Struct encode_unicode::Utf16Char

pub struct Utf16Char { /* fields omitted */ }

An unicode codepoint stored as UTF-16.

It can be borrowed as an u16 slice, and has the same size as char.

Methods

impl Utf16Char

fn from_slice_start(src: &[u16]) -> Result<(Self, usize), InvalidUtf16Slice>

Validate and store the first UTF-16 codepoint in the slice. Also return how many units were needed.

unsafe fn from_slice_start_unchecked(src: &[u16]) -> (Self, usize)

Store the first UTF-16 codepoint of the slice.

Safety

The slice must be non-empty and start with a valid UTF-16 codepoint.
The length of the slice is never checked.

fn from_tuple(utf16: (u16, Option<u16>)) -> Result<Self, InvalidUtf16Tuple>

Validate and store a UTF-16 pair as returned from char.to_utf16_tuple().

unsafe fn from_tuple_unchecked(utf16: (u16, Option<u16>)) -> Self

Create an Utf16Char from a tuple as returned from char.to_utf16_tuple().

Safety

The units must represent a single valid codepoint.

fn len(self) -> usize

Returns 1 or 2. There is no .is_emty() because it would always return false.

fn to_char(self) -> char

Convert from UTF-16 to UTF-32

fn to_slice(self, dst: &mut [u16]) -> usize

Write the internal representation to a slice, and then returns the number of u16s written.

Panics

Will panic the buffer is too small; You can get the required length from .len(), but a buffer of length two is always large enough.

fn to_tuple(self) -> (u16, Option<u16>)

The second u16 is used for surrogate pairs.

Methods from Deref<Target=[u16]>

fn len(&self) -> usize

Returns the number of elements in the slice.

Example

let a = [1, 2, 3];
assert_eq!(a.len(), 3);

fn is_empty(&self) -> bool

Returns true if the slice has a length of 0.

Example

let a = [1, 2, 3];
assert!(!a.is_empty());

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

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

Examples

let v = [10, 40, 30];
assert_eq!(Some(&10), v.first());

let w: &[i32] = &[];
assert_eq!(None, w.first());

fn split_first(&self) -> Option<(&T, &[T])>

Returns the first and all the rest of the elements of a slice.

Examples

let x = &[0, 1, 2];

if let Some((first, elements)) = x.split_first() {
    assert_eq!(first, &0);
    assert_eq!(elements, &[1, 2]);
}

fn split_last(&self) -> Option<(&T, &[T])>

Returns the last and all the rest of the elements of a slice.

Examples

let x = &[0, 1, 2];

if let Some((last, elements)) = x.split_last() {
    assert_eq!(last, &2);
    assert_eq!(elements, &[0, 1]);
}

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

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

Examples

let v = [10, 40, 30];
assert_eq!(Some(&30), v.last());

let w: &[i32] = &[];
assert_eq!(None, w.last());

fn get<I>(&self, index: I) -> Option<&I::Output> where I: SliceIndex<T>

Returns a reference to an element or subslice depending on the type of index.

• If given a position, returns a reference to the element at that position or None if out of bounds.
• If given a range, returns the subslice corresponding to that range, or None if out of bounds.

Examples

let v = [10, 40, 30];
assert_eq!(Some(&40), v.get(1));
assert_eq!(Some(&[10, 40][..]), v.get(0..2));
assert_eq!(None, v.get(3));
assert_eq!(None, v.get(0..4));

unsafe fn get_unchecked<I>(&self, index: I) -> &I::Output where I: SliceIndex<T>

Returns a reference to an element or subslice, without doing bounds checking. So use it very carefully!

Examples

let x = &[1, 2, 4];

unsafe {
    assert_eq!(x.get_unchecked(1), &2);
}

fn as_ptr(&self) -> *const T

Returns a raw 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.

Examples

let x = &[1, 2, 4];
let x_ptr = x.as_ptr();

unsafe {
    for i in 0..x.len() {
        assert_eq!(x.get_unchecked(i), &*x_ptr.offset(i as isize));
    }
}

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

Returns an iterator over the slice.

Examples

let x = &[1, 2, 4];
let mut iterator = x.iter();

assert_eq!(iterator.next(), Some(&1));
assert_eq!(iterator.next(), Some(&2));
assert_eq!(iterator.next(), Some(&4));
assert_eq!(iterator.next(), None);

fn windows(&self, size: usize) -> 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

let slice = ['r', 'u', 's', 't'];
let mut iter = slice.windows(2);
assert_eq!(iter.next().unwrap(), &['r', 'u']);
assert_eq!(iter.next().unwrap(), &['u', 's']);
assert_eq!(iter.next().unwrap(), &['s', 't']);
assert!(iter.next().is_none());

If the slice is shorter than size:

let slice = ['f', 'o', 'o'];
let mut iter = slice.windows(4);
assert!(iter.next().is_none());

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

Returns an iterator over size elements of the slice at a time. The chunks are slices and 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

let slice = ['l', 'o', 'r', 'e', 'm'];
let mut iter = slice.chunks(2);
assert_eq!(iter.next().unwrap(), &['l', 'o']);
assert_eq!(iter.next().unwrap(), &['r', 'e']);
assert_eq!(iter.next().unwrap(), &['m']);
assert!(iter.next().is_none());

fn split_at(&self, mid: usize) -> (&[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

Panics if mid > len.

