [+] [src]

pub trait SliceExt<T>: ?Sized {
    fn sort_by<F>(&mut self, compare: F) where F: FnMut(&T, &T) -> Ordering;
    fn move_from(&mut self, src: Vec<T>, start: uint, end: uint) -> uint;
    fn slice(&self, start: uint, end: uint) -> &[T];
    fn slice_from(&self, start: uint) -> &[T];
    fn slice_to(&self, end: uint) -> &[T];
    fn split_at(&self, mid: uint) -> (&[T], &[T]);
    fn iter(&self) -> Iter<T>;
    fn split<F>(&self, pred: F) -> Split<T, F> where F: FnMut(&T) -> bool;
    fn splitn<F>(&self, n: uint, pred: F) -> SplitN<T, F> where F: FnMut(&T) -> bool;
    fn rsplitn<F>(&self, n: uint, pred: F) -> RSplitN<T, F> where F: FnMut(&T) -> bool;
    fn windows(&self, size: uint) -> Windows<T>;
    fn chunks(&self, size: uint) -> Chunks<T>;
    fn get(&self, index: uint) -> Option<&T>;
    fn first(&self) -> Option<&T>;
    fn tail(&self) -> &[T];
    fn init(&self) -> &[T];
    fn last(&self) -> Option<&T>;
    unsafe fn get_unchecked(&self, index: uint) -> &T;
    fn as_ptr(&self) -> *const T;
    fn binary_search_by<F>(&self, f: F) -> Result<uint, uint> where F: FnMut(&T) -> Ordering;
    fn len(&self) -> uint;
    fn get_mut(&mut self, index: uint) -> Option<&mut T>;
    fn as_mut_slice(&mut self) -> &mut [T];
    fn slice_mut(&mut self, start: uint, end: uint) -> &mut [T];
    fn slice_from_mut(&mut self, start: uint) -> &mut [T];
    fn slice_to_mut(&mut self, end: uint) -> &mut [T];
    fn iter_mut(&mut self) -> IterMut<T>;
    fn first_mut(&mut self) -> Option<&mut T>;
    fn tail_mut(&mut self) -> &mut [T];
    fn init_mut(&mut self) -> &mut [T];
    fn last_mut(&mut self) -> Option<&mut T>;
    fn split_mut<F>(&mut self, pred: F) -> SplitMut<T, F> where F: FnMut(&T) -> bool;
    fn splitn_mut<F>(&mut self, n: uint, pred: F) -> SplitNMut<T, F> where F: FnMut(&T) -> bool;
    fn rsplitn_mut<F>(&mut self, n: uint, pred: F) -> RSplitNMut<T, F> where F: FnMut(&T) -> bool;
    fn chunks_mut(&mut self, chunk_size: uint) -> ChunksMut<T>;
    fn swap(&mut self, a: uint, b: uint);
    fn split_at_mut(&mut self, mid: uint) -> (&mut [T], &mut [T]);
    fn reverse(&mut self);
    unsafe fn get_unchecked_mut(&mut self, index: uint) -> &mut T;
    fn as_mut_ptr(&mut self) -> *mut T;

    fn head(&self) -> Option<&T> { ... }
    unsafe fn unsafe_get(&self, index: uint) -> &T { ... }
    fn is_empty(&self) -> bool { ... }
    fn head_mut(&mut self) -> Option<&mut T> { ... }
    unsafe fn unchecked_mut(&mut self, index: uint) -> &mut T { ... }
}

Allocating extension methods for slices.

Required Methods

fn sort_by<F>(&mut self, compare: F) where F: FnMut(&T, &T) -> Ordering

Sorts the slice, in place, using compare to compare elements.

This sort is O(n log n) worst-case and stable, but allocates approximately 2 * n, where n is the length of self.