Examples

let v = [10, 40, 30, 20, 50];
let (v1, v2) = v.split_at(2);
assert_eq!([10, 40], v1);
assert_eq!([30, 20, 50], v2);

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.

Examples

let slice = [10, 40, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

If the first element is matched, an empty slice will be the first item returned by the iterator. Similarly, if the last element in the slice is matched, an empty slice will be the last item returned by the iterator:

let slice = [10, 40, 33];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10, 40]);
assert_eq!(iter.next().unwrap(), &[]);
assert!(iter.next().is_none());

If two matched elements are directly adjacent, an empty slice will be present between them:

let slice = [10, 6, 33, 20];
let mut iter = slice.split(|num| num % 3 == 0);

assert_eq!(iter.next().unwrap(), &[10]);
assert_eq!(iter.next().unwrap(), &[]);
assert_eq!(iter.next().unwrap(), &[20]);
assert!(iter.next().is_none());

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

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

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once by numbers divisible by 3 (i.e. [10, 40], [20, 60, 50]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.splitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

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

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

The last element returned, if any, will contain the remainder of the slice.

Examples

Print the slice split once, starting from the end, by numbers divisible by 3 (i.e. [50], [10, 40, 30, 20]):

let v = [10, 40, 30, 20, 60, 50];

for group in v.rsplitn(2, |num| *num % 3 == 0) {
    println!("{:?}", group);
}

fn contains(&self, x: &T) -> bool where T: PartialEq<T>

Returns true if the slice contains an element with the given value.

Examples

let v = [10, 40, 30];
assert!(v.contains(&30));
assert!(!v.contains(&50));

fn starts_with(&self, needle: &[T]) -> bool where T: PartialEq<T>

Returns true if needle is a prefix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.starts_with(&[10]));
assert!(v.starts_with(&[10, 40]));
assert!(!v.starts_with(&[50]));
assert!(!v.starts_with(&[10, 50]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.starts_with(&[]));
let v: &[u8] = &[];
assert!(v.starts_with(&[]));

fn ends_with(&self, needle: &[T]) -> bool where T: PartialEq<T>

Returns true if needle is a suffix of the slice.

Examples

let v = [10, 40, 30];
assert!(v.ends_with(&[30]));
assert!(v.ends_with(&[40, 30]));
assert!(!v.ends_with(&[50]));
assert!(!v.ends_with(&[50, 30]));

Always returns true if needle is an empty slice:

let v = &[10, 40, 30];
assert!(v.ends_with(&[]));
let v: &[u8] = &[];
assert!(v.ends_with(&[]));

fn binary_search(&self, x: &T) -> Result<usize, usize> where T: Ord

Binary search a sorted slice for a given element.

If the value is found then Ok is returned, containing the index of the matching element; if the value is not 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].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

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

fn binary_search_by<'a, F>(&'a self, f: F) -> Result<usize, usize> where F: FnMut(&'a 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].

let s = [0, 1, 1, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55];

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 binary_search_by_key<'a, B, F>(&'a self, b: &B, f: F) -> Result<usize, usize> where B: Ord, F: FnMut(&'a T) -> B

Binary search a sorted slice with a key extraction function.

Assumes that the slice is sorted by the key, for instance with sort_by_key using the same key extraction function.

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.

Examples

Looks up a series of four elements in a slice of pairs sorted by their second 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].

let s = [(0, 0), (2, 1), (4, 1), (5, 1), (3, 1),
         (1, 2), (2, 3), (4, 5), (5, 8), (3, 13),
         (1, 21), (2, 34), (4, 55)];

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

fn to_vec(&self) -> Vec<T> where T: Clone

Copies self into a new Vec.

Examples

let s = [10, 40, 30];
let x = s.to_vec();
// Here, `s` and `x` can be modified independently.

fn into_vec(self: Box<[T]>) -> Vec<T>

Converts self into a vector without clones or allocation.

Examples

let s: Box<[i32]> = Box::new([10, 40, 30]);
let x = s.into_vec();
// `s` cannot be used anymore because it has been converted into `x`.

assert_eq!(x, vec![10, 40, 30]);

Trait Implementations

impl Default for Utf16Char

fn default() -> Utf16Char

Returns the "default value" for a type.

impl PartialEq for Utf16Char

fn eq(&self, __arg_0: &Utf16Char) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, __arg_0: &Utf16Char) -> bool

This method tests for !=.

impl Eq for Utf16Char

impl Clone for Utf16Char

fn clone(&self) -> Utf16Char

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for Utf16Char

impl From<char> for Utf16Char

fn from(c: char) -> Self

Performs the conversion.