Examples

fn main() { let mut v = [5i, 4, 1, 3, 2]; v.sort_by(|a, b| a.cmp(b)); assert!(v == [1, 2, 3, 4, 5]); // reverse sorting v.sort_by(|a, b| b.cmp(a)); assert!(v == [5, 4, 3, 2, 1]); }
let mut v = [5i, 4, 1, 3, 2];
v.sort_by(|a, b| a.cmp(b));
assert!(v == [1, 2, 3, 4, 5]);

// reverse sorting
v.sort_by(|a, b| b.cmp(a));
assert!(v == [5, 4, 3, 2, 1]);

fn move_from(&mut self, src: Vec<T>, start: uint, end: uint) -> uint

Consumes src and moves as many elements as it can into self from the range [start,end).

Returns the number of elements copied (the shorter of self.len() and end - start).

Arguments

  • src - A mutable vector of T
  • start - The index into src to start copying from
  • end - The index into src to stop copying from

Examples

fn main() { let mut a = [1i, 2, 3, 4, 5]; let b = vec![6i, 7, 8]; let num_moved = a.move_from(b, 0, 3); assert_eq!(num_moved, 3); assert!(a == [6i, 7, 8, 4, 5]); }
let mut a = [1i, 2, 3, 4, 5];
let b = vec![6i, 7, 8];
let num_moved = a.move_from(b, 0, 3);
assert_eq!(num_moved, 3);
assert!(a == [6i, 7, 8, 4, 5]);

fn slice(&self, start: uint, end: uint) -> &[T]

Returns a subslice spanning the interval [start, end).

Panics when the end of the new slice lies beyond the end of the original slice (i.e. when end > self.len()) or when start > end.

Slicing with start equal to end yields an empty slice.

fn slice_from(&self, start: uint) -> &[T]

Returns a subslice from start to the end of the slice.

Panics when start is strictly greater than the length of the original slice.

Slicing from self.len() yields an empty slice.

fn slice_to(&self, end: uint) -> &[T]

Returns a subslice from the start of the slice to end.

Panics when end is strictly greater than the length of the original slice.

Slicing to 0 yields an empty slice.

fn split_at(&self, mid: uint) -> (&[T], &[T])

Divides one slice into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Panics if mid > len.

fn iter(&self) -> Iter<T>

Returns an iterator over the slice

fn split<F>(&self, pred: F) -> Split<T, F> where F: FnMut(&T) -> bool

Returns an iterator over subslices separated by elements that match pred. The matched element is not contained in the subslices.

fn splitn<F>(&self, n: uint, pred: F) -> SplitN<T, F> where F: FnMut(&T) -> bool

Returns an iterator over subslices separated by elements that match pred, limited to splitting at most n times. The matched element is not contained in the subslices.

fn rsplitn<F>(&self, n: uint, pred: F) -> RSplitN<T, F> where F: FnMut(&T) -> bool

Returns an iterator over subslices separated by elements that match pred limited to splitting at most n times. This starts at the end of the slice and works backwards. The matched element is not contained in the subslices.

fn windows(&self, size: uint) -> Windows<T>

Returns an iterator over all contiguous windows of length size. The windows overlap. If the slice is shorter than size, the iterator returns no values.

Panics

Panics if size is 0.

Example

Print the adjacent pairs of a slice (i.e. [1,2], [2,3], [3,4]):

fn main() { let v = &[1i, 2, 3, 4]; for win in v.windows(2) { println!("{}", win); } }
let v = &[1i, 2, 3, 4];
for win in v.windows(2) {
    println!("{}", win);
}

fn chunks(&self, size: uint) -> Chunks<T>

Returns an iterator over size elements of the slice at a time. The chunks do not overlap. If size does not divide the length of the slice, then the last chunk will not have length size.

Panics

Panics if size is 0.

Example

Print the slice two elements at a time (i.e. [1,2], [3,4], [5]):

fn main() { let v = &[1i, 2, 3, 4, 5]; for win in v.chunks(2) { println!("{}", win); } }
let v = &[1i, 2, 3, 4, 5];
for win in v.chunks(2) {
    println!("{}", win);
}

fn get(&self, index: uint) -> Option<&T>

Returns the element of a slice at the given index, or None if the index is out of bounds.

fn first(&self) -> Option<&T>

Returns the first element of a slice, or None if it is empty.

fn tail(&self) -> &[T]

Returns all but the first element of a slice.

fn init(&self) -> &[T]

Returns all but the last element of a slice.

fn last(&self) -> Option<&T>

Returns the last element of a slice, or None if it is empty.

unsafe fn get_unchecked(&self, index: uint) -> &T

Returns a pointer to the element at the given index, without doing bounds checking.

fn as_ptr(&self) -> *const T

Returns an unsafe pointer to the slice's buffer

The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.

Modifying the slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.

fn binary_search_by<F>(&self, f: F) -> Result<uint, uint> where F: FnMut(&T) -> Ordering

Binary search a sorted slice with a comparator function.

The comparator function should implement an order consistent with the sort order of the underlying slice, returning an order code that indicates whether its argument is Less, Equal or Greater the desired target.

If a matching value is found then returns Ok, containing the index for the matched element; if no match is found then Err is returned, containing the index where a matching element could be inserted while maintaining sorted order.

Example

Looks up a series of four elements. The first is found, with a uniquely determined position; the second and third are not found; the fourth could match any position in [1,4].

fn main() { let s = [0i, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55]; let s = s.as_slice(); let seek = 13; assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9)); let seek = 4; assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7)); let seek = 100; assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13)); let seek = 1; let r = s.binary_search_by(|probe| probe.cmp(&seek)); assert!(match r { Ok(1...4) => true, _ => false, }); }
let s = [0i, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];
let s = s.as_slice();

let seek = 13;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Ok(9));
let seek = 4;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(7));
let seek = 100;
assert_eq!(s.binary_search_by(|probe| probe.cmp(&seek)), Err(13));
let seek = 1;
let r = s.binary_search_by(|probe| probe.cmp(&seek));
assert!(match r { Ok(1...4) => true, _ => false, });

fn len(&self) -> uint

Return the number of elements in the slice

Example

fn main() { let a = [1i, 2, 3]; assert_eq!(a.len(), 3); }
let a = [1i, 2, 3];
assert_eq!(a.len(), 3);

fn get_mut(&mut self, index: uint) -> Option<&mut T>

Returns a mutable reference to the element at the given index, or None if the index is out of bounds

fn as_mut_slice(&mut self) -> &mut [T]

Work with self as a mut slice. Primarily intended for getting a &mut [T] from a [T, ..N].

fn slice_mut(&mut self, start: uint, end: uint) -> &mut [T]

Returns a mutable subslice spanning the interval [start, end).

Panics when the end of the new slice lies beyond the end of the original slice (i.e. when end > self.len()) or when start > end.

Slicing with start equal to end yields an empty slice.

fn slice_from_mut(&mut self, start: uint) -> &mut [T]

Returns a mutable subslice from start to the end of the slice.

Panics when start is strictly greater than the length of the original slice.

Slicing from self.len() yields an empty slice.

fn slice_to_mut(&mut self, end: uint) -> &mut [T]

Returns a mutable subslice from the start of the slice to end.

Panics when end is strictly greater than the length of the original slice.

Slicing to 0 yields an empty slice.

fn iter_mut(&mut self) -> IterMut<T>

Returns an iterator that allows modifying each value

fn first_mut(&mut self) -> Option<&mut T>

Returns a mutable pointer to the first element of a slice, or None if it is empty

fn tail_mut(&mut self) -> &mut [T]

Returns all but the first element of a mutable slice

fn init_mut(&mut self) -> &mut [T]

Returns all but the last element of a mutable slice

fn last_mut(&mut self) -> Option<&mut T>

Returns a mutable pointer to the last item in the slice.

fn split_mut<F>(&mut self, pred: F) -> SplitMut<T, F> where F: FnMut(&T) -> bool

Returns an iterator over mutable subslices separated by elements that match pred. The matched element is not contained in the subslices.

fn splitn_mut<F>(&mut self, n: uint, pred: F) -> SplitNMut<T, F> where F: FnMut(&T) -> bool