impl From<Utf8Char> for Utf16Char

fn from(utf8: Utf8Char) -> Utf16Char

Performs the conversion.

impl IntoIterator for Utf16Char

type Item = u16

The type of the elements being iterated over.

type IntoIter = Utf16Iterator

Which kind of iterator are we turning this into?

fn into_iter(self) -> Utf16Iterator

Iterate over the units.

impl AsRef<[u16]> for Utf16Char

fn as_ref(&self) -> &[u16]

Performs the conversion.

impl Borrow<[u16]> for Utf16Char

fn borrow(&self) -> &[u16]

Immutably borrows from an owned value.

impl Deref for Utf16Char

type Target = [u16]

The resulting type after dereferencing

fn deref(&self) -> &[u16]

The method called to dereference a value

impl AsciiExt for Utf16Char

type Owned = Self

Container type for copied ASCII characters.

fn is_ascii(&self) -> bool

Checks if the value is within the ASCII range.

fn eq_ignore_ascii_case(&self, other: &Self) -> bool

Checks that two strings are an ASCII case-insensitive match.

fn to_ascii_uppercase(&self) -> Self

Makes a copy of the string in ASCII upper case.

fn to_ascii_lowercase(&self) -> Self

Makes a copy of the string in ASCII lower case.

fn make_ascii_uppercase(&mut self)

Converts this type to its ASCII upper case equivalent in-place.

fn make_ascii_lowercase(&mut self)

Converts this type to its ASCII lower case equivalent in-place.

fn is_ascii_alphabetic(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII alphabetic character: U+0041 'A' ... U+005A 'Z' or U+0061 'a' ... U+007A 'z'. For strings, true if all characters in the string are ASCII alphabetic.

fn is_ascii_uppercase(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII uppercase character: U+0041 'A' ... U+005A 'Z'. For strings, true if all characters in the string are ASCII uppercase.

fn is_ascii_lowercase(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII lowercase character: U+0061 'a' ... U+007A 'z'. For strings, true if all characters in the string are ASCII lowercase.

fn is_ascii_alphanumeric(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII alphanumeric character: U+0041 'A' ... U+005A 'Z', U+0061 'a' ... U+007A 'z', or U+0030 '0' ... U+0039 '9'. For strings, true if all characters in the string are ASCII alphanumeric.

fn is_ascii_digit(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII decimal digit: U+0030 '0' ... U+0039 '9'. For strings, true if all characters in the string are ASCII digits.

fn is_ascii_hexdigit(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII hexadecimal digit: U+0030 '0' ... U+0039 '9', U+0041 'A' ... U+0046 'F', or U+0061 'a' ... U+0066 'f'. For strings, true if all characters in the string are ASCII hex digits.

fn is_ascii_punctuation(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII punctuation character: U+0021 ... U+002F ! " # $ % & ' ( ) * + , - . / U+003A ... U+0040 : ; < = > ? @ U+005B ... U+0060 [ \ ] ^ _U+007B ... U+007E{ | } ~` For strings, true if all characters in the string are ASCII punctuation.

fn is_ascii_graphic(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII graphic character: U+0021 '@' ... U+007E '~'. For strings, true if all characters in the string are ASCII punctuation.

fn is_ascii_whitespace(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII whitespace character: U+0020 SPACE, U+0009 HORIZONTAL TAB, U+000A LINE FEED, U+000C FORM FEED, or U+000D CARRIAGE RETURN. For strings, true if all characters in the string are ASCII whitespace.

fn is_ascii_control(&self) -> bool

🔬 This is a nightly-only experimental API. (ascii_ctype)

Checks if the value is an ASCII control character: U+0000 NUL ... U+001F UNIT SEPARATOR, or U+007F DELETE. Note that most ASCII whitespace characters are control characters, but SPACE is not.

impl From<AsciiChar> for Utf16Char

Requires the feature "ascii".

fn from(ac: AsciiChar) -> Self

Performs the conversion.

impl ToAsciiChar for Utf16Char

Requires the feature "ascii".

fn to_ascii_char(self) -> Result<AsciiChar, ToAsciiCharError>

Convert to AsciiChar.

unsafe fn to_ascii_char_unchecked(self) -> AsciiChar

Convert to AsciiChar without checking that it is an ASCII character.

impl Hash for Utf16Char

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the state given, updating the hasher as necessary.

fn hash_slice<H>(data: &[Self], state: &mut H) where H: Hasher

Feeds a slice of this type into the state provided.

impl Debug for Utf16Char

fn fmt(&self, fmtr: &mut Formatter) -> Result

Formats the value using the given formatter.

impl Display for Utf16Char

fn fmt(&self, fmtr: &mut Formatter) -> Result

Formats the value using the given formatter.

impl PartialOrd for Utf16Char

fn partial_cmp(&self, rhs: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

This method tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

This method tests greater than or equal to (for self and other) and is used by the >= operator.

impl Ord for Utf16Char

fn cmp(&self, rhs: &Self) -> Ordering

This method returns an Ordering between self and other.