Returns an iterator over subslices separated by elements that match pred, limited to splitting at most n times. The matched element is not contained in the subslices.

fn rsplitn_mut<F>(&mut self, n: uint, pred: F) -> RSplitNMut<T, F> where F: FnMut(&T) -> bool

Returns an iterator over subslices separated by elements that match pred limited to splitting at most n times. This starts at the end of the slice and works backwards. The matched element is not contained in the subslices.

fn chunks_mut(&mut self, chunk_size: uint) -> ChunksMut<T>

Returns an iterator over chunk_size elements of the slice at a time. The chunks are mutable and do not overlap. If chunk_size does not divide the length of the slice, then the last chunk will not have length chunk_size.

Panics

Panics if chunk_size is 0.

fn swap(&mut self, a: uint, b: uint)

Swaps two elements in a slice.

Arguments

  • a - The index of the first element
  • b - The index of the second element

Panics

Panics if a or b are out of bounds.

Example

fn main() { let mut v = ["a", "b", "c", "d"]; v.swap(1, 3); assert!(v == ["a", "d", "c", "b"]); }
let mut v = ["a", "b", "c", "d"];
v.swap(1, 3);
assert!(v == ["a", "d", "c", "b"]);

fn split_at_mut(&mut self, mid: uint) -> (&mut [T], &mut [T])

Divides one &mut into two at an index.

The first will contain all indices from [0, mid) (excluding the index mid itself) and the second will contain all indices from [mid, len) (excluding the index len itself).

Panics

Panics if mid > len.

Example

fn main() { let mut v = [1i, 2, 3, 4, 5, 6]; // scoped to restrict the lifetime of the borrows { let (left, right) = v.split_at_mut(0); assert!(left == []); assert!(right == [1i, 2, 3, 4, 5, 6]); } { let (left, right) = v.split_at_mut(2); assert!(left == [1i, 2]); assert!(right == [3i, 4, 5, 6]); } { let (left, right) = v.split_at_mut(6); assert!(left == [1i, 2, 3, 4, 5, 6]); assert!(right == []); } }
let mut v = [1i, 2, 3, 4, 5, 6];

// scoped to restrict the lifetime of the borrows
{
   let (left, right) = v.split_at_mut(0);
   assert!(left == []);
   assert!(right == [1i, 2, 3, 4, 5, 6]);
}

{
    let (left, right) = v.split_at_mut(2);
    assert!(left == [1i, 2]);
    assert!(right == [3i, 4, 5, 6]);
}

{
    let (left, right) = v.split_at_mut(6);
    assert!(left == [1i, 2, 3, 4, 5, 6]);
    assert!(right == []);
}

fn reverse(&mut self)

Reverse the order of elements in a slice, in place.

Example

fn main() { let mut v = [1i, 2, 3]; v.reverse(); assert!(v == [3i, 2, 1]); }
let mut v = [1i, 2, 3];
v.reverse();
assert!(v == [3i, 2, 1]);

unsafe fn get_unchecked_mut(&mut self, index: uint) -> &mut T

Returns an unsafe mutable pointer to the element in index

fn as_mut_ptr(&mut self) -> *mut T

Return an unsafe mutable pointer to the slice's buffer.

The caller must ensure that the slice outlives the pointer this function returns, or else it will end up pointing to garbage.

Modifying the slice may cause its buffer to be reallocated, which would also make any pointers to it invalid.

Provided Methods

fn head(&self) -> Option<&T>

Deprecated: renamed to first.

unsafe fn unsafe_get(&self, index: uint) -> &T

Deprecated: renamed to get_unchecked.

fn is_empty(&self) -> bool

Returns true if the slice has a length of 0

Example

fn main() { let a = [1i, 2, 3]; assert!(!a.is_empty()); }
let a = [1i, 2, 3];
assert!(!a.is_empty());

fn head_mut(&mut self) -> Option<&mut T>

Depreated: renamed to first_mut.

unsafe fn unchecked_mut(&mut self, index: uint) -> &mut T

Deprecated: renamed to get_unchecked_mut.

Implementors